ABSTRACT
The single most compelling reason for using the direct stiffness method is that suitable computer codes are so well developed that it is a natural step to include non-linear analysis in their repertoire. In this chapter three distinct types of problem are discussed. The analysis of tension structures leads to the shape finding and design of net and fabric structures. The calculation of small displacement elastic critical loads (and/or bifurcation points) and mode shapes. This is a relatively small extension of the elastic analysis. The tracing of the whole equilibrium path of a structure through snap-through phenomena. Tension structures are particularly amenable to computer design in that the computer can be used in a creative sense in aiding the architect or engineer in the selection of a desired structural shape while starting with only a plan.
