ISO 22135:2023

Road vehicles — Heavy commercial vehicles and buses — Calculation method for steady-state rollover threshold

This document describes a method for calculating steady-state rollover threshold of heavy commercial vehicles and buses, not considering the effects of active control systems. The calculation method considers the main factors that influence the rollover threshold, namely the height of centre of gravity, the track, the tyre lateral stiffness, and all factors that affect the vehicle roll stiffness. The considered compliances (e.g. tyre deformation) have a considerable influence on the effective track, and consequently on the steady-state rollover threshold. NOTE As an alternative to the described calculation method standard, the steady-state rollover threshold can be measured on a test track or with a tilt-table test as described in ISO 16333.

Véhicules routiers — Véhicules utilitaires lourds et bus — Méthode de calcul du seuil de renversement en régime permanent

General Information

• Status: Published
• Publication Date: 09-Jan-2023
• ICS: 43.080.01 - Commercial vehicles in general
• Technical Committee: ISO/TC 22/SC 33 - Vehicle dynamics and chassis components
• Drafting Committee: ISO/TC 22/SC 33/WG 6 - Vehicle dynamics of heavy commercial vehicles and buses
• Current Stage: 6060 - International Standard published
• Start Date: 10-Jan-2023
• Due Date: 03-Jan-2023
• Completion Date: 10-Jan-2023

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 22135
First edition
2023-01
Road vehicles — Heavy commercial
vehicles and buses — Calculation
method for steady-state rollover
threshold
Véhicules routiers — Véhicules utilitaires lourds et bus — Méthode de
calcul du seuil de renversement en régime permanent
Reference number
ISO 22135:2023(E)
© ISO 2023

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ISO 22135:2023(E)
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© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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ISO 22135:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Properties . 4
4.1 Vehicle properties used for calculation . 4
4.2 Required parameter accuracy . 5
5 Principle . 5
6 Calculation method . 6
6.1 General . 6
6.2 Calculation of vehicle effective track . 6
6.3 Calculation of vehicle roll stiffness. 7
6.4 Calculation of vehicle effective tyre lateral stiffness . 7
6.5 Calculation of steady-state rollover threshold . 7
Annex A (informative) Sample results . 9
Bibliography .10
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ISO 22135:2023(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
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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
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 33,
Vehicle dynamics and chassis components.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO 22135:2023(E)
Introduction
The dynamic behaviour of a road vehicle is a most important aspect of active vehicle safety. Any given
vehicle, together with its driver and the prevailing environment constitutes a closed-loop system which
is unique. The task of evaluating the dynamic behaviour is therefore very difficult, since the significant
interaction of these driver-vehicle road elements are each complex in themselves. A complete and
accurate description of the behaviour of the road vehicle inevitably involves information obtained from
a number of different tests.
Moreover, insufficient knowledge is available to correlate overall vehicle dynamic properties with
accident prevention. A substantial amount of work is necessary to acquire sufficient and reliable data
on the correlation between accident prevention and vehicle dynamic properties in general.
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INTERNATIONAL STANDARD ISO 22135:2023(E)
Road vehicles — Heavy commercial vehicles and buses —
Calculation method for steady-state rollover threshold
1 Scope
This document describes a method for calculating steady-state rollover threshold of heavy commercial
vehicles and buses, not considering the effects of active control systems. The calculation method
considers the main factors that influence the rollover threshold, namely the height of centre of
gravity, the track, the tyre lateral stiffness, and all factors that affect the vehicle roll stiffness. The
considered compliances (e.g. tyre deformation) have a considerable influence on the effective track, and
consequently on the steady-state rollover threshold.
NOTE As an alternative to the described calculation method standard, the steady-state rollover threshold
can be measured on a test track or with a tilt-table test as described in ISO 16333.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 8855, Road vehicles — Vehicle dynamics and road-holding ability — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in in ISO 8855 and the following
shall apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
steady-state rollover threshold
a
srt
maximum lateral acceleration that the vehicle can sustain in a steady state turn without rolling over
3.2
first lift-off lateral acceleration
a
yf
lateral acceleration, at which the first wheel lift-off occurs
3.3
total lift-off lateral acceleration
a
yt
lateral acceleration, at which theoretically all axles lift from the ground
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ISO 22135:2023(E)
3.4
track
b
distance between the contact centres on a single wheel axle, measured parallel to the Y axis, with the
vehicle at rest on a horizontal surface
Note 1 to entry: For dual wheel axles, it is the distance between the points centrally located between the contact
centres of the inner and outer dual wheels.
3.5
equivalent track
b
e
track (3.4) for a dual wheel axle
Note 1 to entry: For single wheel axles, equivalent track is equal to the track.
3.6
kingpin representative track
b
k
representative track (3.4) for the kingpin of a semitrailer, used for calculation of vehicle effective track
(3.7)
3.7
vehicle
...