Optimal Layout of Trusses

Abstract

In Section 3.2b we discussed optimal plastic design of a truss of given layout. The notations and results of that section will now be used in the discussion of the following problem. A plane truss is to transmit the given load P to a given rigid foundation, which is indicated by shading in Fig. 5.1. The bars of the truss are to be made from a rigid, perfectly plastic material with tensile and compressive yield limits ±σ₀. The given load is to represent the load-carrying capacity of the truss, and the total volume of the bars of the truss is to be minimized. Note that the choice of the layout of the truss is left to the designer, except that there must be a joint at the given point of application of the load, and that joints on the foundation arc, wich represents the surface of the rigid foundation, are restrained from moving.