design & mitigation of blast resistant doors (numerical analysis)

DESIGN AND MITIGATION OF BLAST RESISTANT

DOORSA PROJECT REPORT

Submitted by

AVHISHEK SINGH [Reg No-11UEME0034]

In partial fulfilment for the award of the degree

Of

BACHELOR OF TECHNOLOGYIN

MECHANICAL ENGINEERING

VEL TECH DR.RR & DR.SR TECHNICAL

UNIVERSITY: CHENNAI 600062

APRIL 2015

Defence Research & Development Organization Ministry of Defence, Govt. of India

BONAFIDE CERTIFICATE

Certified that this project report “DESIGN AND MITIGATION OF

RESISTANT DOORS” is the bonafide work of “AVHISHEK SINGH

(11UEME0034)”, who carried out the project work under my supervision

SIGNATURE SIGNATUREMr. Herbans Lal Mr. Ashok KumarScientist ‘G’ Group Head Scientist ‘D’ (CFEES) DRDONew Delhi New Delhi

AKNOWLEDGEMENT

The internship opportunity I had with Defence research and Development

Organization (DRDO), was a great chance for learning and professional

development. Therefore I consider myself as a very lucky individual to be

considered a part of it.

I’m pleased to bring out our project “Deaign & Mitigation of Blast Resistant

Doors” for the field of Engineering and Technology.

I would take this opportunity to express my deepest gratitude to Mr. Ashok

Kumar (Scientist D) who in spite of being extraordinarily busy with his duties,

took time to hear, guide and keep me on the correct path and allowing me to

carry out my project work on this esteemed organization.

I’m extremely grateful to honorable Dr. Chitra Rajagopal, Director of

CFEES for immediate approval, constant encouragement and for giving me the

opportunity to do internship in this esteemed orginisation.

My Special thanks to Mr. Rajender Singh for Constant encouragement and

moral support. I chose this moment to acknowledge his contribution gratefully.

I sincerely express my deepest thanks to Mr. Harbans Lal (Group Head) for

taking useful decision and giving me necessary advices. I would further like to

express my gratitude for his carefull and precious guidance which was

extremely helpful for my studies.

My sincere thanks to Mr. Jayavelu. S, M.E., Head of Department, School of

Mechanical, Vel Tech Dr. RR & Dr. SR Technical University, Chennai, for his

involvement to make this project successful.

I express my deepest thanks to Mr. Awahedesh Kumar for taking useful

decisions & giving me necessary advices and guidance. I choose this moment to

acknowledge his contribution gratefully.

I perceive this opportunity as a big milestone with regard to my career

development. I will strive to use the gained knowledge in the best possible way

and I will continue to work on their improvement in order to attain desired

career objectives.

Any omission in this brief acknowledgment does not mean lack of gratitude.

Avhishek Singh

Vel Tech DR.RR & DR.SR Technical University,

Chennai

Abstract:

The increase in the number of terrorist attacks especially in the last few years

has shown that the effect of blast loads on buildings, doors and walls is a serious

matter that should be taken into consideration in the design process. The main

objective of this study is to shed light on blast resistant door design theories, the

enhancement of doors against the effect of explosives in both architectural and

structural process and the design techniques that should be carried out. Firstly

explosives and explosion types have been discussed briefly. In addition, the

general aspects of explosives process have been presented to clarify the effects

of explosives on blast doors. To have the better understanding of explosives will

enable us to make blast resistant doors much more efficiently. Essential

technique for increasing the capacity of door to provide protection against

explosives effect is discussed both with architectural and structural approach.

Keywords: Blast Doors, Design, Enhancement, Explosives, Explosives Effects,

TABLE OF CONTENTS

1. Organization profile Page No:

2. Introduction 1

3. Blast doors 2

4. Shock waves and Over pressure 3-7

5. Design of blast doors 7-11

6. Type of blast doors- 12-29

SO-1 type

SO-3 type

SO- double wing

SO-3 double wing

SO-6 double wing

7. Blast Hatch 30-34

Specification, Application, Design criteria

SL-1 hatch protective capability

Custom design protective doors

8. Blast door on the basis of position 34-41

Horizontal shelther doors

Vertical shelther door

Types on the based on Pensher

Series-1 aluminium blast resistance doors

Series-2 steel blast resistant doors

Series-2a steel blast resistant doors

Series-3b steel blast resistant doors

Series-4 steel security doors

9. Problem of 5A-7 design of doors for Pressure-time loading 42-50

Problem Procedure Required

10.Conclusion 51

11.Reference 52

List of Figures

Fig no:

1. Typical Blast door

2. Variation of pressure with distance

3. Formation of shock front in shock waves.

4. Variation of over pressure with distance

5. Variation of over pressure with at a given

6. Variation of over pressure with distance at a time

7. Variation of dynamic pressure with a distance at the

8. Door of light civil defence shelter in Finland.

9. SO-1 type door.

10. SO-2 type door.

11. SO-3 type door.

12. SO-6 type door.

13. SO-1 double wing door.

14. SO-3 double wing door.

15. Custom design protective door.

16. Horizontal shelter door.

17. Vertical shelter door.

18. Series-1 aluminium blast door.

19. Series-2 steel blast door.

20. Series-3A steel blast door.

21. Series-3B steel blast door.

22. Series-4 steel blast door.

23. door configuration and loading.

24. detail of composite angle /plate supporting element.

Organization profile:-

About DRDO

The Defence Research and Development Organisation (DRDO) is an agency

of the Republic of India, responsible for the development of technology for use

by the military, headquartered in New Delhi, India.

With a network of 52 laboratories, which are engaged in developing defence

technologies covering various fields, like aeronautics, armaments, electronics,

land combat engineering, life sciences, materials, missiles, and naval systems,

DRDO is India's largest and most diverse research organisation. The

organisation includes around 5,000 scientists belonging to the Defence Research

& Development Service (DRDS) and about 25,000 other scientific, technical

and supporting personnel.

History

Defence Research and Development Organisation (DRDO) was established in

1958 by amalgamating the Defence Science Organisation and some of the

technical development establishments. A separate Department of Defence

Research and Development was formed in 1980 which later on administered

DRDO and its 50 laboratories/establishments. Most of the time the Defence

Research Development Organisation was treated as if it was a vendor and the

Army Headquarters or the Air Headquarters were the customers. Because the

Army and the Air Force themselves did not have any design or construction

responsibility, they tended to treat the designer or Indian industry at par with

their corresponding designer in the world market. If they could get a MiG-21

from the world market, they wanted a MiG-21 from DRDO. DRDO started its

first major project in surface-to-air missiles (SAM) known as Project Indigo in

1960s. Indigo was discontinued in later years without achieving full success.

Project Indigo led to Project Devil, along with Project Valiant, to develop short-

range SAM and ICBM in the 1970s. Project Devil itself led to the later

development of the Prithvi missile under the Integrated Guided Missile

Development Programme (IGMDP) in the 1980s. IGMDP was an Indian

Ministry of Defence programme between the early 1980s and 2007 for the

development of a comprehensive range of missiles, including the Agni missile,

Prithvi ballistic missile, Akash missile, Trishul missile and Nag Missile. In

2010, then defence minister A K Antony ordered the restructuring of the

Defence Research and Development Organisation (DRDO) to give 'a major

boost to defence research in the country and to ensure effective participation of

the private sector in defence technology'. The key measures to make DRDO

effective in its functioning include the establishment of a Defence Technology

Commission with the defence minister as its chairman. The programmes which

were largely managed by DRDO have seen considerable success with many of

the systems seeing rapid deployment as well as yielding significant

technological benefits.DRDO has achieved many successes since its

establishment in developing other major systems and critical technologies such

as aircraft avionics, UAVs, small arms, artillery systems, EW Systems, tanks

and armoured vehicles, sonar systems, command and control systems and

missile systems.

Centre for Fire, Explosive and Environment Safety (CFEES)

The Centre for Fire, Explosive and Environment Safety (CFEES) is an

Indian defence laboratory of the Defence Research and Development

Organization (DRDO). Located in Timarpur, Delhi, its main function is the

development of technologies and products in the area of explosive, fire and

environmental safety. CFEES is organized under the Armaments Directorate of

DRDO. The present director of CFEES is Dr Chitra Rajagopal.

History

The Centre for Explosive and Environment Safety (CEES) was established in

1992 by merging three DRDO establishments; DRDO Computer Centre, Delhi,

The Directorate of Explosives Safety, DRDO HQ, and the Fire Adviser’s

Office, DRDO HQ. In 2000 another DRDO lab, “Defence Institute of Fire

Research (DIFR)” was merged with CEES. In order to emphasize the

importance of fire science, the Government renamed CEES as CFEES in 2003.

Areas of Work

CFEES works in the area of Explosive safety, Fire protection and environmental

safety. In addition to developing technologies to protect against these threats, it

also trains personnel in these areas, and enforces safety standards in the use of

hazardous materials- toxic, explosive and flammable. CFEES also designs and

develops sensors to detect these threats.

Explosive Safety

CFEES helps in the Siting of explosive processing and storage dumps and the

design, testing and evaluation of safe explosive storage houses. Additionally, it

trains armed forces personnel and DRDO scientists in the safe use of explosives

and ordnance, and enforces compliance of safety rules. Simulation and risk

modelling is also carried out, in order to aid in Disaster Management.

Environment Safety

CFEES develops treatment and disposal techniques for hazardous Heavy Metal

Wastes, as well as Photodegradable Polyethylene for use as packaging material

at high altitudes, which prevents the pollution in mountainous areas where the

Indian Army operates, such as Kargil and Siachen.

CFEES also plays an active role in formulating the phase-out strategy for halon

and other ozone layer threatening gases. The National Halon Management

Programme, funded under bilateral programme, is implemented by CFEES,

supported by Ozone Cell, India. Halons are one of the six categories of

chemicals that are covered under the phase-out programme of the Montreal

Protocol. The Montreal Protocol, to which India is a signatory, has called upon

the parties to phase out the CFCs, halons and other man-made ozone-depleting

chemicals. In this regard, the lab is researching into alternative chemicals for

fire suppression and other uses.

Fire Safety

CFEES is involved in the development of automatic fire and explosion

detection and suppression systems for armoured vehicles, and water mist based

fire protection Systems for various applications. It also develops lightweight fire

protection clothing. A smoke test tunnel for creating fire signatures under

various conditions has been installed.

Specialized Training for armed forces personnel in fire protection, safety,

prevention and firefighting is also conducted by CFEES. The lab has also

developed a software package for virtual firefighting and fire training

simulation.

Projects

Fire Detection and Suppression Systems

CFEES has successfully designed and operationalized Integrated Fire Detection

and Suppression Systems for Armoured vehicles like the Arjun MBT, T-72

"Ajeya" and AbhayICV.The system is based on infra-red detectors for the

detection of fire/explosion in the crew compartment, and is capable of

suppressing fuel-fire explosions resulting from an enemy hit or due to any

malfunction of the engine, transmission or electrical short circuit. The system is

capable of detection and suppression of fires in the crew compartment within

200 milliseconds and in the engine compartment within 15s.

Water Mist based Fire Protection

Water Mist based Fire Protection Systems have been developed. This includes

new nozzles for the generation of water mist, working at low pressure of 12 bars

and above to facilitate the proper atomization of water droplets under high

pressure. This system is used for the following applications:

IR signature suppression of plume emitted by exhaust of Naval

ships

Air cargo bay

Electronic cabinet fires

Fuel –air explosion suppressions

Intelligent Fire Sensor

CFEES has developed an Intelligent Fire Sensor with software based

on a fire signature database that allows its fire detection system to

accurately identify true fire situations in a few seconds while rejecting

false alarms. The sensor is a highly sensitive detection system coupled

with powerful intelligent analysis, which allows fire detection even in

dusty environment. The use of laser diode source and multiple

reflection increases the sensitivity of smoke detection.

The sensors sense the temperature and smoke, making the fire

detector sensitive to both slow-smouldering and fast-burning fires.

The system can be installed on board the ships, offshore machinery

rooms, aircraft cargo compartments, industries, chemical plants,

warehouses, etc. Production of this sensor is being carried out by

Southern Electronics Pvt. Ltd., a Bangalore based private

manufacturer.

Environment protection

Technology for the treatment and stabilization of Heavy metals (Pb, Cr,

Hg, Cd, Zn etc.) from effluents being generated by Ordnance Factories

and other manufacturing plants. The technology uses a cement/polymer-

based solid matrix, and is being license-produced by Quality Water

Management Systems Pvt. Ltd., Chennai.

Technology for removal of nitro bodies (HMX, RDX) from HMX plant

effluents (based on neutralization and alkaline hydrolysis).

CFEES has also built up expertise in the area of establishing ground

water monitoring networks for any project site.

CFEES has developed processes for producing Coal Pitch based

Activated Carbon Spheroids for adsorption of harmful chemical vapours

by the protective gears. This is used for protection against nuclear,

biological and chemical warfare. The powder has good mechanical

strength, low ash content and is eco-friendly.

A National Halon banking and management facility has been set up,

where impure halon can be purified to acceptable levels and stored.

Introduction

Damage to the assets, loss of life and social panic are factors that have to be

minimized if the threat of terrorist action cannot be stopped. Designing the

structures to be fully blast resistant is not an realistic and economical option,

however current engineering and architectural knowledge can enhance the new

and existing buildings to mitigate the effects of an explosion.

The main target of this study is to provide guidance to engineers and architects

where there is a necessity of protection against the explosions caused by

detonation of high explosives. The guidance describes measures for mitigating

the effects of explosions, therefore providing protection for human, structure

and the valuable equipment inside. The paper includes information about

explosives, blast loading parameters and enhancements for blast resistant door

design both with an architectural and structural approach. Only explosions

caused by high explosives (chemical reactions) are considered within the study.

High explosives are solid in form and are commonly termed condensed

explosives. TNT (trinitrotoluene) is the most widely known example.

In this paper, material tests were conducted to derive typical material models of

Steel (A588).The derived models were verified through the explicit analyses of

the foam panels by ANSYS. Performance of the panels with different scaled

distances was evaluated by blast tests. Numerical simulations considering the

parameters provided basic design guidelines for the protective structures with

sacrificial foam panels. Tests and simulations verified the proposed concept that

properly designed panels for the required blast loads can control the transmitted

pressure to the target structure under a certain pressure on the yield strength of

the Steel (A588).

1

BLAST DOORS

A blast Door is a place where people can go to protect themselves from bomb

blasts. It differs from a fallout shelter, in that its main purpose is to protect from

shock waves and overpressure, instead of from radioactive precipitation, as a

fallout shelter does. It is also possible for a shelter to protect from both blast and

fallout.

SHOCK WAVE AND OVER PRESSURE2

The sudden release of energy initiates a pressure wave in the surrounding

medium, known as a shock wave. When an explosion takes place, the expansion

of the hot gases produces a pressure wave in the surrounding air. As this wave

moves away from the centre of explosion, the inner part moves through the

region that was previously compressed and is now heated by the leading part of

the wave. As the pressure waves moves with the velocity of sound, the

temperature is about 3000o-4000oC and the pressure is nearly 300 kilobar of the

air causing this velocity to increase. The inner part of the wave starts to move

faster and gradually overtakes the leading part of the waves. After a short period

of time the pressure wave front becomes abrupt, thus forming a shock front

somewhat similar to.

The maximum overpressure occurs at the shock front and is called the peak

overpressure. Behind the shock front, the overpressure drops very rapidly to

about one-half the peak overpressure and remains almost uniform in the central

region of the explosion.

Variation of Pressure with Distance

3

Formation of Shock Front in Shock Wave

Variation of overpressure with distance from centre of explosion at various

times

An expansion proceeds, the overpressure in the shock front decreases steadily;

the pressure behind the front does not remain constant, but instead, fall off in a

regular manner. After a short time, at a certain distance from the centre of

explosion, the pressure behind the shock front becomes smaller than that of the

surrounding atmosphere and so called negative-phase or suction.

4

The front of the blast waves weakens as it progresses outward, and its velocity

drops towards the velocity of the sound in the undisturbedatmosphere. This

sequence of events is shown in Fig.3.1(c), the overpressure at time t1, t2…..t6

are indicated. In the curves marked t1 to t5, the pressure in the blast has not

fallen below that of the atmosphere. In the curve t6 at some distance behind the

shock front, the overpressure becomes negative.

The variation of overpressure with distance at a given time from centre of

explosion

5

Variation of overpressure with distance at a time from the explosion

Variation of dynamic pressure with distance at a time from the explosion

The time variation of the same blast wave at a given distance from the explosion

to indicate the time duration of the positive phase and also the time at the end of

the positive phase.Another quantity of the equivalent importance is the force

that is developed from the strong winds accompanying the blast wave known as

the dynamic pressure; this is

Proportional to the square of the wind velocity and the density of the air behind

the shock front. Its variation at a given distance from the explosion6

Mathematically the dynamic pressure pd expressed as.

Pd= ½ ρu2

Where u is the velocity of the air particle and ρ is the air density.

The peak dynamic pressure decreases with increasing distance from the centre

of explosion, but the rate of decrease is different from that of the peak

overpressure. At a given distance from the explosion, the time variation of the

dynamic Pd behind the shock front is somewhat similar to that of the

overpressure Ps, but the rate of decrease is usually different. For

design purposes, the negative phase of the overpressure in Fig.3.2 (b) is not

important and can be ignored.

DESIGNING OF BLAST DOOR

Blast door deflect the blast wave from nearby explosions to prevent ear and

internal injuries to people sheltering in the bunker. While frame buildings

collapse from as little as 3 psi (20 kPa) of overpressure, blast shelters are

regularly constructed to survive several hundred psi. This substantially

decreases the likelihood that a bomb can harm the structure.

The basic plan is to provide a structure that is very strong in compression. The

actual strength specification must be done individually, based on the nature and

probability of the threat. A typical specification for heavy civil defense shelter

in Europe during the Cold war was an overhead explosion of a 500 kiloton

weapon at the height of 500 meters. Such a weapon would be used to attack soft

targets (factories, administrative centers, and communications) in the area.7

http://en.wikipedia.org/wiki/Kilopascal

Only the heaviest bedrock-shelters would stand a chance of surviving. However,

in the countryside or in a suburb, the likely distance to the explosion is much

larger, as it is improbable that anyone would waste an expensive nuclear device

on such targets. The most common purpose-built structure is a steel-reinforced

concrete vault or arch buried or located in the basement of a house.

Most expedient blast shelters are civil engineering structures that contain large

buried tubes or pipes such as sewage or rapid transit tunnels. Even these,

nonetheless, require several additions to serve properly: blast doors, air-

filtration and ventilation equipment, secondary exits, and air-proofing.

Improvised purpose-built blast shelters normally use earthen arches or vaults.

To form these, a narrow (1-2 meter-wide) flexible tent of thin wood is placed in

a deep trench (usually the apex of the tent is below grade), and then covered

with cloth or plastic, and then covered with 1–2 meters of tamped earth.

Shelters of this type are approved field expedient blast shelters of both the U.S.

and China. Entrances are constructed from thick wooden frames. Blast valves

are to be constructed from tire-treads laid on thick wooden grids.

Nuclear bunkers must also cope with the under pressure that lasts for several

seconds after the shock wave passes, and prompt radiation. The overburden and

structure provide substantial radiation shielding, and the negative pressure is

usually only 1/3 of the overpressure.

The doors must be at least as strong as the walls. The usual design is a trap-

door, to minimize the size and expense. In dual-purpose shelters, which have a

secondary peace time use, the door may be normal. To reduce the weight, the

door is normally constructed of steel, with a fitted steel lintel and frame welded

to the steel-reinforcement of the concrete. The shelter should be located so that

there is no combustible material directly outside it.

8

If the door is on the surface and will be exposed to the blast wave, the edge of

the door is normally counter-sunk in the frame so that the blast wave or a

reflection cannot lift the edge. If possible, this should be avoided, and the door

built so that it is sheltered from the blast wave by other structures. The most

useful construction is to build the door behind a 90°-turn in a corridor that has

an exit for the overpressure.

Door of a light civil defence shelter in Finland

A bunker commonly has two doors, one of which is convenient, and in peace

time use, and the other is strong. Naturally, the shelter must always have a

secondary exit which can be used if the primary door is blocked by debris. Door

shafts may double as ventilation shafts to reduce the digging, although this is

unadvisable.

A large ground shock can move the walls of a bunker several centimeters in a

few milliseconds. Bunkers designed for large ground shocks must have sprung

internal buildings, hammocks, or bean-bag chairs to protect inhabitants from the

walls and floors. However, most civilian-built improvised shelters do not need

9

http://en.wikipedia.org/wiki/File:V%C3%A4est%C3%B6nsuojan_ovi.jpg

these as their structure cannot stand a shock large enough to seriously damage

the occupants.

Earth is an excellent insulator. In bunkers inhabited for prolonged periods, large

amounts of ventilation or air-conditioning must be provided to prevent heat

prostration. In bunkers designed for war-time use, manually operated ventilators

must be provided because supplies of electricity or gas are unreliable. The

simplest form of effective fan to cool a shelter is a wide, heavy frame with flaps

that swings in the shelter's doorway and can be swung from hinges on the

ceiling.

The flaps open in one direction and close in the other, pumping air. (This is a

Kearny Air Pump, or KAP, named after the inventor Cresson Kearny.) Kearney

asserts, based on field testing, that air filtration is not normally needed in a

nuclear shelter. He asserts that fallout is either large enough to fall to the

ground, or so fine that it will not settle and thus has little bulk to emit radiation.

However, if possible, shelters of soldiers have air-filtration to stop chemical,

biological and nuclear impurities which may abound after an explosion.

Ventilation openings in a bunker must be protected by blast valves. A blast

valve is closed by a shock wave, but otherwise remains open. If the bunker is in

a built-up area, it may include water-cooling or an immersion tub and breathing

tubes to protect inhabitants from fire storms. In these cases, the secondary exit

is also most useful.

Bunkers must also protect the inhabitants from normal weather, including rain,

summer heat and winter cold. A normal form of rain proofing is to place plastic

film on the bunker's main structure before burying it. Thick (5-mil or 125 µm),

inexpensive polyethylene film serves quite well, because the overburden

protects it from degradation by wind and sunlight. Naturally, a buried or

10

basement-situated reinforced-concrete shelter usually has the normal

appearance of a building.

When a house is purpose-built with a blast shelter, the normal location is a

reinforced below-grade bathroom with large cabinets. In apartment houses, the

shelter may double as storage space, as long as it can be swiftly emptied for its

primary use. A shelter can easily be added in a new basement construction by

taking an existing corner and adding two poured walls and a ceiling.

Some vendors provide true blast shelters engineered to provide good protection

to individual families at modest cost. One common design approach uses fiber-

reinforced plastic shells. Compressive protection may be provided by

inexpensive earth arching. The overburden is designed to shield from radiation.

To prevent the shelter from floating to the surface in high groundwater, some

designs have a skirt held-down with the overburden. A properly designed,

properly installed home shelter does not become a sinkhole in the lawn. In

Switzerland, which requires shelters for private apartment blocks and large

private houses, the lightest shelters are constructed of stainless steel.

11

TYPES OF BLAST DOOR :-

FROM TEMET

SO-1 type

Applications

The SO-1 blast doors are designed to stop the advance of blast waves through

the passage ways into the protected area of blast hardened Civl Defence and

military shelters. The SO-1 blast dors are possible to open and close manually

from both sides. The latching device tightens the door plate against the frame so

that the maximum clearance between the load bearing surfaces of the door plate

and the frame is 2.0 mm. Design of the door enables opening by disassembly

even if the door plate has undergone permanent deformations. The door plate

can be dismounted from either side without any special emergency opening

devices.

12

Specification

Manufacturer of SO-1 blast doors is Temet, Helsinki Finland.

The SO-1 blast doors are fabricated from structural steel with a door plate of

solid homogenous steel plate. The door fame is of flush design for easy

installation in the reinforced concrete wall, and the door plate / frame assembly

has an optimized pattern for transfer of the blast forces into the surrounding

wall.

Design Criteria

The SO-1 blast door is made in accordance with specific provisions issued by

the Finnish Ministry of Interior. The SO-1 blast doors are approved for use on

the basis of structural calculations approved by the Technical Research Centreof 13

Finland / VTT Building Technology, an Independent Testing Authority

mandated to perform type inspection for shelter equipment and systems by the

Ministry of Interior.

SO-1 Door Protection Capability

The SO-1 doors are designed and tested to withstand multiple long duration blast

loads having peak reflected overpressure of 2.0 bar in the elastic range of the

materials used. In rebound direction the doors resist negative blast forces

equivalent to 0.25 bar static pressure. The door fame design enables uniform

distribution of the positive blast load into the surrounding wall. Rebound load is

received by latching system and hinges.

14

The SO-1 doors also resist a mechanical shock transmitting through the installation

wall with a rapid change in velocity of 1.5 m/s corresponding to acceleration

force of 30 g. r

The doors are designed to function within the operating temperature range of -

20 …+80 ºC.

SO-3 type

Applications


the passage ways into the protected area of blast hardened Civil Defence and

military shelters. The SO-3 blast doors are possible to open and close manually

from both sides. The latching device tightens the door plate against the frame so

that the maximum clearance between the load bearing surfaces of the door plate

and the frame is 2.0 mm. Design of the doors enables opening by disassembly

even if the door plate has undergone permanent deformations. The door plate

can be dismounted from either side without any special emergency opening

devices.

15

Specification

Manufacturer of SO-3 blast doors is Temet, Helsinki Finland.

The SO-3 doors are fabricated from structural steel with a door plate of solid

homogenous steel plate. The door frame is of flush design for easy installations

in the reinforced concrete wall, and the door plate / frame assembly has an

optimized pattern for transfer of the blast forces into surrounding wall.

Design CriteriaThe SO-3 blast doors are made in accordance with specific provisions issued by


the basis of structural calculations approved by the Technical Research Centre

16

of Finland / VTT Building Technology, an Independent Testing Authority




The SO-3 doors are designed to withstand multiple long duration blast loads having

peak reflected overpressure of 8.0 bar within the elastic range of the materials

used. The resistance of the doors for rebound load is dependent on the basic

natural period of the door plate and varies between 0.8 bar and 4.0 bar

equivalent static pressure. The door fame design enables uniform distribution of

17

the positive blast load into the surrounding wall. Rebound load is received by

the latching system.

The SO-3 doors also resist a mechanical shock transmitting through the installation

wall with a rapid change in velocity of 1.5 m/s corresponding to acceleration

force of 30 g.

The SO-3 doors are designed to function within the operating temperature range

of -20 …+80 ºC.

SO-6 Type

Applications


the passage ways into the protected area of blast hardened Civil Defence and

military shelters. The SO-6 blast doors are possible to open and close manually

from both sides. The latching device tightens the door plate against the frame

so that the maximum clearance between the load bearing surfaces of the door

plate and the frame is 2.0 mm. Design of the doors enables opening by

disassembly even if the door plate has undergone permanent deformations.

The door plate can be dismounted from either side without any special

emergency opening devices

18

Specification

Manufacturer of SO-6 blast doors is Temet, Helsinki Finland. The SO-6 doors

are fabricated from structural steel with a door plate of solid homogenous steel

plate. The door frame is of flush design for easy installations in the reinforced

concrete wall, and the door plate / frame assembly has an optimized pattern for

transfer of the blast forces into surrounding wall.

Design Criteria

The SO-6 blast doors are made in accordance with specific provisions issued by




19




The SO-6 doors provide the highest level of protection against blast effects.

Their resistance against multiple long duration blast load ranges from 9.0 bar up

to 18 bar peak reflected overpressure. The SO-6 doors are designed to function

within the elastic range of the materials used. The resistance of the doors for

rebound load is dependent on the basic natural period of the door plate and

varies between 0.1 and 0.5 times the maximum positive blast load. The door

frame design enables uniform distribution of the positive blast load into the

surrounding wall. Rebound load is received by the latching system. The SO-6

doors also resist a mechanical shock transmitting through the installation wall 20

with a rapid change in velocity of 1.5 m/s corresponding to acceleration force of

30 g.

The SO-6 doors are designed to function within the operating temperature

range of -20 …+80 ºC.

SO-1 DOUBLE WING

Applications

The SO-1 double wing blast doors are designed to stop the advance of blast

waves through the passage ways into the protected area of blast hardened Civil

Defence and military shelters. The SO-1 blast doors are possible to open and

close manually from both sides. The latching device tightens the door plate

against the frame so that the maximum clearance between the load bearing

surfaces of the door plate and the frame is 2.0 mm. Design of the door enables

opening by disassembly even if the door plate has undergone permanent

deformations. The door plate can be dismounted from either side without any

special emergency opening devices.

21

Specification

Manufacturer of SO-1double wing blast doors is Temet, Helsinki Finland.

The SO-1double wing blast doors are fabricated from structural steel with a

door plate of solid homogenous steel plate stiffened by a structural steel centre

beam. The door fame is designed for easy installation into the reinforced

concrete wall, and the door plate / frame assembly has an optimized pattern for

transfer of the blast forces into the surrounding wall.

22

Design Criteria

The SO-1 blast door is made in accordance with specific provisions issued by






23


The SO-1 doors are designed and tested to withstand multiple long duration blast

loads having peak reflected overpressure of 2.0 bar in the elastic range of the

materials used. In rebound direction the doors resist negative blast forces

equivalent to 0.25 bar static pressure. The door fame design enables uniform


received by latching system and hinges.

The SO-1 doors also resist a mechanical shock transmitting through the

installation wall with a rapid change in velocity of 1.5 m/s corresponding to

acceleration force of 30 g. r

The doors are designed to function within the operating temperature range of -

20 …+80 ºC.

SO-3 DOUBLE WING

Applications






surfaces of the door plate and the frame is 2.0 mm. Design of the doors enables




24

Specification

Manufacturer of SO-3 blast doors is Temet, Helsinki Finland. The SO-3 double

wing blast doors are fabricated from structural steel with a door plate of solid

homogenous steel plate stiffened by a structural steel centre beam. The door

frame is designed for easy installations in the reinforced concrete wall, and the

door plate / frame assembly has an optimized pattern for transfer of the blast

forces into surrounding wall.

25

Design Criteria








The SO-3 doors are designed to withstand multiple long duration blast loads

having peak reflected overpressure of 8.0 bar within the elastic range of the 26

materials used. The resistance of the doors for rebound load is dependent on the

basic natural period of the door plate and varies between 0.8 bar and 4.0 bar

equivalent static pressure. The door frame design enables uniform distribution

of the positive blast load into the surrounding wall. Rebound load is received by

the latching system. The SO-3 doors also resist a mechanical shock transmitting

through the installation wall with a rapid change in velocity of 1.5 m/s

corresponding to acceleration force of 30 g.

The SO-3 doors are designed to function within the operating temperature range

of -20 …+80 ºC.

SO-6 DOUBLE WING

Applications






surfaces of the door plate and the frame is 2.0 mm. Design of the doors enables




27

Specification

The SO-6 double wing blast doors are fabricated from structural steel with a

door plate of solid homogenous steel plate stiffened by I-beams spanning

between the door sill and head. The door fame is designed for easy installation

in the reinforcedconcrete wall, and the door plate / frame assembly has an

optimized pattern for transfer of the blast forces into surrounding wall.

28

Design Criteria







29

BLAST HATCH

Applications

The SL-1 hatches are designed to stop the advance of blast waves into protected

area of Civil Defence and military shelters through the emergency exit passage

ways. The SL-1 hatches are possible to open and close manually from both

sides. The latching device tightens the hatch plate against the frame so that the

maximum clearance between the load bearing surfaces of the hatch plate and the

frame is 2.0 mm. Design of the hatch enables opening by disassembly even if

the hatch plate has undergone permanent deformations. The hatch plate can be

dismounted from either side without any special emergency opening devices.

30

Specification

Manufacturer of SL-1 hatches is Temet, Helsinki Finland. The SL-1 hatches are

fabricated from structural steel with a solid homogenous door plate. The hatch

frame is designed for easy installations in the reinforced concrete wall, and the

hatch plate / frame assembly has an optimized pattern for transfer of the blast

forces into surrounding wall

Design Criteria

The SL-1 hatch is made in accordance with specific provisions issued by the

Finnish Ministry of Interior. The SL-1 hatches are approved for use on the basis

of structural calculations approved by the Technical Research Centre of Finland

/ VTT Building Technology, an Independent Testing Authority mandated to

perform type inspection for shelter equipment and systems by the Ministry of

Interior.

31

SL-1 Hatch Protection Capability

The SL-1 hatches are designed and tested to withstand multiple long duration

blast loads having peak reflected overpressure of 2.0 bar in the elastic range of

the materials used. In rebound direction the hatch resist negative blast forces

equivalent to 0.25 bar static pressure. The door frame design enables uniform


received by latch and hinge systems. The SL-1 hatch also resists a mechanical

shock transmitting through the installation wall with a rapid change in velocity

of 1.5 m/s corresponding to acceleration force of 30 g.

The hatches are designed to function within the operating temperature range of -

20 …+80 ºC.

Custom designed protective doors

Temet custom designs protective doors in strict accordance with the client’s

specification. Typical structural custom requirements are design for short

duration impulsive blast load, high resistance for primary figment and air-

tightness at high pressure difference across the doors. Typical functional custom

requirements are power operation of the door and latching mechanism as well as

electrical door locking and connection to the door system interlocking.

32

Structural configuration of Temet custom doors may be steel door with

homogenous steel plate or I-beam stiffened steel plate structure. Concrete arch

doors are recommended for high pressure load for large door openings in

applications where the door jambs are capable of receiving the reaction forces

from the door arch. Sliding blast resistant and gas tight doors can be provided

for applications where space constraints prevent the use of swing doors.

Temet has over 20 years’ experience in supplying custom doors with extremely

demanding requirements. Projects successfully completed incorporate doors

with triangular bilinear impulse load up to 50 bar with 100 per cent

reboundresistance, combined blast resistant and air-tight doors providing zero

leakage up to 2000 Pa pressure difference across the door as well as very large

hinged concrete arch doors all having numerous additional functional

requirement.

33

Successful undertaking of a special door project implies that the door

manufactures capable of working together with the architect and structural

designer of the facility from the very beginning. This is imperative in order to

reserve sufficient space for the door and its embedded components and to

design the wall reinforcement properly to receive the substantial reaction forces

transmitted from the door. An important part of Temet’ services are the

capability to consult with the structural engineers on the issue of door interface

with the surrounding concrete structure.

ON THE BASIS OF POSITION

Horizontal Shelter Doors

The steel hatch is designed to be installed horizontally and surrounded with a

concrete collar. Opening and closing are assisted by spring-loaded shock

absorbers to prevent uncontrolled descent. The frame is 12 inches deep, with the

inside opening dimensions of 31” X 31”. The door leaf is 3/8 inches thick with a

1 ½” overlap all around the opening and is re-enforced with 3 inch square

tubing for stiffness. Hinges are hand made from ¾” steel plate and are mounted

internally to avoid damage from blast, flying debris, and vandals. The lock hasp

is removable from the inside for self-rescue

34

Because of its horizontal orientation to a blast wave and debris, this design

avoids reflected overpressure and direct insult from flying debris. (Doors of

vertical orientation must be made several times stronger to resist the reflected

overpressure they attract). An armored protective pocket is welded to the

outside of the leaf to protect the external lock from weapons effects and folks

with undesirable social skills. [Door leaf can be ordered in stainless steel to

prevent torching at greatly increased cost.] Weight: 600lbs.

Vertical Shelter Doors

For concrete shelters, the Swiss PT Armored Door series is an excellent choice.

These vertical configured doors are available in single-leaf and double-leaf

formats, and in several sizes. They are all designed to be cast into the wall

during construction (they cannot be bolted in later as a retro-fit). The door leaf

is approximately 8 inches thick with two curtains of re-enforcement rod welded

35

inside. The door/frame assembly must be cast into the concrete wall and

allowed to cure for two weeks. After the cure time has expired, a wooden frame

is placed over both sides of the leaf and the interior is then filled with concrete.

The door leaf may be opened and stripped after 3 days of cure.

The door leaf has concrete fill holes in both ends to permit right/left hand

placement. Be sure to block holes in the bottom of the door leaf before filling

with concrete. The supporting wall must have a minimum thickness of 10-

inches. Please allow 4 weeks shipping time to avoid impacting your

construction schedule. Blast protection rating: 3 bar [nuclear], 30 bar

[conventional HE ordnance]. These doors will defeat a 500lb. MK82 demolition

bomb exploding 12 feet away.

36

Types based on pensher

Series 1 Aluminium Blast Resistant Door

The Series 1 Aluminium Blast Resistant Door is designed and manufactured by

PensherSkyech to provide an Aluminium blast resistant door solution for

construction, civil engineering, aerospace, defence and petrochemical industries

– or any environment requiring a blast resistant door design and product.

Examples of applications for our Aluminium blast resistant door range include:

critical infrastructure sites, key assets, densely populated areas and buildings,

and environments or sites at potential risk of physical or natural attack.

37

Series 2 Steel Blast Door

The Series 2 Steel Blast Door is designed and manufactured by PensherSkytech

to provide a steel blast resistant door solution for construction, civil

engineering, aerospace, defence and petrochemical industries – or any

environment requiring a blast door design and product.

Applications for this steel blast door range can vary depending upon your

project specifications. In addition to blast, the Series 2 Steel Blast Door can be

adapted to incorporate fire resistant door and security door systems.

Examples of blast door applications include critical infrastructure sites, key

assets, densely populated areas and buildings, and environments or sites at

potential risk of physical or natural attack

38

Series 3a Steel Blast Resistant Door

The Series 3a Steel Blast Resistant Door is designed and manufactured by

PensherSkytech to provide a steel blast resistant door solution for construction,

civil-engineering, aerospace, defence and petrochemical industries – or any

environment requiring a blast resistant door design and product. The Series 3a

also has US DoS approval.

Applications for our high level steel blast resistant door range can vary based upon your project specifications. In addition to blast, the Series 3a can also incorporate a ballistic rating to be adapted into a bullet resistant door product.

39

Examples of applications include critical infrastructure sites, key assets, densely

populated areas and buildings, and environments or sites at potential risk of

physical or natural attack

Series 3b Steel Blast Resistant Door

The Series 3b Steel Blast Resistant Door is designed and manufactured by

PensherSkytech to provide a steel blast resistant door solution to construction,

civil engineering, aerospace, defence and petrochemical industries – or any

environment requiring a blast resistant door design and product.

Applications for our high level steel blast resistant door range can vary based

upon your project specifications. In addition to blast, the Series 3a can also

incorporate a fire door rating to be adapted into a fire resistant door product.

40

Examples of applications include critical infrastructure sites, key assets, densely

populated areas and buildings, and environments or sites at potential risk of

natural or physical attack.

Series 4 Steel Security Door

The Series 4 Steel Security Door is designed and manufactured by

PensherSkytech to provide a steel security door solution to construction, civil

engineering, aerospace, defence and petrochemical industries – or any

environment requiring a security door design and product.

Examples of applications for our steel security door range include: critical

infrastructure sites, key assets, environments or sites at potential risk of physical

attack.

PROBLEM 5A-7 DESIGN OF DOORS FOR PRESSURE-TIME LOADING

41

Problem: Design a steel-plate blast door subjected to a pressure-time

loading.

Procedure:

Step 1. Establish the design parameters.

a. Pressure-time load

b. Design criteria: Establish support rotation, Θmax, and whether seals

and rebound mechanisms are required

c. Structural configuration of the door including geometry and support

Conditions

d. Properties of steel used:1

Minimum yield strength, fy, for door components (Table 5-1)

Dynamic increase factor, c (Table 5-2)

Step 2. Select the thickness of the plate.

Step 3. Calculate the elastic section modulus, S, and the plastic section

modulus,

Z, of the plate.

Step 4. Calculate the design plastic moment, Mp, of the plate (Equation 5-7)

Step 5. Compute the ultimate dynamic shear, Vp(Equation 5-16)

Step 6. Calculate maximum support shear, V, using a dynamic load factor of

1.25

and determine V/Vp. If V/Vpis less than 0.67, use the plastic design

42

moment as computed in Step 4 (Section 5-31). If V/Vpis greater than 0.67,

use Equation 5-23 to calculate the effective Mp.

Step 7. Calculate the ultimate unit resistance of the section (Table 3-1), using

the

equivalent plastic moment as obtained in Step 4 and a dynamic load factor

of 1.25.

Step 8. Determine the moment of inertia of the plate section.

Step 9. Compute the equivalent elastic unit stiffness, KE, of the plate section.

(Table 3-8)

Step 10. Calculate the equivalent elastic deflection, XE, of the plate as given by

XE = ru/KE.

Step 11. Determine the load-mass factor KLM and compute the effective unit

mass,

me.

Step 12. Compute the natural period of vibration, TN.

Step 13. Determine the door plate response using the values of P/ruand T/TN

and

the response charts of Chapter 3. Determine Xm/XE and TE.

Step 14. Determine the support rotation,

tanΘ = (Xm) / (L/2)

Compare Θ with the design criteria of Step 1b.

43

Step 15. Determine the strain rate, ε, using Equation 5-1. Determine the

dynamic

increase factor using Figure 5-2 and compare with the DIF selected in

Step 1d.

If the criteria of Step 1 is not satisfied, repeat Steps 2 to 15 with a new

plate thickness.

Step 16. Design supporting flexural element considering composite action with

the

plate (if so constructed).

Step 17. Calculate elastic and plastic section moduli of the combined section.

Step 18. Follow the design procedure for a flexural element as described in

Section 5A-1.

EXAMPLE 5A-7 (A) DESIGN OF A BLAST DOOR FOR

PRESSURE-TIME LOADING

Required:

Design a double-leaf, built-up door (6 ft by 8 ft) for the given pressure-time

loading.

Step 1.Given:

a. Pressure-time loading (Figure 5A-7)

b. Design criteria: This door is to protect personnel from exterior

loading. Leakage into the structure is permitted but the maximum

end rotation of any member is limited to 2° since panic hardware

must be operable after an accidental explosion.

c. Structural configuration (Figure 5A-7)

Note:44

This type of door configuration is suitable for low-pressure range

applications.

d. Steel used: A36

figure

Figure 5A-7(a) Door Configuration and Loading, Example 5A-7(a)

Yield strength, fy= 42 ksi (Table 5-1)

Dynamic increase factor, c = 1.24 (Table 5-2)

Average yield strength increase factor, a = 1.1 (Section 5-12.1)

Hence, the dynamic design stress,

fds= 1.1 × 1.24 × 42 = 57.3 ksi (Equation 5-2)

and the dynamic yield stress in shear,

fdv= 0.55 fds= 0.55 × 57.3 = 31.5 ksi (Equation 5-4)

Step 2. Assume a plate thickness of 5/8 inch.

45

Step 3. Determine the elastic and plastic section moduli (per unit width).

S = (bd2/6) = [1× (5/8)2]/6 = 6.515 × 10-2 in3/in

Z = bd2/4= [1× (5/8)2]/4 = 9.765×10-2 in3/in

Step 4. Calculate the design plastic moment, Mp.

Mp= fds(S + Z)/2 = 57.3 [(6.515 × 10-2) (Equation 5-7)

+ (9.765 × 10-2)]/2 = 57.3 × 8.14 × 10-2 = 4.66 in-k/in

Step 5. Calculate the dynamic ultimate shear capacity, Vp, for a 1-inch width.

Vp= fdvAw= 31.5 × 1 × 5/8 = 19.7 kips/in (Equation 5-16)

Step 6. Evaluate the support shear and check the plate capacity. Assume

DLF = 1.25

V = DLF ×P ×L/2= (1.25×100×54×1)/2 = 3.375 kips/in

V/Vp= 3.375/19.7 = 0.171 < 0.67 (Section 5-31)

No reduction in equivalent plastic moment is necessary.

Note:

When actual DLF is determined, reconsider Step 6.

Step 7. Calculate the ultimate unit resistance, ru, (assuming the plate to be

simplysupportedat both ends).

ru = 8Mp/L2 = (8×4.16×103)/542 = 12.8 psi (Table 3-1)

Step 8. Compute the moment of inertia, I, for a 1-inch width.

I = bd3/12= 1×(5/8)3 = 0.02035 in4/in

Step 9. Calculate the equivalent elastic stiffness, KE.

KE = 384EI/5bl2 = (384×45×106×0.02035)/5×1×544 = 5.59 ksi/in46

Step 10. Determine the equivalent elastic deflection, XE.

XE = ru/KE = 12.8/5.59 = 2.28 inch

Step 11. Calculate the effective mass of element.

a. KLM (average elastic and plastic)

= (0.78 + 0.66)/2 = 0.72

b. Unit mass of element, m

c. m=w/g=228 psi-ms2/ in

c. Effective unit of mass of element, me

me= KLMm= 0.72 × 228.0

= 164 psi-ms2/in

Step 12. Calculate the natural period of vibration, TN.

TN = 2π (164/5.59)1/2 = 34 ms

Step 13. Determine the door response.

Peak overpressure P = 100 psi

Peak resistance ru= 12.8 psi

Duration T = 30 ms

Natural period of vibration TN = 34 ms

P/ru= 100/12.8 = 7.81

T/TN = 30/34 = 0.88

From Figure 3-64a of Chapter 3,

Xm/XE < 5

Since the response is elastic, determine the DLF from Figure 3-49 of

Chapter 3.

DLF = 1.35 for T/TN = 0.88

Step 14. Determine the support rotation.47

Xm = (1.35x100x2.28)/12.8 = 24.04 inch

tanΘ = Xm/(L/2) = 24.04/(54/2) = 0.89

Θ = 24° > 20° N.G.

Step 15. Evaluate the selection of the dynamic increase factor.

Since this is an elastic response, use Figure 3-49 (b) of Chapter 3 to

determinetm. For T/TN = 0.88, tm/T = 0.0.5 and tm = 15 ms. The strain rate

is:

Since the response is elastic,

ε= fds/EstEt (Equation 5-1)

Fds =57.3x[Xm/XE] = 57.3x[24.04/2.28] = 604.1 ksi

And tE= tm = 0.015 sec. Hence,

ε=604.1/45x0.015=0.894 in/in/sec

Using Figure 5-2, DIF = 1.31. The preliminary selection of DIF = 1.29 is

acceptable.

Since the rotation criterion is not satisfied, change the thickness of the

plate and repeat the procedure. Repeating these calculations, it can be

shown that a 3/4-inch plate satisfies the requirements.

Repeat:

Step 2. Assume a plate thickness of ¾ inch

Step 3. Determine the elastic and plastic section moduli (per unit width)

S= bd2/12= 1 x (3/4)2/12=9.37x10-2 in3/in

M=bd2/4= 1 x (3/4)2/4 =14.06x10-2 in3/in

Step 4. Calculate the design plastic moment, Mp

Mp=fds(S+Z)/2=57.3((9.37x10-2)+(14.06x10-2)/2=6.7 in-k/in

Step 5. Calculate the dynamic ultimate shear capacity, Vp for a 1- inch width

Vp=fdvAw=31.5x1x3/4=23.62 kips/in (Equation 5-16)

48

Step 6. Evaluate the support shear and check the plate capacity. Assume

DLF=1.25

V=DLF x P x L/2= 1.25 x 100 x 54 x 1/2 = 3.375 Kips/in

V/Vp=3.375/23.6= 0.67 (Section 5-31)

No reduction in equivalent plastic moment is necessary .

Note:

When actual DLF is determined, reconsider step 6.

Step 7. Calculate the ultimate unit resistance, ru, (assuming the plate to be

simply supported to both ends)

Ru=8Mp/I2 (Table 3-1)

8 x 6.77 x 103/542=18.41 psi

Step 10. Calculate moment of inertia I, for a 1 inch width

I=bd3/12=1 x (3/4)3/12= 0.0104 in4/in

Step 9. Calculate the equivalent elastic stiffness, KE

KE=384EI/5bl4

384 x 45 x 106 x 0.0104 / 5 x 546= 6.22 Ksi/in

Step 10. Determine the equivalent elastic deflection XE

XE= Ru/ KE= 18.41/5.92= 3.01 inch

Step 11. Calculate the effective mass of element.

KLM (average elastic and plastic)

=(0.78+0.66)/2=0.72

Unit mass of element, M

M= w/g=3 x 1 x 243 x 106/1728 x 32.2 x 12 x 4 = 272 psi-ms2/in

Effective unit of mass of element me,

Me= KLmM= 0.72 x 272.0=196.5 psi-ms2/in

Step 12. Calculate the natural period of vibration TN,

TN=2 x 3.14 x (196.5 / 4.22)1/2=42.9 ms

Step 13. Determine the door pressure

Peak overpressure P=10049

Peak resistance Ru=18.41 psi

Duration T= 30 ms

Natural period of vibration TN= 42.9 ms

P/Ru=100/18.41=5.43

T/TN=30/42.9=0.699

From the fig 3-64a of chapter 3,

Xm/XE<5

Since the response is elastic, determine the DLF from fig 3-49 of chapter 3.

DLF=1.20 for T/TN=0.699

Step 14. Determine support rotation.

Xm=1.20 x 100 x 3.02/18.41= 19.68 inch

TanΘ = Xm/(L/2) = 19.68/(54/2)= 0.728

Θ=20.050>200 N.G.

Step 15. . Evaluate the selection of the dynamic increase factor.

Since this is an elastic response, use Figure 3-49 (b) of Chapter 3 to

determinetm. For T/TN = 0.699, tm/T = 0.03 and tm = 9 ms. The strain rate

is:

Since the response is elastic,

ε= fds/EstEt (Equation 5-1)

Fds =57.3x[Xm/XE] =57.3 x 19.68/3.02= 373.40 ksi



ε = 373.40/45 x 103 x 0.009= 0.921 in/in/sec

Using fig 5-2, DLF=1.20

The primary selection of DLF= 1.25 is Acceptable

50

Conclusion

In this study the current status for the design of blast doors particularly for the

stainless steel (A588 grade b) profiled barrier is reviewed. The distinctive

response behaviour of various sections (plastic, compact and slander) has been

presented and some analysis tools for the assessment of the blast barrier has

been discussed. The study highlights several limitations inherent to single

degree of freedom method. Validation study on the design guidance given by

TN5 has also been discussed. Where the details study of blast door is required

the study is carried by finite element study. Some recommendations pertaining

to the numeric technique are given so the accurate response of blast door can be

obtained.

51

Reference:

[1] Koccaz Z. (2004) Blast Resistant Building Design, MSc Thesis, Istanbul

Technical University, Istanbul, Turkey.

[2] Yandzio E., Gough M. (1999). Protection of Buildings Against Explosions,

SCI Publication, Berkshire, U.K.

[3] Hill J.A., Courtney M.A. (1995). The structural Engineer’s Response to

Explosion Damage.The Institution of Structural Engineer’s Report, SETO Ltd,

London.

[4] Mays G.C., Smith P.D. (1995). Blast Effects on Buildings, Thomas Telford

Publications, Heron Quay, London.

[5] Hinman E. (2008) Blast Safety of the Building Envelope, WBDG, US

[6] MALO, K.A. and Ilstad, H. Response of corrugated steel doors due to

pressure loads

[7] Punch S. (1999) Blast Design of Steel Structures to Prevent Progressive

Collapse, Structural Engineers Association Convention Proceedings, Santa

Barbara, California, U.S.A.

[8] STEC-21, Defense research and development organization, Ministry Of

defense, India

[9] UFC- Unified Criteria Facilities 3-340-02

52