Tension Structures, Second edition delivers a unique coverage of the topic of tension structures ranging from a variety of pre-stressed cable net and fabric roofing forms to suspension bridge cables. The emphasis is on finding minimum energy forms of these structures by analogy to nature.
Tension Structures, Second edition:
• features a number of projects detailing structural form and behaviour of tension structures
• offers an exclusive perspective that brings together fabric and cable structures, suspension bridge cables, and rigid structural forms, such as arches and shells
• provides unique insights into numerical modelling of cable and fabric structures
• includes brand new sections on modelling of suspension bridge cables and demonstrates its relevance to conceptual design of arch structures
• presents the latest approaches to patterning of fabric structures
As a permanent fixture of modern architecture, tension structures demonstrate their potential for creating aesthetically pleasing art forms and offer wonderful design opportunities that arise from their ability to span large distances with elegance and structural efficiency.
Tension Structures, Second edition compiles a vast amount of knowledge while providing an accessible entry to a rather specialised field. The mathematical expositions are set at an undergraduate level and, wherever possible, non-mathematical language is used to aid the understanding of fundamental concepts.
The book will be of interest to researchers studying tension structures, engineering and architectural students, practising civil and structural engineers, architects, and scientists developing computational methodologies for non-linear problems in areas other than civil engineering.
"In this edition, readers are benefited by the results of the latest research achievements in understanding the concept of the soap-film analogy in form-finding of fabric membranes. The key to tension structures - form finding, is running throughout the book. This is unlocked by the author in terms of conceptual design issues, as well as the use of principles observed by nature.
The book is without no doubt a useful tool for researchers, architects, civil and structural engineers and students, working on tension structures. In addition, it serves as an aid in developing computational methodologies for non-linear problems."
Yancheng Cai, University of Hong Kong, P.R.China
"Though just 200 pages, it is hard in this short review to describe this book’s masterful exposition; no complexity is glossed over.
The essential difference between what might be termed normal structures and tension structures is that the change of shape under loading is fundamental to the process of stress analysis. The copiously illustrated introductory chapter stresses this point, and clearly sets out all the ways tension structures may be encountered, together with the essential characteristics of each type.
One cannot pretend that the structural analysis of these structures is straightforward, and due to the lack of explicit solutions to the governing equations, various types of iterative numerical methods are required. An essential step for tension structures, given defined boundary conditions and an initial shape, is to find the final shape of the loaded structure; this is called form-finding. The second chapter is devoted to the various approaches to this essential step.
Over several following chapters Professor Lewis then outlines the various options for structural analysis. Mathematical basics are outlined, all clarified by diagrams. An intermediate summary chapter is called ‘Cable roof structures. Case studies.’ Here a number of common types of cable structures are presented, clarified by examples using computed results and clear diagrams. These are backed up with graphs showing the variation in results between experimental and computed results. In preparation for the chapter’s conclusions, a number of studies are given that examine the effect of geometric construction errors. The ‘Conclusions’ note that ‘tension structures have a remarkable ability to accommodate loads and relieve stresses,’ but that ‘errors in cable lengths can lead to a large variation in the tension field.’ This is followed by a number of words of practical wisdom.
One of the most fascinating chapters of the book is entitled ‘Tension cables in suspension bridges.’ Here the effect of departing from commonly used simplifying assumptions, such as inextensible main cables, weightless cables and hangers and a uniform deck load, is carefully explored. The mathematical derivations are accompanied by helpful diagrams. The chapter ends with words of caution about trying to make a suspension bridge follow a desired shape – dictated form – which clearly violate engineering realities."