# Understanding Structural Analysis Third Edition

## Understanding Structural Analysis Third Edition

This book is aimed at the identification oJ the fundamental princiPles of
structural analysis together with the develoPment oI a sound understanding
of structural behaviour. This combination leads to the ability to arrive at
a numerical solution.
Using a series of structural diagrams as a visual lanSuage ol
structural behaviour that can be understood with the minimum oJ textual
comments, the book aims to develop a qualitative understanding of the
response of the structure to load. It is ideally suited to under8raduates
studying indeterminate framed structures as Part of a core course in civil
or structural engineerinS' but it is also suitable, because of its
qualitative approach, for students of architecture and building technology.
The book is in two parts. Part I' the first lour chapters, deals with
the development ol qualitative skiils; that is' the ability to Produce a
non-numerical solution to the loaded line-dia8ram ol a structure. It is
considered that the ability to arrive at the qualitative solution to framed
structures is a significantly imlortant component of the overall
understanding of structural behaviour.
Part II deals with current methods of structural analysis using the
diagrammatic format to which the student has become accustomed.
The need lor the developrrent of qualitative skills increases with the
increasing use of the computer in design offices. In the near future, the
computer will replace the majority ol analysis and structural desiSn
calculations. Unfortunately, this will also have the elfect of eliminating
much of the experience and consequent understanding gained by the student
and trainee engineer.

The subject of this book is the behaviour and analysis of statically
indeterminate structures. However, this first chapter reviews the
behaviour of deterninate structures, a thorough understanding of which
is essential before the topic of indeterminacy can be tackled. The text
assumes a basic knowled8e of mechanics including an understandin8 of
the principles of overall equilibrium, bending moments, shear and axial
forces.
It is possible to analyse determinate structures by consideration of
equilibrium - in general terms, the application ol force and moment
eouarions v 1 O. d = 0 and lt = 0.
With most real structures, this is not possible as the presence ol
redundant members (secondary load paths) makes it necessary to consider
relative member delormation beJore a solution of the structure can be
attained. The number of unknowns which cannot be lound Jrom equilibrium
considerations is known as the degree oJ statical indeterminacy.
The design oJ engineering structures usually starts from a need to
sostain loads. Initially though, it requires an understanding ol the way in
which a proposed system of members can provide the required support, and
how it will deform.
It is, however, clear that an understandin8 oi the behaviour of
statically indeterninate systems is based upon a thorou8h appreciation
cf deterrirrate systems.
This chapter develops the relationship between load and delormation for
a range of structures which are amenable to solution by the application of
equilibrium alone.