road restraint systems - extrudakerb

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BRITISH STANDARD BS EN1317-1:1998

The European Standard EN 1317-1:1998 has the status of aBritish Standard

ICS 01.040.13; 01.040.93; 13.200; 93.080.30

NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW

Road restraint systems

Part 1: Terminology and general criteriafor test methods

Licensed copy:Arup, 27/04/2010, Uncontrolled Copy, © BSI

This British Standard, havingbeen prepared under thedirection of the Sector Board forBuilding and Civil Engineering,was published under theauthority of the Standards Boardand comes into effect on15 September 1998

BSI 1998

ISBN 0 580 30103 6

BS EN 1317-1:1998

Amendments issued since publication

Amd. No. Date Text affected

National foreword

This British Standard is the English language version of EN 1317-1:1998.

The UK participation in its preparation was entrusted by Technical CommitteeB/509, Road equipment, to Subcommittee B/509/1, Road restraint systems, which hasthe responsibility to:

Ð aid enquirers to understand the text;

Ð present to the responsible European committee any enquiries on theinterpretation, or proposals for change, and keep the UK interests informed;

Ð monitor related international and European developments and promulgatethem in the UK.

A list of organizations represented on this committee can be obtained on request toits secretary.

This Part of BS EN 1317, together with Part 2 and the proposed Parts 3, 4 and 5, willcollectively eventually supersede BS 6779 which will then be withdrawn. This isexpected to take place by the end of 2000.

Cross-references

The British Standards which implement international or European publicationsreferred to in this document may be found in the BSI Standards Catalogue under thesection entitled ªInternational Standards Correspondence Indexº, or by using theªFindº facility of the BSI Standards Electronic Catalogue.

A British Standard does not purport to include all the necessary provisions of acontract. Users of British Standards are responsible for their correct application.

Compliance with a British Standard does not of itself confer immunityfrom legal obligations.

Summary of pages

This document comprises a front cover, an inside front cover, the EN title page,pages 2 to 19 and a back cover.


CENEuropean Committee for Standardization

ComiteÂ EuropeÂen de Normalisation

EuropaÈisches Komitee fuÈ r Normung

Central Secretariat: rue de Stassart 36, B-1050 Brussels

1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN nationalMembers.

Ref. No. EN 1317-1:1998 E

EUROPEAN STANDARD EN 1317-1

NORME EUROPEÂ ENNE

EUROPAÈ ISCHE NORM April 1998

ICS 01.040.93; 13.200; 93.080.30

Descriptors: road safety, pavements: roads, roads, safety devices, crash barriers, definitions, specifications, tests, impact tests

English version

Road restraint systems Ð

Part 1: Terminology and general criteria for test methods

Dispositifs de retenue routiers ÐPartie 1: Terminologie et dispositions geÂneÂrales pourles meÂthodes d'essais

RuÈckhaltesysteme an Straûen ÐTeil 1: Terminologie und allgemeine Kriterien fuÈrPruÈfverfahren

This European Standard was approved by CEN on 5 March 1998.

CEN members are bound to comply with the CEN/CENELEC Internal Regulationswhich stipulate the conditions for giving this European Standard the status of anational standard without any alteration. Up-to-date lists and bibliographicalreferences concerning such national standards may be obtained on application tothe Central Secretariat or to any CEN member.

This European Standard exists in three official versions (English, French, German).A version in any other language made by translation under the responsibility of aCEN member into its own language and notified to the Central Secretariat has thesame status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland andUnited Kingdom.


EN 1317-1:1998

BSI 1998

Foreword

This European Standard has been prepared by theTechnical Committee CEN/TC 226, Road equipment,the Secretariat of which is held by AFNOR.

This European Standard consists of the following partsunder the general title Road restraint systems.

Part 1: Terminology and general criteria for testmethods;

Part 2: Performance classes, impact test acceptancecriteria and test methods for safety barriers;

Part 3: Crash cushions Ð Performance classes, impacttest acceptance criteria and test methods for crashcushions;

The following parts are not yet available but are in thecourse of preparation:

Part 4: Impact tests acceptance criteria and testmethods for terminals and transitions of safetybarriers;

Part 5: Durability criteria and evaluation ofconformity;

Part 6: Pedestrian road restraint system.

This European Standard shall be given the status of anational standard, either by publication of an identicaltext or by endorsement, at the latest by October 1998,and conflicting national standards shall be withdrawnat the latest by October 1998.

According to the CEN/CENELEC Internal Regulations,the national standards organizations of the followingcountries are bound to implement this EuropeanStandard: Austria, Belgium, Czech Republic, Denmark,Finland, France, Germany, Greece, Iceland, Ireland,Italy, Luxembourg, Netherlands, Norway, Portugal,Spain, Sweden, Switzerland and the United Kingdom.

Contents

Page

Foreword 2

Introduction 3

1 Scope 3

2 Normative references 3

3 Abbreviations 3

4 Road restraint system terminology 3

5 Vehicle specifications under test conditions 5

6 Measurement of the acceleration severityindex (ASI) 6

7 Measurement of the theoretical head impactvelocity (THIV) and post-impact headdeceleration (PHD) 7

8 Compensation for instrumentation displacedfrom the vehicle centre of gravity 10

9 Test report 11

Annex A (normative) Vehicle cockpit deformationindex (VCDI) 13

Annex B (informative) Impact kinetic energy andtheoretical average force 14

Annex C (informative) Vehicle acceleration ÐMeasurement and calculation methods 15


EN 1317-1:1998

BSI 1998

Figure 1 Ð Types of systems

IntroductionIn order to improve and maintain highway safety, thedesign of safer roads requires the installation, oncertain sections of road and at particular locations, ofdevices to restrain vehicles and pedestrians fromentering dangerous zones or areas. The road restraintsystems designated in this standard are designed tospecified performance levels of containment, toredirect errant vehicles and to provide guidance forpedestrians or other road users.

The objective of this standard is to provide aprocedure whereby the present national standards andregulations, which currently pertain in membercountries, can be harmonized to a common EuropeanStandard.

Many types of road restraint systems are available;their characteristics differ both by function and byon-road use. European standardization requirescommon terminology in order to provide a clearunderstanding of the design, performance, productionand construction of the various road restraint systems.

This standard identifies impact test tolerances andvehicle behaviour criteria that need to be met to gainapproval. The design specification, for road restraintsystems entered in the test report, should identify theon-road site conditions under which the road restraintsystem should be installed.

The performance range of restraint systems, designatedin this standard, enables national and local authoritiesto recognize and specify the performance class to bedeployed.

The range of possible vehicular impact into an on-roadroad restraint system is extremely large in terms ofspeed, approach angle, vehicle type, vehicleperformance, and other vehicle and road conditions.Consequently the actual on-road impacts which occurmay vary considerably from the specific standard testconditions. However, adequate implementation of thestandard should identify the characteristics, in acandidate safety road restraint system, that are likelyto achieve maximum safety and reject those featureswhich are unacceptable.

It is recommended that this standard is reviewedwithin a period of five years, or following thecompletion of a proposed set of impact validationtests.

1 ScopeThis European Standard gives the definitions of theprincipal terms used for road vehicle restraint systemsand pedestrian restraint systems in other parts of thisstandard. It also specifies the general provisions fortest methods.Informative annexes B and C give information onimpact kinetic energy and vehicle acceleration.

2 Normative referencesThis European Standard incorporates by dated orundated reference, provisions from other publications.These normative references are cited at theappropriate places in the text and the publications arelisted hereafter. For dated references, subsequentamendments to or revisions of any of thesepublications apply to this European Standard onlywhen incorporated in it by amendment or revision. Forundated references the latest edition of the publicationreferred to applies.EN 1317-2, Road restraint systems ÐPart 2: Performance classes, impact test acceptancecriteria and test methods for safety barriers.prEN 1317-3, Road restraint systems ÐPart 3: Performance classes, impact test acceptancecriteria and test methods for crash cushions.

3 Abbreviations

ASI: Acceleration severity indexTHIV: Theoretical head impact velocityPHD: Post-impact head decelerationOIV: Occupant impact velocityORA: Occupant ridedown accelerationVCDI: Vehicle cockpit deformation indexVIDI: Vehicle interior deformation index

4 Road restraint system terminologyThe types of systems are shown in Figure 1.


EN 1317-1:1998

BSI 1998

For the purposes of this standard, the followingdefinitions apply:

4.1

road restraint system

general name for vehicle restraint system andpedestrian restraint system used on the road

4.2

vehicle restraint system

system installed on the road to provide a level ofcontainment for an errant vehicle

4.3

safety barrier

road vehicle restraint system installed alongside, or onthe central reserve, of a road

4.4

permanent safety barrier

safety barrier installed permanently on the road

4.5

temporary safety barrier

safety barrier which is readily removable and used atroad works, emergencies or similar situations

4.6

deformable safety barrier

safety barrier that deforms during a vehicle impact andmay suffer permanent deformation

4.7

rigid safety barrier

safety barrier that has negligible deflection during avehicle impact

4.8

single-sided safety barrier

safety barrier designed to be impacted on one sideonly

4.9

double-sided safety barrier

safety barrier designed to be impacted on both sides

4.10

terminal

the end treatment of a safety barrier

4.11

leading terminal

terminal placed at the upstream end of a safety barrier

4.12

trailing terminal

terminal placed at the downstream end of a safetybarrier

4.13

transition

connection of two safety barriers of different designsand/or performances

4.14

vehicle parapet

safety barrier installed on the edge of a bridge or on aretaining wall or similar structure where there is avertical drop, and which may include additionalprotection and restraint for pedestrians and other roadusers

4.15

crash cushion

road vehicle energy absorption device installed in frontof a rigid object to reduce the severity of impact

4.16

redirective crash cushion

crash cushion designed to contain and redirect animpacting vehicle

4.17

non-redirective crash cushion

crash cushion designed to contain and capture animpacting vehicle

4.18

arrester bed

area of land adjacent to the road filled with aparticular material to decelerate and arrest errantvehicles

4.19

pedestrian restraint system

system installed to restrain and to provide guidance forpedestrians

4.20

pedestrian parapet

pedestrian or ªother usersº restraint system along abridge or on top of a retaining wall or similar structurewhich is not intended to act as a road vehicle restraintsystem

4.21

pedestrian guardrail

pedestrian or ªother userº restraint system along theedge of a footway or footpath intended to restrainpedestrians and other users from stepping onto orcrossing a road or other area likely to be hazardous

NOTE. ªOther usersº includes provision for equestrians, cyclistsand cattle.


EN 1317-1:1998

BSI 1998

Table 1 Ð Vehicle specifications

Mass

kg

Vehicle mass (1) 825 ± 40 1 300± 65

1 500± 75

10 000± 300

13 000± 400

16 000± 500

30 000± 900

38 000± 1 100

Including maximumballast (2)

100 160 180 Ð Ð Ð Ð Ð

Dummy 75 Ð Ð Ð Ð Ð Ð Ð

Total test mass 900 ± 40 1 300± 65

1 500± 75

10 000± 300

13 000± 400

16 000± 500

30 000± 900

38 000± 1 100

Dimensions

m

(limit deviation ±15%)

Wheel track (front andrear)

1,35 1,40 1,50 2,00 2,00 2,00 2,00 2,00

Wheel radius (unloaded) Ð Ð Ð 0,46 0,52 0,52 0,55 0,55

Wheel base (betweenextreme axles)

Ð Ð Ð 4,60 6,50 5,90 6,70 11,25

Number of axles 1S+ 1 (3)

1S + 1 1S + 1 1S + 1 1S + 1 1S + 1/2 2S + 2 1S + 3/4

Ground clearance of thefront bumper measured atthe corner

Ð Ð Ð 0,58 Ð 0,58 0,58 0,58

Centre of gravitylocation

m

(limit deviation ±10 %)

Longitudinal distance (4)from front axle (CGX)±10 %

0,90 1,10 1,24 2,70 3,80 3,10 4,14 6,20

Lateral distance fromvehicle centre line (CGY)

±0,07 ±0,07 ±0,08 ±0,10 ±0,10 ±0,10 ±0,10 ±0,10

Height above ground(CGZ):

Vehicle mass (±10 %) 0,49 0,53 0,53 Ð Ð Ð Ð Ð

Load (+15 % 25 %) Ð Ð Ð 1,50 1,40 1,60 1,90 1,90

Type of vehicle Car Car Car RigidHGV

Bus RigidHGV

Rigid ArticulatedHGV

(1) Including load for heavy goods vehicles (HGV).

(2) Including measuring and recording equipment.

(3) S: steering axle.

(4) Vehicle mass.

5 Vehicle specifications under testconditionsVehicle specifications under test conditions arespecified in Table 1.


EN 1317-1:1998

BSI 1998

6 Measurement of the accelerationseverity index (ASI)

6.1 Calculation of ASI

The acceleration severity index ASI is a function oftime, computed using the following equation (1):

ASI(t) = (ax/aÃx)2 + (ay/aÃy)2 + (az/aÃz)2¯

(1) where:

aÃx, aÃy and aÃz are limit values for the components ofthe acceleration along the body axes x, y and z; ax, ayand az are the components of the acceleration of aselected point P of the vehicle, averaged over a movingtime interval d = 50 ms, so that:

ax = ax dt;1

d⌠⌡t

t + d

ay = ay dt;1

d⌠⌡t

t + d

az = az dt. (2)1

d⌠⌡t

t + d

The index ASI is intended to give a measure of theseverity of the vehicle motion for a person seated inthe proximity of point P during an impact.

The average in equation (2) is actually a low pass filter,taking into account the fact that vehicle accelerationscan be transmitted to the occupant body throughrelatively soft contacts, which cannot pass the highestfrequencies.

Equation (1) is the simplest possible interactionequation of three variables x, y and z. If any twocomponents of vehicle acceleration are null, ASIreaches its limit value of 1 when the third componentreaches its limit acceleration, but when two or threecomponents are non-null, ASI may be 1 with the singlecomponents well below the relevant limits.

The limit accelerations are interpreted as the valuesbelow which passenger risk is very small (light injuriesif any).

For passengers wearing safety belts, the generally usedlimit accelerations are:

aÃx = 12g, aÃy = 9g, aÃz = 10g (3)where:

g = 9,81 ms22 is the reference for the acceleration.

With equation (1), ASI is a non-dimensional quantityand a scalar function of time, and, in general at theselected vehicle point, having only positive values. Themore ASI exceeds unity, the more the risk for theoccupant in that point exceeds the safety limits;therefore the maximum value attained by ASI in acollision is assumed as a single measure of the severity,or:

ASI = max. [ASI(t)] (4)

6.2 Vehicle instrumentation

Vehicle acceleration shall be measured at a single point(P) within the vehicle body close to the vehicle centreof gravity. Three acceleration transducers (or onetri-axial transducer) are then required.

Experience, however, shows that, due to physicalconstraints, the actual placement of the set ofaccelerometers may be offset several centimetres fromthe centre of gravity; then, significant differences canoccur between measured accelerations and those atthe centre of mass, due to angular motions. In thesecases a second tri-axial transducer set ofaccelerometers shall be placed along the longitudinalaxis.

In long vehicles acceleration can vary considerablyfrom the front to the rear, mainly due to yaw motion.For example, in a bus colliding with a side barrier, it isrecommended to evaluate ASI at two points (P1 andP2), corresponding to the extreme forward andbackward passenger positions: the most direct way todo this is to place two tri-axial transducers in suchpositions.

Alternatively, if a complete set of transducers isinstalled to record the six degrees of freedom motionof the vehicle, the complete vehicle acceleration fieldcan be computed, and then the ASI index can be easilyevaluated at any point.

The transducers, filters and recording channels shallcomply with the frequency class specified inEN 1317-2 and prEN 1317-3.

6.3 Summary of the procedure to compute ASI

a) Record the measures of the three components ofvehicle acceleration with the prescribedinstrumentation. In general such measures are storedon a magnetic support, as three series of N numbers,sampled at a certain sampling rate S (samples persecond).

For such three series of measures:1ax, 2ax,...., k-1ax, kax, k+1ax,...., Nax1ay, 2ay,...., k21ay, kay, k+1ay,...., Nay1az,...., k21az, kaz, k+1az,..., Naz

the acceleration of gravity g is the unit ofmeasurement.

b) Find the number m of samples in the averagingwindow d = 0,05 s:

m = INT(d*S) = INT(0,05*S), where INT(R) is theinteger nearest to R. For example, if S = 500 samples/s,m = 25.


EN 1317-1:1998

BSI 1998

c) Compute the average accelerations (2):

kax =1

m

(5)=jax(kax + k+1ax + k+2ax +...+ k+max) 1

m∑

j = k

k + m

kay =1

m

(6)=jay(kay + k+1ay + k+2ay +...+ k+may) 1

m∑

j = k

k + m

kaz =1

m

(7)=jaz(kaz + k+1az + k+2az+...+ k+maz) 1

m∑

j = k

k + m

d) Compute ASI as a function of time (1):

kASI = (8)¯

2 + 2 + 2(kax/12) (kay/9) (kaz/10) e) Find ASI as the maximum of the series of kASI.

7 Measurement of the theoretical headimpact velocity (THIV) and post-impacthead deceleration (PHD)

7.1 General

The theoretical head impact velocity (THIV) concepthas been developed for assessing occupant impactseverity for vehicles involved in collisions with roadvehicle restraint systems. The occupant is consideredto be a freely moving object (head) that, as the vehiclechanges its speed during contact with the vehiclerestraint system, continues moving until it strikes asurface within the interior of the vehicle. Themagnitude of the velocity of the theoretical headimpact is considered to be a measure of the vehicle tovehicle restraint system impact severity.

The head is presumed to remain in contact with thesurface during the remainder of the impact period. Inso doing it experiences the same levels of accelerationas the vehicle during the remaining contact period(post-impact head deceleration Ð PHD).

7.2 Theoretical head impact velocity (THIV)

7.2.1 General

It can be assumed that at the beginning of the contactof the vehicle with the restraint system, both thevehicle and the theoretical head have the samehorizontal velocity V0, vehicle motion being purelytranslational.

During impact the vehicle is assumed to move only ina horizontal plane, because high levels of pitch, roll orvertical motion are not of prime importance unless thevehicle overturns. This extreme event does not need tobe considered, as in this case the decision to reject thecandidate system will be taken on the basis of visualobservation or photographic recording.

Two reference frames are used, as indicated inFigure 2:

Ð a vehicle reference Cxy, x being longitudinal andy transversal; the origin C is a point of the vehicleclose to, but not necessarily coincident with thecentre of gravity, where two accelerometers and ayaw rate sensor are installed. Let xÈ c and yÈ c be theaccelerations of point C (in m/s2), respectively alongthe vehicle axis x and y, recorded from the twoaccelerometers, and cÇ the rate of yaw (in radiansper second), recorded from the sensor (xÈ positiveforward, yÈ positive to right-hand side and cÇ positiveclockwise looking from above);

Ð a ground reference 0XY, horizontal, with the Xaxis aligned with the velocity V0 and the origin 0coinciding with the initial position of the vehicledatum point C. Xc(t), Yc(t) are the groundco-ordinates of the vehicle reference C, while Xb(t),Yb(t) are the ground co-ordinates of the theoreticalhead (see Figure 3).

With the definitions and the simplifying hypothesis ofthis paragraph, the vehicle and theoretical head motionshall be computed in accordance with 7.2.2 to 7.2.6.


EN 1317-1:1998

BSI 1998

Figure 2 Ð Vehicle and ground reference frames

7.2.2 Vehicle motion

Initial conditions at time t = 0:

Xc = 0 Yc = 0 c = c0

XÇ c = V0 YÇ c = 0 cÇ = 0 (9)

The yaw angle c shall be measured from the recordingof a suitable overhead camera, or it shall be computedby integration of the yaw rate cÇ or other suitablemeans:

c(t) = cÇ dt + c0 (10)⌠⌡0

t

then, from the components of vehicle acceleration inground reference:

XÈ c = xÈ c cos y2 yÈ c sin c

YÈ c = xÈ c sin y + yÈ c cos c (11)

vehicle velocity and position are computed byintegration:

XÇ c = DXÇ c + V0 DXÇ c = XÈ c dt⌠⌡0

t

YÇ c = DYÇ c DYÇc = YÈc dt⌠⌡0

t (12)

Xc= DXÇ c dt + V0t⌠⌡0

t

YÇc= DYÇc dt⌠⌡0

t

(13)


EN 1317-1:1998

BSI 1998

7.2.3 Theoretical head motion relative to ground

Initial condition at time t = 0:

Xb = x0 cos c = X0 Yb = xb sin ψ = Y0

XÇ b = V0 YÇ b = 0 (14)

Then, if the theoretical head continues its uniformmotion:

Xb = V0t + X0, Yb = Y0 (15)

7.2.4 Theoretical head motion relative to vehicle

The vehicle components of the relative velocity of thetheoretical head are:

Vx(t) =2DXÇ c cos c 2 DYÇc sin c + ybcÇ

Vy(t) = DXÇ c sin c2DYÇ c cos c2 xbcÇ (16)

The co-ordinates of the theoretical head with respectto the reference frame can be computed from thefollowing equation:

xb(t) = DXb cos c +DYb sin c DXb = X02 D dt⌠⌡0

t

XÇ

where

yb(t) =2DXb sin c +DYb cos c DYb = Y02 DYÇ dt⌠⌡0

t

(17)

7.2.5 Time of flight

The notional impact surfaces inside the vehicle areassumed to be flat and perpendicular to the vehicle xand y axes (see Figure 3). The distances of suchsurfaces from the original head position (flaildistances) are Dx forward and Dy laterally on bothsides.

Figure 3 Ð Impact of the theoreticalhead on the left side

The time of flight of the theoretical head is the time ofimpact on one of the three notional surfaces inFigure 3, i.e. the shortest time T when one of the threefollowing equalities is satisfied:

xb (T) = Dx + x0; or

yb (T) = Dy; or

yb (T) = 2Dy (18)The standard values of the flail distances are:

Dx = 0,6 m;

Dy = 0,3 m.


EN 1317-1:1998

BSI 1998

(*) 1g = 9,81 m22.

7.2.6 Value of THIV

Finally, the theoretical head impact velocity is therelative velocity at time T, i.e.:

THIV (19)¯V (T) + V (T) x2

y2

THIV shall be reported in km/h.

7.3 Post-impact head deceleration

Post-impact head deceleration (PHD) is the maximum

value of the resultant acceleration of point C,

computed from the 10 ms average of the measuredcomponents xÈ c and yÈ c. If xÈ c and yÈ c are such

components, then:

(20)

PHD shall be reported in multiples of g(*).

7.4 Vehicle instrumentation

The vehicle should be fitted with one accelerometerfor measurement in the longitudinal (forward)direction, one for the lateral (sideways) direction and,optionally, an angular velocity sensor (rate sensor). Thethree sensors should be mounted on a common blockand placed at point C close to the vehicle centre ofgravity.

The yaw angle shall be measured within a toleranceof ±48, directly from photographic records or byintegration of yaw rate or by other means. Thesampling interval shall not exceed 50 ms.

The transducers, filters and recording channels shallcomply with the frequency class specified inEN 1317-2 and prEN 1317-3.

An event indicator is recommended to signal themoment of first vehicle contact with the vehiclerestraint system.

7.5 Summary of the procedure to compute THIVand PHD

a) Record the vehicle accelerations and yaw rate,and store in digital form at the sample rate S; let thedata in the three record files be kxÈ c, kyÈ c and kc(k = 1, 2,..., N). The time interval between twosubsequent data in the record file is h = kt 2 k-1t= 1/S. For example, if S = 500 samples/s, h = 2 ms.

b) Interpolate linearly between the measured valuesof the yaw angle to obtain the values kc, oralternatively, integrate the yaw rate by the recurrentequation [from equation (2)]:

1c = c0; 2c = 1c + h ; ... ;1cÇ + 2cÇ

2

k+1c = kc + h (21)kcÇ + k+1cÇ

2

c) Compute the vehicle acceleration in groundreference (3):

kXÈ c = kxÈccos kc 2 kyÈ c sin kckYÈc = kxÈ csin kc + kyÈc cos kc (22)

d) Integrate the vehicle acceleration in groundreference equations (4), (9):

1D c = 0;X´ k+1DXÇ c = kD c + hX

´ kXÈ c + k+1XÈ c2

1D c = 0;Y´ k+1DYÇc = kDYÇ c + h

kYÈc + k+1YÈc

2(23)

1DXb = X0; k+1DXc = kDXc2 hkDXÇ c + k+1DXÇ c

2

1DYc = 0; k+1DYc = kDYc2 hkD c + k+1D cY

´Y´

2(24)

e) Compute relative position and relative velocity ofthe theoretical head as functions of time, equations(8), (9):

kxb(t) = kDXb cos kc + kDYb sin kckyb(t) = 2kDXb sin kc + kDYb cos kc (25)

kVx = 2kD c cos kc 2kD c sin kc + kYbkcÇXÇ YÇ

kVy = kDXÇ c sin kc 2 kDYÇc cos kc 2 kxbkcÇ (26)

f) Find the minimum value of j for which one of thethree equations:

jxb = Dx + X0; or jyb = Dy; or jyb =2Dy (27)is satisfied.

g) Compute:

THIV = jV¯

(28) + jVx2

y2

h)Compute the 10 ms average kxÈc

and kyÈc

.

i) Compute the resultant vehicle acceleration (kA)

in g as a function of time:

(29)

7.6 Procedure for computing OIV and ORA

The above procedure can be simplified to compute theoccupant impact velocity (OIV) and the occupantridedown acceleration (ORA), by omitting step 2 andconsidering always c = 0.

8 Compensation for instrumentationdisplaced from the vehicle centre ofgravityVehicular accelerations are used in the assessment oftest results through ASI, THIV and the flail spacemodel.


EN 1317-1:1998

BSI 1998

Figure 4 Ð Positive sign convention and accelerometer location

1) This proposal is based upon the criteria presented in paragraph 5.4.3 of the European Standard EN 45001:1998.

This requires that a set of accelerometers should beplaced at or close to the vehicle centre of mass.However, experience shows that this cannot always bedone, due to physical constraints within the vehicle. Asa result, actual placement of the set of accelerometersmay be offset several centimetres from the centre ofgravity, then, depending on the offset, significantdifferences can occur between measured accelerationsand those at the centre of gravity, due to angularmotions.These differences can be minimized by the use ofadditional instrumentation. Therefore, in addition tothe basic tri-axial set of accelerometers, it isrecommended that a second tri-axial set be placedalong the x (longitudinal) axis, as shown in Figure 2.With reference to Figure 4, for a point P located alongthe x axis at a distance x forward from the centre ofgravity:

ax = axc 2 x v( + vy2

z2)

ay = ayc 2 xvÇ z (30)az = azc 2 xvÇ y

where:

ax, ay, az are the longitudinal, lateral and verticalaccelerations of point P;

axc, ayc, azc are the longitudinal, lateral and verticalaccelerations of the centre of gravity;

vÇ y, vÇ z are the pitch and yaw rates;vÇ y, vÇ z are the pitch and yaw accelerations.

Thus, the accelerations of points P1 and P2 ofFigure 4 are given by:

ax1 = axc 2 x1 (v + vy2

z2)

ax2 = axc 2 x2 v + v( y2

z2)

ay1 = ayc + x1vÇ zay2 = ayc + x2vÇ z (31)

az1 = azc + x1vÇ y

az2 = azc + x2vÇ yFrom equation (2) the accelerations of the centre ofgravity can be computed as follows:

axc =x1ax2 2 x2ax1

x1 2 x2

ayc = (32)x1ay2 2 x2ay1

x1 2 x2

azc =x1az2 2 x2az1

x1 2 x2

9 Test report1)

The test report shall include the following informationin the order given.

a) Testing laboratory

Name

Address

Telephone number

Facsimile number

Test site location

b) Report number

c) Client

Name

Address

Telephone number

Facsimile number

d) Test item

Received date

Tested date

Name of test item

Drawing enclosure No.


EN 1317-1:1998

BSI 1998

*) The asterisk indicates optional information.

e) Test procedure

1) Test type

Target impact speed in kilometres per hour

Target impact angle in degrees

Target inertial vehicle test mass in kilograms

2) Installation

Detailed description of installation tested

Test site drawing enclosure No., including endanchorages

Photographs enclosure No.

Length in metres

A suitable description of the components of thevehicle restraint system for a guardrail consistingof post and beams:

Ð Beam rail member

Ð Beam rail length in metres

Ð Post material

Ð Post dimensions in metres

Ð Post embedment in metres

Ð Post spacing in metres

Soil type and condition

3) Vehicle

Model

Model year

Vehicle identification number (VIN)

Vehicle mass in kilograms

Ballast, position and mass

Dummy (if fitted)

Total test mass in kilograms

Dimensions and characteristics of vehicleenclosure No.

Position of centre of gravity

Photographs enclosure

f) Results

Test No.

Date

Weather conditions at test

General description of test sequence

1) Test item

Maximum dynamic deflection in metres

Working width in metres

Maximum permanent deflection in metres

Length of contact in metres

Impact point

Major parts fractured or detached (Yes/No)

Description of damage to test item

Ground fixing meets design levels (Yes/No/Notapplicable)

Photographs of test item enclosure

Drawing of test item enclosure*) Barrier ground fixing force measurement innewtons*) Force graphs enclosure

2) Vehicle

Impact speed in kilometres per hour

% difference from target speed in per cent

Impact angle in degrees

% difference from target angle in degrees

Within tolerance limits (Yes/No)*) Exit speed in kilometres per hour*) Exit angle in degrees*) Rebound distance in metres

Vehicle breaches barrier (Yes/No)

Vehicle passes over the barrier (Yes/No)

Vehicle within ªboxº (Yes/No)

Vehicle rolls over within test area (Yes/No)

General description of vehicle trajectory

Vehicle cockpit deformation index VCDI (seeannex A)

Major part of vehicle detached (Yes/No)

Photographs of the vehicle enclosure No.

3) Assessment of the impact severity

Acceleration severity index, ASI

Theoretical head impact velocity, THIV andpost-impact head deceleration, PHD

Flail space in metres

Time of flight in milliseconds

THIV in kilometres per hour

PHD in g*) Occupant impact velocity, OIV

Forward in metres per second

Lateral in metres per second

Occupant ridedown acceleration

Forward in g

Lateral in g

Acceleration graphs enclosure No.

g) General statements

The test results in this report relate only to theitems tested.

This report may not be reproduced other than infull, except with the prior written approval of theissuing laboratory.

h) Approval of report

Date

Signature

Title

Name


EN 1317-1:1998

BSI 1998

All seats: XX = AS

Front seats: XX = FS Back seats: XX = BS

Right seats: XX = RS Left seats: XX = LS

Right front: XX = RF Right back: XX = RB

Left front: XX = LF Left back: XX = LB

Figure A.1 Ð Location of cockpit deformation

Annex A (normative)

Vehicle cockpit deformation index (VCDI)

A.1 Deformation

The vehicle cockpit deformation index (VCDI) comesfrom the vehicle interior deformation index (VIDI),which has been developed within the frame ofdifferent international meetings in 1970 and 1971.

This index designates both the location and the extentof the deformation of the cockpit. It consists of twoalphabetic characters plus seven numeric characters, inthe form:

XXabcdefgThe purpose of this index is to report a standarddescription of the deformation of vehicle interior, tohelp the understanding of the severity of the impact.

The recommended accuracy in distance measurementsis ±0,02 m.

A.2 Location of the deformation

The location of cockpit deformation is indicated by thefirst two alphabetic characters XX, as indicated inFigure A.1.

A.3 Extent of the deformation

The seven sub-indices a, b, c, d, e, f and g indicate thepercentage of reduction of seven interior dimensions(see Figure A.2): The value of each of the sevennumeric sub-indices shall be determined by thefollowing scale:

0 if the reduction is less than 3 % ;

1 if the reduction is more than 3 % and less than orequal to 10 % ;

2 if the reduction is more than 10 %.

When some of the reductions exceed 10 %,photographic description of the deformed parts shallbe included.


EN 1317-1:1998

BSI 1998

a distance between the dashboard and the top of the rear seat;

b distance between the roof and the floor panel;

c distance between the rear seat and the motor panel;

d distance between the lower dashboard and the floor panel;

e interior width;

f distance between the lower edge of the right window and the upper edge of the left window;

g distance between the lower edge of left window and the upper edge of right window.

Figure A.2 Ð Interior dimensions

Figure B.1 Ð Displacement of the centre of gravity

A.4 Examples

When a side impact on the right side reduces e and fby 14 % and g by 7 % for the right seats, the reductionof all the remaining dimensions being below 3 %, theVCDI index will be: RS0000221.

When, in an end-on impact, distance a is reducedby 8 % and c by 12 % at the front right seat, all otherreductions remaining below 3 %, the VCDI index willbe: RF1020000.

Annex B (informative)

Impact kinetic energy and theoreticalaverage force

B.1 Average force from kinematics

In the first part of a successful collision against asafety barrier, the component, perpendicular to thebarrier, of the velocity of the centre of gravity of thevehicle should decrease from its initial value

Vn = V sin a (B.1)to null; if Sn and an are, respectively, the displacementand the average acceleration of the vehicle centre ofgravity in the direction perpendicular to the barrier,then in the first phase:

an = (B.2)Vn

2

2Snand, accordingly, the average force acting on the massM of the vehicle during the same phase is:

F = Man = (B.3)MVn

2

2Sn


EN 1317-1:1998

BSI 1998

Table B.1 Ð Containment levels

Containmentlevel

Kineticenergy

Traffic face deflection

kJ m

0,1 0,4 0,8 1,2 1,6 2,0

Average force F

kN

T1 6,2 16,8 9,3 5,8 4,2 3,3 2,7

T2 21,5 36,5 24,2 16,7 12,7 10,3 8,6

T3 36,6 46,7 33,8 24,7 19,4 16,0 13,6

N1 43,3 59,2 42,0 30,3 23,7 19,4 16,5

N2 81,9 112,0 79,4 57,2 44,7 36,7 31,1

H1 126,6 93,6 76,6 61,7 51,6 44,4 38,9

H2 287,5 133,0 116,8 100,4 88,1 78,5 70,8

H3 462,1 266,4 227,1 189,8 163,0 142,9 127,1

H4a 572,0 311,3 267,6 225,4 194,7 171,4 153,1

H4b 724,6 269,1 242,1 213,6 191,1 172,8 157,8

B.2 Average force from an energy balance

The same result can be obtained from a simple energybalance. In fact during the first phase of the impact thelateral kinetic energy of the vehicle:

T = (B.4)MVn2

2should be balanced by the work Wn = FSn of the lateralforce acting on the vehicle centre of gravity; hence:

= FSn

MVn2

2whence:

F = (B.5)MVn

2

2Sn

B.3 Average force as a function of barrierdisplacement

With reference to Figure B.1, the space Sn travelled bythe centre of mass is approximately:

Sn = c sin a + b(cos a2 1) + Sb (B.6)where Sb is the maximum dynamic deflection of thetraffic face of the barrier (more precisely, Sb should bethe sum of the barrier deflection plus a part of thevehicle crumpling).

Thus, combining the preceding expressions the averageforce can be eventually expressed as:

F = (B.7)M(V sin a)2

2[c sina + b(cos a2 1) + Sb]

The force F gives the order of magnitude of theinteraction between the vehicle and the barrier duringthe impact. It is useful for a first evaluation of the totalforce acting on barrier anchorages and of the severityfor the colliding vehicle.

F is a force averaged with respect to lateraldisplacement, i.e.:

F = F(s)ds (B.8)1

Sn

⌠⌡0

Sn

Theoretical and experimental evidence shows that asignificant maximum value of the force F(s), to beconsidered as a measure of the maximum action onbarrier anchorages, is 2,5 times larger than F.

B.4 Examples

Table B.1 reports the kinetic energies, computed usingequation B.4 pertaining to the specified performanceclasses, together with the average forces computedusing equation B.7 for some example values of barrierdisplacement.

Annex C (informative)

Vehicle acceleration Ð Measurement andcalculation methods

C.1 Introduction

During an impact the acceleration of a vehicle mayvary sensibly from one point to another of the vehicleitself due to angular velocities and angularaccelerations. Therefore, the measure taken at a singlepoint may not be enough to determine the completeacceleration field within the vehicle.

In general, during a collision there is an internalportion of the vehicle that remains more or less rigid,apart from structural vibrations which are filtered outwhen the prescribed 60 Hz filter is applied.


EN 1317-1:1998

BSI 1998

This annex presents two methods for determining thecomplete acceleration of the vehicle, considered as arigid body, at a certain time, from measures taken atthe same time. The sensors for these measures shouldbe mounted in locally stiff points of the part of vehiclestructure that behaves rigidly.

The knowledge of the complete acceleration may beneeded for computing the acceleration of differentpoints of the vehicle, or to reconstruct the vehicle pathby integration.

C.2 Acceleration in a rigid body

The acceleration pa of any point P of a rigid body, invector notation, may be expressed as:

pa =ca + v 3 R + v 3 (v 3 R) (C.1)

where:

pax

pa ≡ pay is the acceleration of the generic point P;

paz

cax

ca ≡ cay is the acceleration of a datum point C;

caz

vx

v ≡ vy is the angular velocity of the rigid body;

vz

R = P2C is the radius vector from point C to point P;Alternatively, equation (C.1) can be also put in theform:

pa = ca + vÇ ∧ R + (v´R) v 2 (v´v)R (C.2)

where the point represents scalar product, the dot (´)represents derivation with respect to time and thesymbol ∧ the vector product.

Then to know the acceleration pa of any point P of arigid body at a certain time t, one needs to know theposition R of the said point and nine kinematicparameters, i.e. the three components of ca, the threecomponents of v and the three components of vÇ , allat the same time t.

C.3 Measurement by 12 linear transducers

Equation (C.1), in matrix notation, can be also writtenas:

(C.3)= + [A]{pa} {ca} {R}

where:

2v 2 vy2

z2 vxvy + vÇ z vxvz + vÇ y

[A] = vxvy + vÇ z 2v 2 vx2

z2 vyvz2vÇ x

vxvz2vÇ y vyvz + vÇ x 2v 2 vÇx2

y2

Instead of the nine kinematic parameters it may beeasier to take as unknowns 12 parameters, i.e. thethree components of ca and all the nine elements ofmatrix A, as follows.

Three linear accelerometers, aligned with the vehicleaxes x, y and z, are mounted on a single block atpoint C (which can be any suitable point), and ineach of three other suitable points 1P, 2P and 3P. Thefour points should not lie in the same plane.These 12 accelerometers give the measure of {ca} plusthe accelerations {1a}, {2a} and {3a}, of the threeknown points 1P, 2P and 3P.

For each point iP, equation (C.4) can be put in theform:

(C.5)= [A] ,{iDa} {iR} (i = 1, 2, 3)

where:

(C.6)= 2{iDa} {ia} {ca}

By introducing the matrices (33 3):

(C.7)= , =[Da] [1Da|2Da|3Da] [R] [1R|2R|3R]

the three matrix equations (C.6) can be syntheticallywritten as:

(C.8)=[Da] [A][R]that can be easily solved obtaining the unknownmatrix [A] in the form:

T (C.9)= 21, or T = R 2T[A] [Da][R] [A] [ ] [DA]

Solution (C.9) is possible only if matrix [R] isnon-singular, and this requires that the four points

cP, 1P, 2P and 3P do not lie in a plane.

The angular acceleration vÇ can be easily obtainedfrom the antisymmetrical part of matrix [A]:

0 2vÇ x vÇ y

[A] 2 [A]T =1

2

1

2vÇ z 0 2vÇ x

(C.10)

2vÇ y vÇ x 0

However, the components of the angular velocitycannot be obtained uniquely nor accurately from thesymmetrical part of matrix [A]. So this method, whichis very straightforward for computing the accelerationof any point of the vehicle, is not recommended forpath reconstruction.

When the acceleration {ca} and the matrix [A] areknown, the acceleration of any point P of the vehiclecan be easily determined by means of equation (C.3).

C.4 Measurement by six linear and threeangular transducers

This method requires six linear accelerometers plusthree angular rate transducers. Three linearaccelerometers and the angular velocity sensors areplaced, on a single block, at the datum point C. Thethree linear accelerometers and the three angularvelocity transducers are oriented as the vehicleaxes x, y and z.


EN 1317-1:1998

BSI 1998

d 0 2e

0 21/2b 1/2b

[M] = 2b e 0 ; [M]21 = 0 1/2e 1/2e

b e 0 21/e 2d/2be d/2be

a12

ca

y2 b v ev

xv

y+ bv

yv

z( +v +x

2z2)

{p} = a

22

ca

z2 d(v +v ) + ev

xv

y+ bv

yv

zx2

y2

a32

ca

z2 d(v +v ) + ev

xv

y+ bv

yv

zx2

y2

Figure C.1 Ð Example B

This gives a direct measure of ca and v, so only threeunknowns remain to be determined, i.e. thecomponents of vÇ . These can be obtained by addingonly three linear accelerometers, as follows.

Let any of the latter three accelerometers be put atpoint iP in the direction of the unit vector in(i = 1, 2, 3); upon scalar multiplication by in, equation(C.2) takes the form:

im´vÇ = pi (C.11)where:

iR = iP 2 C is the position vector of iP;

im = iR ∧ in;

Pi = ai 2 cai 2 (víR)vi + (v´v)Ri;

ai = iaín is the measurement from the sensor atpoint iP;

cai = caín is the component of ca in the directionof in;

vi = vín is the component of v in the directionof in;

Ri = iRín is the component of iR in the directionof in.

Putting together equation (C.11) for the measurementsof the latter three transducers, the following final formis obtained:

(C.12)=[M] {vÇ } {p}

where:

1mx 1my 1mz

vx

px

[M] = 2mx 2my 2mz ; {vÇ } = vy ; p ={ } py (C.13)

3mx 3my 3mz vz pz

From equation (C.12) the angular acceleration is foundin the form:

(C.14)= 21{vÇ } [M] {p}Such a solution is possible only if matrix [M] isnon-singular, and this requires that the points iP andthe orientations in (i = 1, 2, 3) of the sensor becarefully selected.

With this all the nine kinematic parameters, i.e. {ca},{v} and {vÇ } are known. They can be used to computethe acceleration of any point P of the vehicle withequations (C.1), (C.2) or (C.3), or to reconstruct thevehicle path with a suitable procedure.

A good choice of the position and of the orientation ofthe transducers is reported in the following examples,where the point C is in the xz plane (symmetry plane),close to the vehicle centre of gravity, and the remaining


EN 1317-1:1998

BSI 1998

d 0 2e

0 1/2b 21/2b

[M] = b e 0 ; [M]21 = 0 1/2e 1/2e

2b e 0 21/e2d/2be 2d/2be

a12

ca

y+ b(v +v ) + ev

xv

y+ dv

yv

zx2

z2

{p} = a

22

ca

z2 d(v +v ) + ev

xv

y+ bv

yv

zx2

y2

a32

ca

z2 d(v +v ) + ev

xv

y+ bv

yv

zx2

y2

Figure C.2 Ð Example B

three accelerometers are mounted at two points,symmetrical with respect to the xz plane. Other goodchoices are also possible.


EN 1317-1:1998

BSI 1998

0 2d b

0 1/2b 1/2b

[M] = 2b e 0 ; [M]21 = 0 1/2e 1/2e

b e 0 1/b d/2be d/2be

a12

ca

x2 e(v +v ) + ev

xv

y+ dv

yv

zx2

z2

{p} = a

22

ca

z2 d(v +v ) + ev

xv

y+ bv

yv

zx2

y2

a32

ca

z2 d(v +v ) + ev

xv

y+ bv

yv

zx2

y2

Figure C.3 Ð Example C

C.5 Remarks

The first method proposed requires only linearacceleration transducers, but in a redundant number; itis straightforward for the evaluation of the accelerationof any point of the vehicle.

The second method, which requires a minimumnumber of transducers (six linear acceleration andthree angular velocity), is more suitable when pathreconstruction has to be made. Among the threelayouts shown in the examples, A is mostlyrecommended for collisions on the right side, B forcollisions on the left side and C for end on collisions.

In any case, the accuracy and the cost of the differenttransducers should also be considered in anycomparison of the two methods.


BSI389 Chiswick High RoadLondonW4 4AL

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