Table Of ContentSTRUCTURAL CRASHWORTHINESS
AND FAILURE
STRUCTURAL
CRASHWORTHINESS
AND FAILURE
Edited by
NORMAN JONES
Department of Mechanical Engineering
The University of Liverpool
Liverpool, UK
and
TOMASZ WIERZBICKI
Department of Ocean Engineering
Massachusetts Institute of Technology
Cambridge, Massachusetts, USA
Taylor & Francis
Taylor & Francis Group
LONDON AND NEW YORK
By Taylor & Francis,
2 Park Square, Milton Park, Abingdon, Oxon, 0X14 4RN
Transferred to Digital Printing 2005
British Library Cataloguing in Publication Data
Structural Crashworthiness and Failure
I. Jones, Norman II. Wierzbicki, Tomasz
624.1
ISBN 1-85166-969-8
Library of Congress CIP Data
Structural crashworthiness and failure/edited by Norman Jones and
Tomasz Wierzbicki.
p. cm.
Includes bibliographical references and index.
ISBN 1-85166-969-8
1. Impact. 2. Structural failures. 3. Metals—Impact testing.
I. Jones, Norman. II. Wierzbicki, Tomasz.
TA654.2.S77 1993
624.1 '71—dc20 92-37840
CIP
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To Jenny and to Margaret
PREFACE
This book contains 12 chapters that were presented as invited lectures
at the Third International Symposium on Structural Crashworthiness
held at the University of Liverpool, Liverpool, UK, 14-16 April 1993.
This Symposium was a logical continuation and extension of two
previous Symposia held in 1983 and 1988, and was organised in order to
examine recent developments in structural crashworthiness and failure.
Particular emphasis has been given in this book to the failure
predictions for ductile metal structures under large dynamic loads and
to the behaviour of composite and cellular structures.
The First International Symposium of Structural Crashworthiness was
organised by the present editors in 1983, at the University of Liverpool.
The proceedings were published in the book Structural Crash
worthiness1 and in the special issues of two international journals.2,3 It
was the principal objective of the first meeting to summarize the
advances in the structural crashworthiness of a wide range of transpor
tation modes (aircraft, automobiles, buses, helicopters, ships, trains
and offshore platforms) and to review the developments in the
non-linear large-deflection response of structural members and energy
absorbing systems. This meeting emphasized the ductile behaviour of
structures and components.
The Second International Symposium on Structural Crashworthiness
was organised five years later at MIT, with the proceedings published in
the book Structural Failure4 and in special issues of two international
journals.5,6 This meeting emphasized various aspects of structural
failure that limit integrity and energy absorbing capacity in many
practical situations.
The topics discussed in the first and second symposia are fundamental
vii
viii Preface
to the areas of structural crashworthiness and energy absorbing systems
as well as for safety calculations and hazard assessments in many
industries. For example, a study of the dynamic inelastic behaviour of a
side plating on a ship involved in a collision is also of interest for the
hazard assessment of an offshore platform deck struck by a dropped
object. Similarly, the dynamic transverse indentation of a cylindrical
shell or tube is relevant to the structural crashworthiness of an offshore
platform brace or leg struck by a ship or the hazard assessment of a
land-based gas pipeline struck by a dropped object during maintenance
operations, for example. Many other examples can be found from a
wide spectrum of industries. These are highly non-linear dynamic
structural problems with complex geometries, for which it is essential to
integrate the material behaviour into the structural response.
The chapters in this book are now introduced briefly.
Chapters 1-4 focus on the failure of ductile metal structures, and
Chapter 5 examines a related topic on the perforation of metal tubes.
Bammann et al. in Chapter 1 develop an internal state variable type of
criterion specifically for numerical applications, which can be used to
predict the failure of ductile metal structures subjected to large dynamic
loads. These approaches are becoming increasingly possible for design
ers because of the increase in computing capability per unit cost and
other developments over the past 10 years since the First Symposium,
though they are not yet quite cheap enough and easy enough to use in
many non-military related industries. Homes et al. in Chapter 2 use a
simpler local damage model and assume that failure occurs when the
equivalent plastic strain reaches a critical failure strain that is a function
of the stress triaxiality.
An energy density theory is discussed in Chapter 3 for ductile beams
subjected to large dynamic loads. This criterion is developed for use
with theoretical and numerical formulations based on generalized
stresses. Ferron and Zeghloul review in Chapter 4 the topics of strain
localization and fracture in metal sheets and thin-walled structures,
mainly from a metal-forming viewpoint, but the ideas should have value
for future studies on structural failure. Stronge in Chapter 5 reports
on the indentation and perforation of metal tubes struck by a missile.
This is an area of increasing interest to designers because of the
requirement to assess the safety of many engineering systems from a
wide range of hazards.
Chapters 6-8 focus on the behaviour of non-metal structures
subjected to various large dynamic loads. Kindervater and Georgi in
Chapter 6 review the experimental literature on the energy absorption
and structural resistance of high-performance structures made from
Preface ix
composite materials, mainly from an aircraft crashworthiness perspec
tive, but their treatment contains important information for many other
areas. Haug and de Rouvray in Chapter 7 study the numerical
simulation and prediction of the crashworthy behaviour of structures
and components made from fibre-reinforced composite materials.
Particular emphasis is placed on the collision protection of automobiles,
but again the results are relevant to many other industries. Reid et al. in
Chapter 8 review recent studies on the dynamic response of cellular
structures and cellular materials. This article concentrates on the basic
mechanics and points out the importance of microbuckling and micro
inertia of the individual cells.
Yu in Chapter 9 explores the importance of material elasticity for the
behaviour of structures that are subjected to dynamic loads producing
large plastic strains.
McGregor et al. in Chapter 10 examine the impact performance of
aluminium structures, mainly from the viewpoint of the crashworthiness
of automobile structures. The principal objective of this study is to
provide data for the design of aluminium structures, and, for example,
the crushing and bending behaviour of various thin-walled open
cross-sections is examined and compared with the behaviour of similar
steel components.
Carney in Chapter 11 discusses the energy dissipation characteristics
of impact attenuation systems such as guardrail end protection and
crash cushions used for motorway safety applications in the United
States. The issues for the further development of these protection
systems are ventilated, and some suggestions made for further progress.
Finally, Chapter 12 returns to the failure of structural members, but
this time for the crushing, cutting and tearing of ships scantlings
associated with grounding damage. Analytical methods of analysis are
developed and simplified, and compared with the results of small-scale
experiments.
The contents of this book and the companion proceedings published
in special issues of the International Journal of Impact Engineering7 and
the International Journal of Mechanical Sciences8 are relevant to a wide
range of safety calculations, hazard assessments and energy absorbing
systems throughout engineering, as well as for developments in the field
of structural crashworthiness. The public is becoming increasingly
aware of safety and environmental issues as a result of several recent
accidents,910 and very often dynamic loads play an important role in
disasters. Further progress towards the optimization of engineering
structures and components, which leads to lighter structures and
vehicles, again increases the importance of dynamic loads and structural
