structural durability testing of commercial vehicles - …€¦ · -design criterion for...

Structural durability Structural durability testing of commercial testing of commercial

vehiclesvehicles

S. de Cock

Sept 2007

11. . the DAFthe DAF Service Conditions ProtocolService Conditions Protocol

1.11.1 IntroductionIntroduction

1.21.2 derivation of a durability specification, the DAF protocolderivation of a durability specification, the DAF protocol

1.31.3 The effect ofThe effect of component location and surface treatment.component location and surface treatment.

1.41.4 Derivation of design criteria for a componentDerivation of design criteria for a component

1.51.5 The derivation of a test specification forThe derivation of a test specification for whole vehicleswhole vehicles

1.61.6 CorrelationCorrelation of durability tests with service conditions.of durability tests with service conditions.

2.2. durability test methodsdurability test methods

3. Conclusions3. Conclusions

1.1 Introductiontrucks come in many shapes and sizes...

Vehicle:(> 15 ton, global data)

6 cabin types3 engine types * 4 power ratingsGear box ratios, final drive ratio16 axle configurationsChassis: 4 wheelbases, 3 choices of load capacity2 maximum axle load ratings per axle40 tire types30 fuel tanks15 component layouts

Further options:fifth wheel, side skirts, mudguards, spare wheel,bumper/front underrun protection, retarder, …

1.1 Introduction the customer decides what his vehicle is going to look like:

1.1 Introduction derivation of design criteria

A frequently used method:• Marketing defines a notoriously severe vehicle application.• Marketing chooses a typical customer.• The Testing group performs extensive measurements.• vehicle loads are extracted for design and testing purposes.• Start the design and testing activity.

• However,…….. The DAF method is different!

1.2 derivation of a durability specification1.2 derivation of a durability specificationthe DAF protocol:the DAF protocol:

Objective:To State a durability criterion

in terms of uniquely defined tests.The criterion should be formulated in such a manner,

that vehicles which meet it will fulfill all the customners' claimed and expected requirements;

this without any degree of over-design.⇓

The Service Conditions Protocol:Translates all types of use and associated loads

to standard test maneuvers ⇓

- Design criterion for durability- Test criterion for durability

.

1.2 Derivation of a durability specification: 1.2 Derivation of a durability specification: the service conditionsthe service conditions•• standard vehicle life:standard vehicle life: the distance a vehicle must be able to go the distance a vehicle must be able to go

without serious defects; 90% of all vehicles will achieve thiswithout serious defects; 90% of all vehicles will achieve this mileage. mileage.

•• Country of use.Country of use.

•• gross Vehicle Weight/payloadgross Vehicle Weight/payload

•• road surface qualityroad surface quality

•• Uphill gradient (particularly for the drive line).Uphill gradient (particularly for the drive line).

•• Vehicle speed pattern (city traffic, motorway).Vehicle speed pattern (city traffic, motorway).

•• maneuver loads (Cornering, braking).maneuver loads (Cornering, braking).

•• Climate.Climate.

1.2 Derivation of a durability specification:1.2 Derivation of a durability specification: the process the process

•• Market researchMarket research ⇒⇒ vehicle conceptvehicle concept ⇒⇒ service loads/standard lifeservice loads/standard life

•• Define at leastDefine at least 1 1 “vehicle application”“vehicle application” per per

vehicle configuration/ axle layout.vehicle configuration/ axle layout. This in terms of:This in terms of:

-- Nr. of kmsNr. of kms per per road surface typeroad surface type main structuremain structure

-- Nr. ofNr. of maneuvresmaneuvres forfor

-- road gradient pattern.road gradient pattern. drive linedrive line

•• translate each road surface type to one of the tracks at the testranslate each road surface type to one of the tracks at the test site. t site.

Each of these tracks is rated in terms of vehicle damage by meEach of these tracks is rated in terms of vehicle damage by means of ans of

an equivalence number. These numbers allow the expression of an equivalence number. These numbers allow the expression of

vehicle damage in terms of an equivalent mileage on one referevehicle damage in terms of an equivalent mileage on one reference track:nce track:

“equivalent“equivalent--pave kilometerspave kilometers””

1.2 The derivation of a durability specification: the process1.2 The derivation of a durability specification: the process

•• from all vehicle applicationsfrom all vehicle applications (~ (~ 800800) ) now select the criterion:now select the criterion:

thethe application which is more severe for the component than 95application which is more severe for the component than 95% % of theseof these..•• PerPer component component determine required life anddetermine required life and the maximum chance of failure :the maximum chance of failure :

-- Safety critical: Safety critical: x % failures @ 2 x life (90 % confidence)x % failures @ 2 x life (90 % confidence)-- impaired serviceability: y % failures @ 1 x life (90 % conf.) impaired serviceability: y % failures @ 1 x life (90 % conf.) -- other: other: z % failures @ 1 x life (50 % confidence).z % failures @ 1 x life (50 % confidence).

•• translate this into a test specificationtranslate this into a test specification (nr. of samples tested, level,(nr. of samples tested, level,

nr. of load cycles)nr. of load cycles) using the standard load spectrausing the standard load spectra..

All types of road surface and maneuvers available at the test siAll types of road surface and maneuvers available at the test site.te.

The DAF test site at St. OedenrodeThe DAF test site at St. Oedenrode

1.2 Vehicle application sheetsummary of the principal elements in the service conditions.

Type: FT 75 CF

land: France

standard life:

800 000 km, 7 years

application:

regional distribution

number sold per year:100

1. vehicle weight (ton)1. vehicle weight (ton)

From To FocusGV front 4 8 7GV rear 8 10 9,5GCW 14 44 38

Varies

2. road gradient pattern2. road gradient pattern

From To %Flat 0% 2% 70Hilly 2% 6% 20Mountains 6% 10% 10

Varies

3. vehicle speed pattern3. vehicle speed pattern

From To %Local roads 0 10 15City 10 40 15Inter city 40 70 30Long distance 70 100 40

Varies

5. road surface type5. road surface type

From To Average

Bitumous type 11 10% 15% 12%type 12 12% 20% 16%type 13 20% 40% 32%

Concrete type 21 0% 0% 0%type 22 0% 0% 0%type 23 0% 0% 0%

Clinckers type 31 0% 0% 0%type 32 0% 0% 0%type 33 0% 0% 0%

Pave type 41 0% 0% 0%type 42 0% 0% 0%type 43 0% 0% 0%

0% 0% 0%etc. type xx 0% 0% 0%

0% 0% 0%Ground type 101 0% 0% 0%

type 102 0% 0% 0%type 103 0% 0% 0%

Varies

there are some 800 vehicle applications !!

P rintda tum 29 -2 -0 0T ijd 15:5 7

V oertu igtoep assin g 9P P 1910 3D a tum va n o p ste llen 01 -0 3-0 0 eq u iv ale ntiefa cto ren g elde n d v oo r:

gro e p: vo e rtu ig (ge m idd e ld )T y pe F A D 9 5 X F 35 5 2 W e g de k k-fa cto r: 3 ,5 0O m s ch rijv in g K ipp e r w eg typ e eq . % v a n eq .V o ertu ig n orm le v en sd u ur k m 5 40 00 0 fo to om sc hr ijving fak tor vo er t.n lv d pa v e-k mV o ertu ig n orm le v en sd u ur jare n 7 1 .1 a s fa lt g oe d 0,0 00 8 80 ,0 36 0L an d Is ra el 1 .2 a s fa lt m atig 0,0 06 1 15 ,0 49 6V e rko o pa an ta l p er jaa r 20 0 (ja a r 19 99 ) 1 .3 a s fa lt s le c ht 0,0 5 0 ,0 0

2 .1 b e to n g o ed 0,0 02 1 0 ,0 0A s ty p e 13 55 T 2 .2 b e to n m a tig 0,0 03 3 0 ,0 0

2 .3 b e to n s lec ht 0,0 36 8 0 ,0 01 Vo e rtu ig g ew ich t [to n ] 3 .1 k lin ke rw e g g oe d 0,0 03 0 ,0 0

v ariee rt 3 .2 k lin ke rw e g m atig 0,0 2 0 ,0 0v an to t zw pt 3 .3 k lin ke rw e g s le c ht 0,2 0 ,0 0

a sla st vo o r 0 0 18 4 .1 p a ve go ed 0,0 4 0 ,0 0a sla st ac h te r 0 0 26 4 .2 p a ve m a tig 0,1 0 ,0 0G C W 63 4 .3 p a ve slec h t 1 0 ,0 0G VW 44 5 .1 s tee n slag go e d 0,0 1 1 ,0 5 4

5 .2 s tee n slag m a tig 0,0 5 2 ,0 54 03 H ellin g sp a tro o n 5 .3 s tee n slag sle ch t 0,5 1 ,0 2 70 0

v ariee rt 6 .1 g ra ve l g oe d 0,0 1 0 ,0 0v an to t zw pt 6 .2 g ra ve l m atig 0,0 5 0 ,0 0

v la k 0 0 60 6 .3 g ra ve l s le c ht 0,5 0 ,0 0h eu v elac h tig 0 0 38 6 .4 w a s bo rd g o ed 10 0 ,0 0b erg a ch tig 0 0 2 6 .5 w a s bo rd s lec h t 3 0 ,0 0

T o taa l 1 00 % 7 .1 h a rd z an d g o ed 0,0 2 0 ,0 07 .2 h a rd z an d m atig 0,1 0 ,0 0

4 Sn e lh eid s p atro o n 7 .3 h a rd z an d s lec ht 0,5 0 ,0 0v ariee rt 8 .1 d ro og za n d g oe d 0,0 1 0 ,0 0v an to t zw pt 8 .2 d ro og za n d m a tig 0,0 5 0 ,0 0

lok a al w erk v erk e er 0 0 3 8 .3 d ro og za n d s le ch t 0,5 0 ,0 0s tad sv e rke e r in te rn 0 0 5 9 .1 n a t z an d g o ed 0,0 1 0 ,0 0s tad sv e rk. d oo rg aa nd 0 0 10 9 .2 n a t z an d m a tig 0,0 5 0 ,0 0inte rste de lijk v er ke er 0 0 70 9 .3 n a t z an d s lec h t 0,5 0 ,0 0lan g e a fs tan d ve rk ee r 0 0 12 10 .1 te rre in go ed 0,0 1 0 ,0 0

T o taa l 1 00 % 10 .2 te rre in m a tig 0,0 5 0 ,0 0R a n g ee rfa kto r 1 5 b o ch ten pe r 1 00 0 k m 10 .3 te rre in slec h t 0,5 0 ,0 0S tro e fh eid 1 0 0 % T o taa l e q . p av e k m 4 14 9

9 95 K lim a at g ee n s p ec ifiek e in fo

6 O p m erk in g en 1 0% ov e rbe lad in gF A D om bo u w na a r F T D (k o pp els ch o te l)

V errichtingen per vo ertu igno rm levensduuro u d (1 99 5 ) va n af 20 0 0, z ie [1 ]

S n elle stu urbe w e ging e n L /R 1 48 32 0 7 4 16 00 b ela d ing s g ra ad (a ls fu n ctie va n g ere d en k m 's):L an g za m e stu urbe w e ging e n L /R (10 % S S )14 83 2 7 41 60B o ch ten lo k aa l w e rk ve rk ee r L/R 1 62 00 pe rc en ta ge le eg : 50 %R a n ge ren L /R 81 00 pe rc en ta ge vo l: 25 %S turen in sta nd L/R 8 10 pe rc en ta ge ov erbe la d en : 25 %R e m m in g en ('m e tho d ie k 2 00 0 ') 3 43 03 5 4 5 92 70 1 00 % (tota al)E q . h e uv ela ch tig m o tor k m 's 4 2 12 00

E q . S ta d/b erg a ch tig pig no n k m 's 8 14 54

vehicle vehicle application application sheetsheet

FAD FAD withwithstandard life:standard life:540.000 km540.000 km

V o e r tu ig to e p a s s in g 9 P P 1 9 1 0 3D a tu m v a n o p s te lle n 0 1 -0 3 -0 0

T y p e F A D 9 5 X F 3 5 5O m s c h r ijv in g K ip p e rV o e r tu ig n o rm le v e n s d u u r k m 5 4 0 0 0 0V o e r tu ig n o rm le v e n s d u u r ja re n 7L a n d Is ra e lV e rk o o p a a n ta l p e r ja a r 2 0 0 ( ja a r 1 9 9 9 )

A s ty p e 1 3 5 5 T

1 V o e rtu ig g e w ic h t [ to n ]v a rie e r t v a n to t z w p t

a s la s t v o o r 0 0 1 8a s la s t a c h te r 0 0 2 6G C W 6 3G V W 4 4

3 H e ll in g s p a tr o o nv a rie e r t v a n to t z w p t

v la k 0 0 6 0h e u v e la c h t ig 0 0 3 8b e rg a c h t ig 0 0 2

T o ta a l 1 0 0 %

4 S n e lh e id s p a tr o o nv a rie e r t v a n to t z w p t

lo k a a l w e rk v e rk e e r 0 0 3s ta d s v e rk e e r in te rn 0 0 5s ta d s v e rk . d o o rg a a n d 0 0 1 0in te rs te d e lijk v e rk e e r 0 0 7 0la n g e a fs ta n d v e rk e e r 0 0 1 2

T o ta a l 1 0 0 %



0.01 0.1 1 10 100 1000aantal wisselingen (genormeerd op 100 bochten)

0

0.1

0.2

0.3

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0.5

0.6

0.7

0.8

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oud/huidig bochten kollektief

nieuw bochtenkollektief

schadeinhoud nieuw kollektief t.o.v. oud remkollektief

k=3 k=5 k=7 k=9met v-grens 77% 34% 20% 15%zonder v-grens 88% 35% 20% 15%

Example: the load spectrum for corneringExample: the load spectrum for cornering

T otaa l 100 %R an g eerfa kto r 15 bo chten pe r 100 0 kmS tro e fh e id 1 00 %

5 K lim a at ge en spe c ifie ke in fo

6 O p m erkin g en 10 % ov erb e lad in gF A D om b ouw na ar F T D (kopp e lsch ote l)

Verrich ting en pe r vo ertu ig n orm leven sd u u rou d (19 95) va naf 200 0, z ie [1 ]

S n elle s tuurbew eg ing en L /R 148 320 741 600La ngz am e s tuurbe w eg in gen L /R (1 0% S S )14 832 74 160B o chten lok aa l w erkverkee r L /R 16 200R an geren L /R 8 100S turen in s tan d L /R 810R em m in gen ( 'm ethod iek 200 0 ') 343 035 459 270E q . he uve la ch tig m otor km 's 421 200

E q . S tad /b erg ach tig p ig no n km 's 81 454



e q uiva le ntie fa cto re n g e ld e nd vo o r:g roe p : v oe rtu ig (ge m idd e ld )

2 W eg de k k -fa cto r: 3 ,5 0w e gty pe e q . % va n e q .

fo to om sc hr ijv in g fa kto r vo e rt.n lvd p a ve -km1.1 a sfa lt g oe d 0 ,00 0 8 8 0 ,0 36 01.2 a sfa lt m a tig 0 ,00 6 1 1 5 ,0 49 61.3 a sfa lt s le c ht 0 ,05 0 ,0 02.1 b e ton g oe d 0 ,00 2 1 0 ,0 02.2 b e ton m atig 0 ,00 3 3 0 ,0 02.3 b e ton s le c ht 0 ,03 6 8 0 ,0 03.1 k lin ke rw e g g o ed 0 ,00 3 0 ,0 03.2 k lin ke rw e g m a tig 0 ,02 0 ,0 03.3 k lin ke rw e g s lec h t 0 ,2 0 ,0 04.1 p a ve go e d 0 ,04 0 ,0 04.2 p a ve m a tig 0 ,1 0 ,0 04.3 p a ve s le ch t 1 0 ,0 05.1 s tee n sla g go e d 0 ,01 1 ,0 5 45.2 s tee n sla g m a tig 0 ,05 2 ,0 54 05.3 s tee n sla g s le ch t 0 ,5 1 ,0 2 70 06.1 g rav el g o e d 0 ,01 0 ,0 06.2 g rav el m a tig 0 ,05 0 ,0 06.3 g rav el s le ch t 0 ,5 0 ,0 06.4 w a sb ord go e d 1 0 0 ,0 06.5 w a sb ord s le ch t 3 0 ,0 07.1 h a rd za n d g o e d 0 ,02 0 ,0 07.2 h a rd za n d m a tig 0 ,1 0 ,0 07.3 h a rd za n d s le ch t 0 ,5 0 ,0 08.1 d roo g za n d g o ed 0 ,01 0 ,0 08.2 d roo g za n d m atig 0 ,05 0 ,0 08.3 d roo g za n d s lec ht 0 ,5 0 ,0 09.1 n a t za nd g oe d 0 ,01 0 ,0 09.2 n a t za nd m atig 0 ,05 0 ,0 09.3 n a t za nd s le c ht 0 ,5 0 ,0 0

1 0.1 te rre in go e d 0 ,01 0 ,0 01 0.2 te rre in m a tig 0 ,05 0 ,0 01 0.3 te rre in s le ch t 0 ,5 0 ,0 0

T o ta a l e q. p av e k m 4 14 99 9

15% 15% moderatemoderate asphaltasphalt ==0.15 x 450.000 km = 81.000 km 0.15 x 450.000 km = 81.000 km ≅≅81.000 x 0.0061 = 496 km pave 81.000 x 0.0061 = 496 km pave eqeq..



• standard life (kms)• percentage full/empty• equivalent pave km• equivalent nr. of corners• equivalent nr. of slow

corners• equiv. nr. of brake

applications

9595--percentilepercentile

vehicle applicationvehicle application

Equivalent km’s paveEquivalent km’s pave

Equivalent km paveEquivalent km pave

% % of annual of annual vehicle salesvehicle sales

95 %CumulativeCumulative % % of vehicles soldof vehicles sold

Application sheet

……………..

…………..

……………..

…………..

1.2 Derivation of a test specification; determination of the 951.2 Derivation of a test specification; determination of the 95--percentile percentile vehicle application vehicle application via translationvia translation

into equivalent pavinto equivalent pave.e.

Durability test spec: Durability test spec: NN km equivalent km equivalent pave (test site)pave (test site)

1.2 derivation of a test specification1.2 derivation of a test specificationdetermination of the 95determination of the 95--percentile vehicle application percentile vehicle application via translation into via translation into equivalent pavequivalent pavéé..

1.31.3 The effect of componentThe effect of component locationlocation andand surface treatmentsurface treatment

OneOne single testsingle test requirement forrequirement for thethe whole vehiclewhole vehicle isis impossibleimpossible::

•• ForFor differentdifferent componentscomponents the mostthe most severesevere serviceservice conditionsconditions arearesometimes found onsometimes found on differentdifferent vehicle configurationsvehicle configurations//applicationsapplications..

•• Components mayComponents may havehave veryvery differentdifferent sensitivity tosensitivity to thethe variousvarioustypes oftypes of loading conditionsloading conditions ((cornering vscornering vs.. road excitationroad excitation).).

•• In the case ofIn the case of road excitationroad excitation: the: the equivalence numbersequivalence numbers,, which which representrepresent equivalentequivalent vehicle damagevehicle damage per kmper km for eachfor each type oftype of roadroadsurfacesurface,, alsoalso turn out differentturn out different for variousfor various componentcomponent locationslocations..

•• TheThe translationtranslation of theof the variousvarious serviceservice loadload spectraspectra to anto an equivalentequivalentnumbernumber ofof cyclescycles atat one load level leads toone load level leads to a differenta different result forresult fordifferent types ofdifferent types of material surfacematerial surface finish. (finish. (WöhlerWöhler constantconstant k).k).

Slope “Slope “--k”k”

The S-n curve: the average result of a large number of fatigue tests

The SN curveThe SN curveindicates indicates Fatigue lifeFatigue lifeas aas a functionfunction ofofload cycleload cyclemagnitude.magnitude.

1.31.3 TheThe influenceinfluence of componentof component locationlocation andand material surfacematerial surface((WöhlerWöhler constantconstant k)k)

N = c.Sa-k

'goed asfalt'

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

2 3 4 5 6 7 8 9k-factor

equi

vale

ntie

fact

or t.

o.v.

pav

e

1:Cabine2:Wieloph.3:Chassis4:Assen5:Comp.6:Motoroude w aarde

'slecht beton'

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

2 3 4 5 6 7 8 9k-factor

equi

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fact

or t.

o.v.

pav

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1:Cabine2:Wieloph.3:Chassis4:Assen5:Comp.6:Motoroude w aarde

The equivalence factors between track types at the test siteThe equivalence factors between track types at the test site

1.31.3 TheThe influenceinfluence of componentof component locationlocation andand material surfacematerial surface((WöhlerWöhler constantconstant k)k)

structural durability testing of commercial vehicles - …€¦ · -design criterion for...

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