Basic Concepts of the Stiffness Method

Abstract

The underlying philosophy of the stiffness method was informally introduced in chapter 1 and it is now appropriate to examine the fundamental principles which form the basis of what is known as the stiffness or displacement method of structural analysis. The method is applicable to all classes of structure and while particular details may vary in different applications, the basic concepts remain the same. The method begins by regarding the structure in the manner in which it has already been defined, that is as a collection of elements connected together at node points. In response to certain loads, generally at the nodes but not necessarily so, the structure will displace and the displaced shape can be defined by the collective terms describing the displacements at the nodes.