MSC.Software Technology For Shipbuilders

Domenico Cacozza

Fabio Scannavino

MSC.Software Technology

MSC.Software provides the shipbuilding industry with virtual prototyping

solutions that ensure safety and reliability, compliance with requirements, and

make the ship design and verification process faster and more efficient.

Innovation and Risk Management

Application AreasMSC.Software solutions for the shipbuilding industry include:

• Modeling

• Static Linear Analysis

• Nonlinear Analysis

• Shaft & hull vibration

• Modal and Dynamic Analysis

• Strength & hull integrity

• Buckling analysis

• Fire loading

• Ship modeling automation

• Wave loading

• Underwater shock analysis

• Sloshing & ship dynamics

• Slamming

• Fatigue life prediction

• Acoustics & noise propagation

• Collision

• Optimization

• Electromagnetic

• Motion

• Rotor dynamics

• System & Controls

• On-board equipment modeling & analysis

• ……..

Static Linear Analysis

The template helps the users in the correct creation of the

model and in the generation of the documentation for the

certification.

Every section of the ship should be verified in hogging and sagging

condition

8 different load conditions:

caseAP

caseAM

caseBP

caseBM

caseCP

caseCM

caseDP

caseDM

Report with these results

- Displacements

- Equivalent Von Mises

- Component XX of stress

- Component YY of stress

- Component XY of stress

(8 load x 5 results) *2 view = 80 pictures

8 tables with key results

Ship modeling automation

Nonlinear Analysis

Manufacturing Process

7

Welding Analysis

Thermo-Mechanical Analysis

Composites Structures in Marine

● America’s Cup Yacht

● Overall weight 25t

● Ballast weight 20t (80%)

● Mast mass 330kg

● Boom mass 60kg

● Hull/deck mass 1700kg (of which 70% constrained by rule)

● Fin mass 1000kg (steel! Best modulus per unit volume)

● High performance

● Variable loading

● Benefits:

● Ply based model

● Automated generation

● Failure analysis

● Manufacturing link

● Optimization

COMPOSITE MATERIALS

LAMINATE

● Two or more materials combined on a

macroscopic scale, for example fibre

and resin

● Highly directional properties

● Highly variable properties, particularly

strength

2

3

1

WARP AND WEFT(FILL)● Warp fibers are aligned in the

direction of the roll of the

cloth(circumferential direction). They

tend to be straightest because of the

tension they are placed in.

Warp

fiber

Weft

fiber

• The real fibre direction could change up to 75 degrees

• A undevelopable surface (Double Curvature) is droppable because the fold can be cut

Draping Simulation

• Laminate effective material properties

are tailored to meet performance

requirements through the use of

lamination theory integrated in the

MSC.Software products.

Classical Lamination Theory (CLT)

= 0º, t=0.0125

= 45º, t=0.01

= 90º, t=0.01

= -45º, t=0.01

=0º, t=0.01

= -45º, t=0.0125

= 90º, t=0.0125

= 45º, t=0.0125

Composite Delamination

• Delamination can be caused by :– Manufacturing defects and stress

– Gradients near geometric discontinuities (like stiffener terminations and bolted joints)

• Delamination may result in local failure or even a significant loss of the structural

integrity

Composite Fracture Mechanics

Cohesive simulation

Sensitivity Analysisand Optimization

Geometry & FEA Results

Loading and Test (Lab) Results

Materials InformationDamage Distributions

Analysis Options

• Stress (total) Life

• Strain (initiation) Life

• Crack Propagation

• Vibration Fatigue

• Spot Weld Analyzer

• Software Strain Gauge

• Utilities

• Pre & Post

• Multi-axial Fatigue

Fatigue Life Contours

1500

-1500120

Strain (uE)

Time (seconds)

DISPLAY OF SIGNAL: TEST101.DAC

Strain Life

Plot605M30Sf': 857 b: -0.067 Ef': 0.636 c: -0.579

1E-3

1E-2

1E-1

Strain Amplitude

(M/M)

1E0 1E1 1E2 1E3 1E4 1E5 1E6 1E7 1E8

Life (Reversals)

1E3 1E4 1E5 1E61

2

3

4

5

6

7

Cross Plot of Data :

S61STRAIN1KT

Life(Miles)

Kt( )

0

1574.7 -750.4

808.70

4.8548

RangeuE

X-Axis

MeanuEY-Axis

DamageZ-Axis

DAMAGE HISTOGRAM DISTRIBUTION FOR : TRACK05.DHHMaximum height : 4.8548 Z Units : %

Fatigue Analysis

Multi Body Dynamics

Multi Body Dynamics

Dynamical Impact Analysis

Case Study: A study on Evaluation of Collision Strength for FPSO

The analysis of ship collision has attracted attention in order to

prevent a environment pollution.

Some of the ship collision accidents in the past remain instructive

records in losses of human lives and properties and

environmental damages.

The research activities of the ship collision have attended to

large oil carrier, LNG carrier, FPSO and so on that may cause

serious environmental pollution and in recent, some ship owners

have requested the collision evaluation for design.

Dynamical Shock Load Analysis

Response of Ships to Underwater Explosions

The response of structural panels subjected to

non-contact explosion is of vital importance in

the design of air crafts, marine vehicles such as

ships, submarines and steel off-shore towers.

Computational Fluid Dynamics

Helsinki-based WB-Sails

Helsinki-based WB-Sails was founded 30 years ago to manufacture sails for the

Olympic classes and small racing boats. During the past twenty years WB-Sails has

turned from a small backyard loft into a respectable sail maker. They have been

pioneering sail making CAD/CAM in the world and have been using CAE since 1979.

Fluid-Structure Interaction

Ship motion can often violent fluid motions in a partially filled tank and it may cause very high pressures which last for very short duration. These pressure may cause considerable damage to tank structure.

SLOSHING

Fluid-Structure Interaction

Case Study: HHIRoll motion

Pitch motion

Heavy Industry/Shipbuilding

Even though the sloshing pressures and flow velocities have been investigated forthe filling height 10% and 95%, the significant sloshing behavior has not been checked.

High pressure and velocity has occurred in tank roll excitation rather than pitch.

SLAMMING

Fluid-Structure Interaction

Acoustic Simulation

• Solve problems involving structures that

contact fluid, liquid or gas.

Noise on a Ship

• Low-frequency Noise

– Discretion (exterior noise):

• Propeller noise

• Hull radiation

• Muffler noise

• Etc.

– Crew comfort (interior noise):

• Diesel engine noise

• Turbulence noise

• Room-to-room insulation

• Etc.

• High-frequency Noise

– Sonar:

• Tonpilz transducer

• Sonar array

Propeller Fairing

• This case study shows propeller noise radiation in sea water and

the acoustic treatment effects on the rudders

• Lafayette Class Frigate from French Army

• The vicinity of the propeller is modelled

50 m 30 m

15 m

130 m16 m

• An admittance boundary

condition

– To model acoustic treatment on

the rudders

• Incident spinning duct modes

– To account for the real propeller

noise source

• a zero pressure BC on the

interface

– the air/water interface

• Infinite acoustic elements

– allows to compute for the far

field radiation

Key features

With a treatment on the

Rudders

• Virtual microphone are placed on an arc 40m far from the hull (in

infinite element domain)

Results – Pressure field

No treatment on the

Rudders

Directivity in the far field

The maximum noise is reduced by 3dB

The treatment modifies the directivity

3 m

Large Diesel Engine Noise

• This case study presents the radiation of a large ship engine

• This marine diesel engine has the following characteristics:

– 16V cylinders

– maximum regime: 1800 RPM

– Max Power 4320KW ( or 5900CV )

• The acoustic model is designed to reach 1000Hz (order 33 of RPM 1800)

Standard Computation Process

3. Post Processing and Analysis

FRF

s

Waterf

all

Maps Waterfall

1. Vibration computations 2. Acoustic computations

Import vibration

results

+ Restart Capability !!

3D Mesh Creation• There are many meshing tools on the market featuring fast 3D mesh

generation

• Wrapping functions will create for you a closed external surface

surrounding your structural model. This surface will carry the structural

information

• The 3D elements are easily generated with meshing tools

Non Reflecting

Surface

Structure model external

surface

3D acoustic

elements

Waterfall Diagram• Dedicated tool to post-process efficiently results on waterfall

diagrams

Watefall

map

SPL at fixed frequency,

varies with RPMSPL at fixed RPM,

varies with RPM

Results and Performance

• Results can be retrieved anywhere both in the finite element and in

the infinite element (beyond the non reflecting surface) with the

same high accuracy

• The acoustic power radiated by the engine can also be computed

Thanks to the fast solver

implemented into Actran, the CPU

time is around 4 min per frequency !

(RAM consumption around 1GB)

Modeling

MSC.Software 49 years in Simulation for Engineering

Multi Body DynamicsDynamic Impact

& Shock Analysis

From Design …

… To Product

MSC.Software

Virtual Product Development

Solution Thermal loads

& heat transfer

Vibration

& acoustics

Stresses &

Fatigue

THANK YOU !!!