SHAPE OPTIMAL-DESIGN OF ELASTIC SPACE FRAMES WITH NONLINEAR RESPONSE

This paper describes an approach to shape optimal design of elastic sp ace frames with kinematically non-linear response. A space frame struc ture is treated as to be assembled from several frame design elements each of them being defined as a skeleton lying on a rational Bezier pa tch. The design variables may influence the control points of each pat ch and the cross-sectional quantities of beam elements. Highly accurat e beam finite elements are employed based on a modified formulation of the beam element proposed by Jelenic and Saje. The modified element i s able to account for arbitrary initial curvature and it fits nicely i nto the context of both the proposed design element technique-and the optimization process. The formulation of the shape optimal design prob lem in form of non-linear mathematical programming problem and its sol ution by employing gradient-based methods of mathematical programming are discussed briefly. The theory is illustrated in detail with three numerical examples. (C) 1998 John Wiley & Sons, Ltd.