“…The key idea in these methods, which was introduced and detailed in [11], consists of formulating the plastic analysis problem using direct methods to limit analysis [18,19] and to integrate the analysis and design problems into a single mathematical problem. It was considered for smooth topology design in [11][12][13][14] and extended to discrete (i.e., 0-1) design in [16,17,20]. Although the discrete design is generally the primary goal, the smooth design problem is worthy of study as it is a component in many solution strategies for discrete design [16,21].…”