Mobile cranes — Experimental determination of crane performance — Part 2: Structural competence under static loading

ISO 11662-2:2014 presents a test method for the structural competence under static loading of mobile cranes. This test method is to provide a systematic, non-destructive procedure for determining the stresses induced in crane structures under specified conditions of static loading through the use of resistance-type electric strain gauges, and to specify appropriate acceptance criteria for specified loading conditions. ISO 11662-2:2014 applies to mobile construction-type lifting cranes utilizing a) rope-supported, lattice boom attachment or lattice boom, and fly jib attachment, b) rope-supported, mast attachment and mast-mounted boom, and fly jib attachment, or c) telescoping boom attachment or telescopic boom and fly jib attachment. Mobile crane manufacturers can use ISO 11662-2:2014 to verify their design for the mobile crane types illustrated in its Annex E.

Grues mobiles — Détermination expérimentale des performances des grues — Partie 2: Compétence structurale sous le chargement statique

General Information

Status
Published
Publication Date
29-Oct-2014
Current Stage
9093 - International Standard confirmed
Start Date
01-Jun-2020
Completion Date
01-Jun-2020
Ref Project

Buy Standard

Standard
ISO 11662-2:2014 - Mobile cranes -- Experimental determination of crane performance
English language
40 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 11662-2
First edition
2014-11-01
Mobile cranes — Experimental
determination of crane
performance —
Part 2:
Structural competence under static
loading
Grues mobiles — Détermination expérimentale des performances des
grues —
Partie 2: Compétence structurale sous le chargement statique
Reference number
ISO 11662-2:2014(E)
ISO 2014
---------------------- Page: 1 ----------------------
ISO 11662-2:2014(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2014

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2014 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 11662-2:2014(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Symbols and abbreviated terms ........................................................................................................................................................... 3

5 Limitations .................................................................................................................................................................................................................. 5

6 Method of loading ................................................................................................................................................................................................ 5

6.1 Suspended load....................................................................................................................................................................................... 5

6.2 Side load (SL)............................................................................................................................................................................................ 5

6.3 Deflection criteria ................................................................................................................................................................................. 6

7 Facilities, apparatus, and material .................................................................................................................................................... 9

8 Preparation for test ........................................................................................................................................................................................... 9

9 Test procedure and records ...................................................................................................................................................................10

9.1 Final test preparation .....................................................................................................................................................................10

9.2 Zero stress condition ......................................................................................................................................................................10

9.3 Dead load stress condition ........................................................................................................................................................10

9.4 Working load stress .........................................................................................................................................................................10

9.5 Overload test condition ................................................................................................................................................................11

10 Stress evaluation ...............................................................................................................................................................................................11

10.1 Class I — Uniform stress areas ..............................................................................................................................................12

10.2 Class II — Stress concentration areas ..............................................................................................................................12

10.3 Class III — Column buckling stress areas .....................................................................................................................12

10.4 Class IV — Local plate buckling areas ..............................................................................................................................13

Annex A (normative) Strength of materials ...............................................................................................................................................14

Annex B (normative) Column buckling stress .........................................................................................................................................17

Annex C (normative) Test conditions and strength margins ....................................................................................................24

Annex D (informative) Report format ..............................................................................................................................................................33

Annex E (informative) Typical crane examples ......................................................................................................................................35

Bibliography .............................................................................................................................................................................................................................40

© ISO 2014 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 11662-2:2014(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the meaning of ISO specific terms and expressions related to conformity

assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers

to Trade (TBT) see the following URL: Foreword - Supplementary information

The committee responsible for this document is ISO/TC 96, Cranes, Subcommittee SC 6, Mobile Cranes.

ISO 11662 consists of the following parts, under the general title Mobile cranes — Experimental

determination of crane performance:
— Part 1: Tipping loads and radii
— Part 2: Structural competence under static loading
iv © ISO 2014 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 11662-2:2014(E)
Introduction

When design calculations are made for mobile cranes, they are based on an ideal model in which all

members and components are perfectly straight and fabrication has been exact. For tension members

and members subjected to bending, the difference between the real crane and the ideal model is usually

not significant. But, for compression members subject to column buckling, an allowance for deviation in

straightness and fabrication is necessary.

When mobile cranes are tested non-destructively by means of strain gauges, the stresses determined

intrinsically include these effects of deviations in straightness and accuracy of fabrication.

This test method is intended to describe the approximate maximum loading conditions to which any

component of the entire load-supporting structure of a crane is subjected (See Annex D). In some

cases, a more severe loading condition(s) can be indicated by analysis. In these cases, the more severe

condition(s) can be added to or substituted for the specified test loading condition(s). This test method

also classifies stress areas as Types I (Uniform Stress Areas), II (Stress Concentration Areas), III (Column

Buckling Areas), and IV (Local Plate Buckling Areas; see Clause 10), and defines limits for each class.

Results can be used to correlate boom system calculation results for Class III stress areas as given by

boom system calculations. Test results for Class I stress areas throughout the structure can be used to

check any available calculations. This test method evaluates Class II stress areas for which calculations

are seldom available. Class IV stress areas, where disproportionately high stress readings can occur, can

be reviewed for better insight by calculation methods.

A production boom system that has been rated by the methods of this part of ISO 11662 can be used

on another machine without re-testing by the methods specified herein, provided the same analytical

procedure shows its stress levels will be less than or equal to the stress levels in the original application,

and provided that the supporting structure is as rigid as the original mounting. Rigidity of the supporting

structure is determined by the change in the slope of the jib foot axis as test loads are applied.

© ISO 2014 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 11662-2:2014(E)
Mobile cranes — Experimental determination of crane
performance —
Part 2:
Structural competence under static loading
1 Scope

This part of ISO 11662 applies to mobile construction-type lifting cranes utilizing

a) rope supported, lattice boom attachment or lattice boom, and fly jib attachment (see Annex E,

Figure E.3),

b) rope supported, mast attachment and mast mounted boom, and fly jib attachment (see Annex E,

Figures E.1 and E.2), or

c) telescoping boom attachment or telescopic boom and fly jib attachment (see Figure E.4).

Mobile crane manufacturers can use this part of ISO 11662 to verify their design for the mobile crane

types illustrated in Figures E.1 through E.4.

This test method is to provide a systematic, non-destructive procedure for determining the stresses

induced in crane structures under specified conditions of static loading through the use of resistance-

type electric strain gauges, and to specify appropriate acceptance criteria for specified loading

conditions.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

ISO 9373:1989, Cranes and related equipment — Accuracy requirements for measuring parameters during

testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
strain

relative elongation or compression of material at any given point with respect to a specific plane passing

through that point, expressed as change in length per unit length (m/m)
3.2
stress

internal force per unit area resulting from strain, expressed in pascals (Pa) or newtons/square meter

Note 1 to entry: For this document, megapascals (Mpa) will be used for brevity.
© ISO 2014 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 11662-2:2014(E)
3.3
yield point

stress at which a disproportionate increase in strain occurs without a corresponding increase in stress

Note 1 to entry: For purposes of this code, yield point is to be considered as the minimum 0,2 % offset tensile yield

point or yield strength specified by the appropriate standard for the material used.

3.4
critical buckling stress

average stress which produces an incipient buckling condition in column-type members (See Annex C)

3.5
initial reference test condition

defined no-stress or zero-stress condition of the crane structure after the “break-in” as established by

a) supporting the structure on blocking to minimize the effects of gravity, or

b) the crane structure components in an unassembled state or any alternate method that will establish

the zero-stress condition. Under this condition, the initial reference reading for each gauge is

obtained, N
3.6
dead load stress condition

completely assembled crane structure on the test site and in the position or attitude, ready to apply the

specified live load at the specified radius

Note 1 to entry: Under this condition, the second reading for each gauge is obtained, N .

Note 2 to entry: The hook, hook block, slings, etc. are considered part of the suspended load but may be supported

by the crane when this reading is taken. For dead load purposes, the hook in the “home” position – suspended

from the crane without lifting the test load. This position has to be repeated after placing the load back on the

ground (see 9.4.4).
3.7
dead load stress

stress computed as defined in Clause 10 by using the difference in the readings obtained in 3.6 and 3.5

for each gauge (N – N )
2 1
3.8
working load stress condition

completely assembled crane structure on the test site and in the specified position, supporting the

specified rated load

Note 1 to entry: Under this condition, the third reading for each gauge is obtained, N .

3.9
working load stress

stress computed as defined in Clause 10 by using the difference in the readings obtained in 3.8 and 3.5

for each gauge (N – N )
3 1
3.10
resultant stress

stress induced in the structure as a result of dead load stress (S ) or the working load stress (S ),

1 2
whichever is greater in absolute magnitude
2 © ISO 2014 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 11662-2:2014(E)
3.11
column average stress

direct compression stress in a column or the average stress computed from several gauges located at the

section (see Annex B)
3.12
column maximum stress

maximum compression stress in a column computed from the plane of buckling as established from

several gauges located at the section (see Annex B)
3.13
loadings

application of weights and/or forces of the magnitude specified under the condition specified

3.14
load radius

horizontal distance between the axis of rotation of the turntable of the crane and the vertical axis of the

hoist line or load block when the crane is erected on a level site
4 Symbols and abbreviated terms
E modulus of elasticity
K effective length factor for a column
L un-braced length of column
L length of boom
L length of fly jib
L small arbitrary projected length of fly jib along x-axis
L projected length of fly jib strut along y-axis
n strength margin

n strength margin, Class I area, ratio of yield strength to resultant or equivalent stress

n strength margin, Class II area, ratio of yield strength to resultant or equivalent stress

n strength margin, Class III area, derived from an interaction relationship
N strain reading at initial reference test condition
N strain reading at dead load stress condition
N strain reading at working load stress condition
r radius of gyration
RL rated load as specified by manufacturer
“R” plane (Figure 1) perpendicular to boom foot pin centreline (CL)
RR rated radius as specified by manufacturer
S stress
© ISO 2014 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO 11662-2:2014(E)
S dead load stress
S working load stress
S column average stress computed from several gauges at a cross section
S critical buckling stress for axially loaded columns
SL side load, i.e. 0,02 × RL;

percentage of side load expressed as a percentage of rated load or %RL = Percentage of

%SL
rated load
SLL side load left
SLR side load right
S maximum compression stress in a column
S stress at the proportional limit
S resultant stress
S maximum residual stress in compression
S stress at the yield point
S’ equivalent uniaxial stress

t horiz. distance from the load centre to the front pad reaction centre for each box jib section

σ tensile yield stress
σ maximum principal stress
σ minimum principle stress
Z’ lattice boom tip slope (out of plane)
Z lattice boom tip deflection from plane “R”
Z fly jib tip deflection from plane “R”
Z boom deflection at a point l back from the boom tip
1 1
Z fly jib strut deflection at its tip
α imperfection factor
β fly jib offset angle from centreline (CL) jib
ε strain
ε strain recorded from leg “a” of rosette
ε strain recorded from leg “b” of rosette
ε strain recorded from leg “c” of rosette
ε strain recorded from leg “d” of rosette
ε maximum principal strain
4 © ISO 2014 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 11662-2:2014(E)
ε minimum principal strain
µ units of strain, 10
θ fly jib tip rotation about x-axis (radians)
π Pi = 3,1416
τ shear yield stress
ν Poisson’s ratio
X relative buckling stress ( = S /S )
cr y
initial relative slenderness
relative slenderness (= λ/λ )
slenderness ratio (= KL/r)
 
λ reference slenderness ratio =π
 
 
S allowable buckling stress
S Euler’s buckling stress
S Jager’s buckling stress
5 Limitations

5.1 This method applies to load-supporting structures as differentiated from power transmitting

mechanisms. It is restricted to measuring stresses under static conditions and a general observation after

overload conditions.

5.2 Personnel competent in the analysis of structures and the use of strain-measuring instruments are

required to perform the tests.
6 Method of loading
6.1 Suspended load

The specified load suspended at the specified radius and held stationary a short distance above the

ground. The weight of the hook, block, slings, etc., shall be included as part of the specified suspended

load.
6.2 Side load (SL)

When the test specification requires side loading, the force displacing the suspended load should

be horizontal and perpendicular to the plane containing the axis of upper structure rotation and

the centreline of the undeflected boom. The side load shall be applied in each direction. Side loading

is applied to simulate the various effects associated with machine operation including a 9 m/s wind

loading that might be encountered.
© ISO 2014 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO 11662-2:2014(E)
6.2.1 Lattice boom attachment

For lattice boom attachments, the side load that is to be applied for the conditions listed in Table C2 is as

follows. The side load shall be applied as 2 % (0,02 RL) of the rated load in each direction.

6.2.2 Mast attachments

For mast attachments, the side load percentage that is to be applied in each direction at the load

attachment point for the conditions listed in Table C1 is to be a minimum of 2 % (0,02 RL) of the rated

load in each direction.
6.2.3 Telescoping boom attachment

For telescoping boom attachments, the side load that is to be applied for the conditions listed in Table C3

is as follows. The side load shall be applied as 3 % (0,03 RL) of the rated load in each direction with the

boom over the end of the machine.
6.3 Deflection criteria

The usability of a latticed column [i.e. lattice boom and fly jib(s) combination] or a telescoping boom

attachment is sometimes affected by the elastic stability of the overall column as well as of the individual

members. Incipient out of plane elastic instability is indicated by excessive boom and/or fly jib tip

deflection (sideways) as the attachment is side loaded when suspending a rated load. The following

lateral deflection limits are therefore imposed.
6.3.1 Lattice boom attachments

The lateral deflection criteria for the rated load and side load of Table C2 are as follows. First, the

deflection of the total boom and jib combination shall be less than or equal to 2 % of the total combination

length. Furthermore, the deflection of each individual boom or fly jib member shall be less than or equal

to 2 % of the length of that member. To satisfy these criteria, it should be noted that the deflection of

an individual member does not include the deflection, rotation, or slope of the member to which it is

mounted.

For a single fly jib mounted on a boom, the following relationship is given (Figure 1):

ZL≤′00,c2 ++ZZ LLosβθ+ sinβ (1)
() ()
jj bj j
The following values are measured.
Z fly jib tip deflection
Z lattice boom tip deflection
Z lattice boom deflection at a distance L down from the boom tip
1 1
Z fly jib strut deflection at the tip
The following values are calculated.
6 © ISO 2014 – All rights reserved
---------------------- Page: 11 ----------------------
ISO 11662-2:2014(E)
Slope:
ZZ′=()−ZL/ (2)
b 11
Rotation:
θ= ZZ− L (3)
b 22

If slope (Z′) and rotation (θ) are not measured, the last two terms of Formula (1) may be deleted.

© ISO 2014 – All rights reserved 7
---------------------- Page: 12 ----------------------
ISO 11662-2:2014(E)
Figure 1 — Deflection measurement related terms —
Lattice boom with fly jib
6.3.2 Telescoping boom attachments

For telescoping boom attachment crane structures, no tip deflection limitations have been established.

Deflection of the mast attachment, the mast mounted boom, and fly jib shall be measured and recorded

when the system is stable.
8 © ISO 2014 – All rights reserved
---------------------- Page: 13 ----------------------
ISO 11662-2:2014(E)
6.3.3 Mast attachments

For mast attachment crane structures, no tip deflection limitations have been established. The deflection

of the telescopic boom attachment and fly jib shall be measured and recorded when the system is stable.

7 Facilities, apparatus, and material

7.1 A concrete or other firm supporting surface, sufficiently large to provide for unobstructed

accomplishment of the tests required. Where tests are to be performed on crawler tracks, the machine

shall be level within 0,25 % grade.

7.2 Means to measure levelness of the axis of the jib foot; accuracy 0,1 % of grade (see ISO 9373).

7.3 Means for determining the load radius to an accuracy of ±1 %, not to exceed 150 mm.

7.4 Means for producing traverse displacement of the suspended load and means for measuring the

magnitude of the displacing force; accuracy ±3 % of measured force.

7.5 Temperature compensated strain gauges, cement, waterproofing compounds, and other necessary

gauge installation equipment.

7.6 Strain recording system. It is the intent that commercially available, high quality, reliable instruments

be used in the performance of this test. Accuracy of the recording system shall be determined to be ±2 %

of the reading over the range of 500 μ m/m to 3 000 μ m/m strain (determined in suitable increments).

Calibration can be accomplished by electrical shunts or by pre-calibrated strain bar.

7.7 Test weights and lifting apparatus of known weights accurate to within ±1 %.
7.8 Means for measuring side deflection of the boom and fly jib within 50 mm.
8 Preparation for test

8.1 An analysis of each structure sufficient to locate highly stressed areas shall be made. The strain

gauge location and direction shall be determined from this analysis as well as from the use of other

experimental techniques where necessary.

8.2 Perform a detailed inspection of the crane to ensure that all mechanical adjustments and condition

of load supporting components conform to manufacturers’ published recommendations. Check that the

crane is equipped in compliance with the test specifications.

8.3 A previously un-worked crane should be given a “break-in” run at or near each anticipated test

loading to mechanically relieve residual stresses that might have developed during manufacture and to

minimize the possibility of “gauge zero shift” during the test.

8.4 Perform a thorough inspection after the “break-in” to reveal areas of high stress as evidenced by

paint checking, scale flaking, or other indications of deformation.

8.5 Bond strain gauges at the points determined by prior analysis (see 8.1) and any areas selected as a

result of the inspection conducted in 8.4. Only competent personnel using proven materials and practices

can be employed to ensure that all gauges are of the correct type, properly oriented, and securely bonded

to measure strains correctly.
© ISO 2014 – All rights reserved 9
---------------------- Page: 14 ----------------------
ISO 11662-2:2014(E)

8.6 Determine the minimum yield strength and the modulus of elasticity for the material at each

gauge location by referring to the material certifications, if available, applicable standards, or Annex B.

Determine the critical buckling stress when applicable (see Annex B).
9 Test procedure and records
9.1 Final test preparation

9.1.1 Locate the machine on the test course and lock travel brakes and latches. Level the machine to

within 0,25 % grade in the unloaded condition by shimming or by jacking. Do not re-level after the load

has been applied to the machine.

NOTE If the test is for operation on outriggers, jack the crane to a position where all the tires or tracks are

unloaded, unless the manufacturer’s rating chart requires some other conditions.

9.1.2 Connect strain measuring system and calibrate gauges and instruments. Correct any malfunctions.

9.2 Zero stress condition

If the assembled crane is to be used as the initial reference test condition, obtain these readings. If the

unassembled components are to be used as the initial reference test condition, obtain these readings.

Reassemble the crane and make all mechanical adjustments.
9.3 Dead load stress condition

9.3.1 Set the revolving upper structure to the specified position relative to the lower structure. Lock the

swing brake or latch.

9.3.2 Set the attachment angles and lengths to develop the specified load radius.

9.3.3 Read all strain gauges for dead load stress condition (see 3.6). Compute the dead load stress (S ) at

each gauge (see 3.7) and record on the test data sheet (see Annex D).

NOTE A new dead load stress condition is established each time the position, attitude, or configuration

is changed to suit the specified tests and operations: therefore, 9.3.1 to 9.3.3 shall be repeated for each new

condition.
9.4 Working load stress

9.4.1 Prepare a test load which together with the hook, block, slings, etc., weighs within ±1 % of the

specified load.

9.4.2 Suspend the test load (see 6.1) and apply side load (see 6.2) as required by specifications.

9.4.3 Read required strain gauges for working load stress condition. Compute the working load stresses

(S ) for each required gauge and record the test data. Measure and record tip side deflection due to

suspended load and side load.

9.4.4 Release side load and lower suspended load, returning crane to dead load condition. Read required

strain gauges and compare with reading taken under 9.3. If the deviation for any gauge exceeds ±0,03 S /E,

determine cause, correct, and repeat all procedures until consistent readings are obtained.

10 © ISO 2014 – All rights reserved
---------------------- Page: 15 ----------------------
ISO 11662-2:2014(E)

NOTE Since temperature changes and the loading from even a moderate wind on long booms and fly jibs

affects strain gauge readings, testing should be done under as
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.