Bsi bs au 210 1 1987 (2000)

BRITISH STANDARD AUTOMOBILE SERIES BS AU 210 1 1987 Drawbars for caravans and light trailers — Part 1 Method for calculation of the mechanical strength of steel drawbars UDC [629 11 – 43 + 728 76] 629[.]

Drawbars for caravans

U C [ 62 1 – 4 +7 8.7 ]6 9.1 0 3.1

This Bri shStan ard, ha ing

b en pre ared u der the

directonof the Automo ile

Stan ards Commi e ,was

published u der the authoriy

ofthe Bo rd of BSI an comes

into fect on

3 J n ary1 8

© BSI0 -2 0

The folowing BSI references

relate to the work on this

stan ard:

Commi e reference AUE/8

Draft for comment 8 / 78 4 DC

ISBN 0 5 0 1 6 0 5

The prep ration of this BritishStand rd was entrusted b the Automobi e

Stand rds Commit e ( AUE/-) to Tech ical Commit e AUE/8, upon which the

fol owing bodies were represented:

Association of Traier Man facturer

British Compres ed Air Society

Carav an Club

Chief and Assistant Chief Fire Oficer ’ Association

Consumer Stand ards Adv isory Commit e of BSI

Dep rtment of Tra e and Industry ( Vehicle Div ision)

Dep rtment of Transport ( Hig hway s)

National Carav an Cou ci Limited

Society of Motor Man facturer and Tra er Limited

Am endm ents is ued sinc publ cation

Amd No Date of is ue Comments

Pag e

This Part of BS AU2 0 has be n prep red u d er the d irection of the Automobie

Stand ards Commit e an is b sed on ISO7 41-1:19 3 “ R oa d vehicle —

Ca r a va ns a nd lght tr a iler s— Ca lcula tion o the me ha nica l str ength o the

d r a wba r— Pa r t1: Ste l d r a wba r s”, publ shed b the International Org anization

for Stand rdization ( ISO)

It d ifer f om the International Stand ard in two respects Fir tly , the ISO

d ocument refer to ISO/TR41 4 in relation to the l mits on the v ertical static

load s on the coupl ng head , whereas in this stand rd reference to ISO/TR41 4

has be n d eleted an v alues of24 N to7 5N hav e be n substituted

Secondly , ISO7 41-1 refer to ISO7 41-2: this reference has be n chang ed to

BSA U2 0-2 For ease of reproduction, the ISO text has be n used Some

terminolog y an certain conv entions are not identical with those used in

BritishStand rds; at ention is d rawn especialy to the folowing

The comma has be n used as a decimal marker In BritishStand ards it is cur ent

practice to use a ful point on the b selne as the decimal marker

The Tech ical Commit e has rev iewed the prov isions of ISO1 7 and ISO723 ,

to which reference is ma e in the text, and has decid ed that they are ac epta le

for use in conju ction with this stand ard

A British Stand ard d oes not purport to includ e al the neces ary prov isions of a

contract User of British Stand rd s are responsible for their cor ect a plcation

Com pl anc with a British Standard does not ofitself confer im m unity

f om leg al o l g ations

Sum mary of pag es

This document comprises a f ont cov er, an insid e font cov er, p g esi andi ,

p g es1 to4, an inside b ck cov er and a b ck cov er

This stand rd has be n up ated ( se copy rig ht d ate) an ma hav e ha

amendments incorporated This wi l be indicated in the amendment ta le on the

inside f ont cov er

1 Scope

This Part of BS AU2 0 g iv es a simplfied proced ure for the calculation of the mechanical streng th of

drawb r for carav ans an lg ht trai er

1)

where the v ertical static for e on the couplng head is not les

than24 N or g reater than7 5N

2 Field ofa ppl cation

Calculations shown in this Part of BS AU2 0 a ply only to ste l drawb r , of welded an other than

weld ed construction

For weld ed d rawb r , only those ty pes of ste l which contain not more than0,2 % carbon and the

weld abi ity of which is g uarante d b the man facturer shal be used

The weld ing proced ure requirements g iv en b the man facturer shal be met ( preheating , for ex mple)

NOT Drawb r made fom other materials wil b de lt wih in BS AU2 0-2

2)

3 Ref r nces

The titles of the publcations refer ed to in this Part of BS AU2 0 are l sted on the insid e b ck cov er

4 Symbols and definitions

1)

Categ ories0 an 0 as in E E/UNO clas ificaton

2)

At stag e of draft

Fig ure 1 — Drawbar sketch

l is the d istance, in metres, fom the v ertical a is of the coupl ng dev ice to the fir t fixing point on the

traier fame;

l is the distance, in metres, fom the v ertical a is of the couplng d ev ice to the drawb r section

cor esponding to the ma imum strain rate;

e is the distance, in metres, fom the horiz ntal a is of the couplng dev ice to the drawb r neutral fibre

at the fir t fixing point on the trai er f ame;

e

x

is the distance, in metres, fom the horiz ntal a is of the couplng dev ice to the drawb r neutral fibre

at the c os section cor esponding to the ma imum strain rate;

P is the ma imum manufacturer’s total mas , in ki og rammes ( se ISO723 );

D is the v alue, in newtons, determined b calculation for the long itudinal for es oc ur ing betwe n

tractor v ehicle and trai er:

k is the co ficient for a d rawb r long er than2,5m to be d etermined as fol ows:

k=1,25–0,1 l with k

in

=0,6

2 0 0×P

2 0 0+P

×

=

5 Resista nce ca lcula tion

The calculation shal be car ied out ov er the whole leng th l of the d rawb r taking into ac ou t distances l

an e

x

in ord er to d etermine ma imum strain rate The strain rate shal be checked at the position where

the ma imum bend ing moment oc ur when l=l and e=e

x

5.1Calculation of the m axim um bending mom ent, ex res ed in newton m etres, for the drawbar

with e/l<0,15 and e

x /l

x

<0,15

Only flexure is taken into ac ou t for the calculation

5.1.1 Drawb r of length2,5m or les :

— for braked trai er :

M

f

=0,3 P g l

— for u braked trai er :

M

f

=0,24P g l

5.1.2 Drawbar of leng th g reater than2,5m:

— for braked trai er :

M

f

=0,3 P g k l

— for u braked trai er :

M

f

=0,24 P g k l

5.2 Calculation of the m aximum bending m om ent, ex res ed in newton m etres, for drawbar

with e/l>0,15 and e

x /l

x

>0,15

Only flexure is taken into ac ou t for the calculation

Thre bend ing moments, M

f , M

fD and M

fR shal be calculated; the larg est v alue of the thre shal be used

for the calculation of the ma imum ad mis ible stres (M

fma )

5.2.1 Drawb r of leng th2,5m or les :

— for braked trai er :

M

f

=0,3 P g l

M

fD

=0,8 D e

x

M

fR

=0,7 ( M

f +M

fD )

— for u braked traier s:

M

f

=0,24 P g l

M

fD

=1,0 D e

x

M

fR

=0,7 ( M

f +M

fD )

5.2.2 Drawb r of leng th g reater than2,5m :

— for braked trai er :

M

f

=0,3 P g k l

M

fD

=0,8 D e

x

M

fR

=0,7 ( M

f +M

fD )

— for u braked traier s:

M

f

=0,24 P g k l

M

fD

=1,0 D e

x

M

fR

=0,7 ( M

f +M

fD )

5.3 Perm is ible stres

Stres rates Ö calculated for the whole leng th of the drawb r shal not exce d the alowed stres Ö

c :

5.3.1 Drawbar fa ricated b m eans other than welding :

0,6 Ö

B min

W Ö

c

u0,8 Ö

s

where

Ö

c

is the permis ible stres , in newtons per sq uare mi lmetre;

Ö

B

is the ultimate tensi e stres , in newtons per square mi imetre;

Ö

s

is the y ield stres , in newtons per sq uare mi imetre

5.3.2 Welded drawbar :

0,4 Ö

B min

W Ö

c

u 0,6 Ö

s

where

is the section modulus of drawb r

c os -section cor espond ing to the ma imum

bending moment

Fig ure 2 — Perm is ible stres

Ö M

f

I

V

-=

I

V

b

Publica tions referred to

BS AU2 0, D r a wba r s, ca r a va ns a nd lght tr a iler s

BS AU2 0-2, Method f r ca lcula tion o the me ha nica l str ength o d r a wba r s ma d e fr om ma ter ia ls other

tha n ste l

3)

ISO1 7 , Roa d vehicle — Weights— Voca bula r y

ISO/TR41 4, R oa d vehicle — Ca r a va ns a nd lght tr a iler s— Sta tic loa d on ba ll couplngs

)

ISO723 , R oa d vehicle — Ma ss s a nd d imensions o ca r a va ns— Ter ms a nd d efiniions

3)

At stag e of draft

4)

Refered to in the foreword only

3 9 Chiswick Hig h Roa

London

W 4 4AL

BSI is the independent national bod y responsible for prep ring

BritishStand ard s It presents the UK v iew on stand ard s in Europe an at the

international lev el It is incorporated b Roy al Charter

Revisions

BritishStand ards are up ated b amendment or rev ision User of

BritishStand ard s should make sure that they pos es the latest amendments or

editions

It is the constant aim of BSI to improv e the qual ty of our products and serv ices

W e would be g rateful if any one find ing an inac uracy or ambig uity whi e using

this BritishStand rd would inform the Sec etary of the technical commit e

responsible, the identity of which can be fou d on the inside f ont cov er

Tel:0208 9 9 0 Fa :0208 9 7 0

BSI ofer member an indiv id ual up ating serv ice caled PLUS which ensures

that subs riber automaticaly receiv e the latest editions of stand rds

Buying standards

Order for al BSI, international an foreig n stand ard s publcations should be

a d res ed to Customer Serv ices Tel:0208 9 9 01 Fa :0208 9 7 01

In response to ord er for international stand rd s, it is BSI pol cy to sup ly the

BSI implementation of those that hav e be n publ shed as BritishStand rds,

unles otherwise requested

Inform ation on standards

BSI prov id es a wide rang e of information on national, European and

international stand rds throug h its Library and its Tech ical Help to Ex orter

Serv ice Various BSI electronic information serv ices are also av aia le which g iv e

d etais on al its prod ucts an serv ices Contact the Information Centre

Tel:0208 9 71 1 Fa :0208 9 7 4

Subs ribing member of BSI are kept up to d te with stand rd s dev elopments

and receiv e substantial d is ou ts on the pur hase price of stand rds For d etai s

of these and other benefits contact Member hip Ad ministration

Tel:0208 9 7 02 Fa :0208 9 7 01

Co yrig ht

Copy rig ht subsists in al BSI publcations BSI also holds the copy rig ht, in the

UK, of the publcations of the international stand ardization bod ies Except as

permit ed u der the Cop rig ht, Desig ns and Patents Act 19 8 no extract ma be

reproduced , stored in a retriev al sy stem or transmit ed in any form or b any

means – electronic, photocopy ing , recording or otherwise – without prior writ en

permis ion fom BSI

This do s not preclude the fe use, in the cour e of implementing the stand ard,

of neces ary detai s such as sy mbols, and siz , ty pe or g ra e d esig nations I these

d etais are to be used for any other purpose than implementation then the prior

writ en permis ion of BSI must be obtained

I permis ion is g ranted, the terms ma includ e roy alty p y ments or a lcensing

ag re ment Detais and a v ice can be obtained f om the Copy rig ht Manag er

Tel:0208 9 7 7