- Email: [email protected]
Energy absorption of structures and materials
ARTICLE IN PRESS
International Journal of Impact Engineering 30 (2004) 881–882
Book review Energy absorption of structures and materials Guoxing Lu and Tongxi Yu
I am pleased to see that a very useful book is getting into the hands of engineers in the industry and researchers all over the world. The area of crashworthiness engineering has enjoyed an unprecedented growth over the past 2 decades. A number of us, including the two distinguished authors of this book, participated very actively in the developments of various methods and solutions applicable to the main theme of the book. The authors were able to make a correct selection of vast material scattered over conference proceedings and leading international journals and arrange into 12 self-contained chapters. A quick review of the list of references reveals that about 337 publications are listed, out of which almost 50 were published in the International Journal of Impact Engineering and another 50 in the International Journal of Mechanical Sciences. It is therefore quite natural that the review of this book is published in IJIE. I carefully went over most of the papers listed and I have concluded that those represent the main contributions to the area and the authors should be congratulated for making such a wise selection. The book presents various types of structures as a sequence of new boundary value problems each solved individually with some but not extensive experimental verification. Such an arrangement of the material will be very helpful for a reader who is looking in the book for a solution of a particular problem. At the same time, various methods and assumptions are repeated in the above particular solutions and one would wonder if a fundamental monograph like this should not be written in a different way. What I mean here would be to characterize materials, then go into the local equilibrium formulation, and linear and non-linear geometry of the structure. Then, depending on the problem, present some very general methods of solutions that are for example the principal of virtual work, upper bound theorem in plasticity, steady-state solutions for propagating plasticity, postulate of minimum crushing force, distinction between periodic (progressive folding) and nonperiodic (bending) formulation, etc. Such a presentation of the material would be more appropriate for graduate and doctoral students as well as research personnel in the industry because they would be able to generate similar solutions to other related problems but not necessarily those covered by the authors. Chapter 8 about plastic deformation with ductile tearing and Chapter 10 on cellular materials are very interesting but lack some firm theoretical foundation. There has recently been a lot of progress in understanding uniaxial and multiaxial behavior of aluminum foams and honeycombs as well as formulations of the initiation and propagation of cracks. Those newest results are not included in the book. On one hand, this is understandable because clear boundaries should always be set on the content of any book. On the other hand, the reader is left with the feeling that this is doi:10.1016/j.ijimpeng.2003.12.004
ARTICLE IN PRESS 882
Book review / International Journal of Impact Engineering 30 (2004) 881–882
the state-of-the-art, which it is not. For example, too much emphasis is put on lateral deformation of a system of rings, tubes, and honeycombs, which are of little importance in practical applications. At the same time, insufficient coverage is presented on axial deformation of similar structures and the possible coupling of stress components in this highly unisotropic media. Chapter 11 on composite tubes is a nice surprise because the problem is difficult and the authors managed to convey the main ideas and show the main difficulties. Talking about difficulties, one of the criticisms of the book would be that many methods and solutions are presented by the authors without giving their limitations or without pointing out what the shortcomings are in terms of formulation and solution method. For example, Chris Calladine was one who quite frequently raised questions about the correctness of various postulate and assumptions and his contribution in this regard cannot be over emphasized. One would expect that in a book that summarizes a contribution of an entire field during the past 20 years those questions and critique would be raised more openly. Crashworthiness engineering is relying more and more on numerical methods. Analytical solutions are in a way considered old fashioned and the industry is believing in and extensively using commercial codes such as PAM CRASH, LS-DYNA, ABAQUS, etc. This is an entirely different way of looking at structures and I think it was absolutely correct that the authors have not included any of these into their book. At the same time there is and there will be an urgent need to summarize the advances of the numerical method in solving crashworthiness and energy absorption problems indicating their limitations as well as advantages. Despite the above critical remarks that most probably would only be noticed by someone who actively participates in the development of the entire field of crashworthiness, the overall rating of the book should be very high. This book could be considered a sequel to the previous book entitled ‘‘Dynamic Models for Structural Plasticity’’ by W. J. Stronge and T. Yu in which a lot of fundamental developments and background material were thoroughly discussed. In summary, I would recommend that the book be within reach of every person working in the area of energy absorption and crashworthiness engineering.
T Wierzbicki Department of Ocean Engineering Room 5-218 Massachusetts Institute of Technology Cambridge, MA 02139-4307, USA E-mail address: [email protected]
International Journal of Impact Engineering 30 (2004) 881–882
Book review Energy absorption of structures and materials Guoxing Lu and Tongxi Yu
I am pleased to see that a very useful book is getting into the hands of engineers in the industry and researchers all over the world. The area of crashworthiness engineering has enjoyed an unprecedented growth over the past 2 decades. A number of us, including the two distinguished authors of this book, participated very actively in the developments of various methods and solutions applicable to the main theme of the book. The authors were able to make a correct selection of vast material scattered over conference proceedings and leading international journals and arrange into 12 self-contained chapters. A quick review of the list of references reveals that about 337 publications are listed, out of which almost 50 were published in the International Journal of Impact Engineering and another 50 in the International Journal of Mechanical Sciences. It is therefore quite natural that the review of this book is published in IJIE. I carefully went over most of the papers listed and I have concluded that those represent the main contributions to the area and the authors should be congratulated for making such a wise selection. The book presents various types of structures as a sequence of new boundary value problems each solved individually with some but not extensive experimental verification. Such an arrangement of the material will be very helpful for a reader who is looking in the book for a solution of a particular problem. At the same time, various methods and assumptions are repeated in the above particular solutions and one would wonder if a fundamental monograph like this should not be written in a different way. What I mean here would be to characterize materials, then go into the local equilibrium formulation, and linear and non-linear geometry of the structure. Then, depending on the problem, present some very general methods of solutions that are for example the principal of virtual work, upper bound theorem in plasticity, steady-state solutions for propagating plasticity, postulate of minimum crushing force, distinction between periodic (progressive folding) and nonperiodic (bending) formulation, etc. Such a presentation of the material would be more appropriate for graduate and doctoral students as well as research personnel in the industry because they would be able to generate similar solutions to other related problems but not necessarily those covered by the authors. Chapter 8 about plastic deformation with ductile tearing and Chapter 10 on cellular materials are very interesting but lack some firm theoretical foundation. There has recently been a lot of progress in understanding uniaxial and multiaxial behavior of aluminum foams and honeycombs as well as formulations of the initiation and propagation of cracks. Those newest results are not included in the book. On one hand, this is understandable because clear boundaries should always be set on the content of any book. On the other hand, the reader is left with the feeling that this is doi:10.1016/j.ijimpeng.2003.12.004
ARTICLE IN PRESS 882
Book review / International Journal of Impact Engineering 30 (2004) 881–882
the state-of-the-art, which it is not. For example, too much emphasis is put on lateral deformation of a system of rings, tubes, and honeycombs, which are of little importance in practical applications. At the same time, insufficient coverage is presented on axial deformation of similar structures and the possible coupling of stress components in this highly unisotropic media. Chapter 11 on composite tubes is a nice surprise because the problem is difficult and the authors managed to convey the main ideas and show the main difficulties. Talking about difficulties, one of the criticisms of the book would be that many methods and solutions are presented by the authors without giving their limitations or without pointing out what the shortcomings are in terms of formulation and solution method. For example, Chris Calladine was one who quite frequently raised questions about the correctness of various postulate and assumptions and his contribution in this regard cannot be over emphasized. One would expect that in a book that summarizes a contribution of an entire field during the past 20 years those questions and critique would be raised more openly. Crashworthiness engineering is relying more and more on numerical methods. Analytical solutions are in a way considered old fashioned and the industry is believing in and extensively using commercial codes such as PAM CRASH, LS-DYNA, ABAQUS, etc. This is an entirely different way of looking at structures and I think it was absolutely correct that the authors have not included any of these into their book. At the same time there is and there will be an urgent need to summarize the advances of the numerical method in solving crashworthiness and energy absorption problems indicating their limitations as well as advantages. Despite the above critical remarks that most probably would only be noticed by someone who actively participates in the development of the entire field of crashworthiness, the overall rating of the book should be very high. This book could be considered a sequel to the previous book entitled ‘‘Dynamic Models for Structural Plasticity’’ by W. J. Stronge and T. Yu in which a lot of fundamental developments and background material were thoroughly discussed. In summary, I would recommend that the book be within reach of every person working in the area of energy absorption and crashworthiness engineering.
T Wierzbicki Department of Ocean Engineering Room 5-218 Massachusetts Institute of Technology Cambridge, MA 02139-4307, USA E-mail address: [email protected]