Topology optimization of beam-column subjected to axial and transverse loads considering effects of buckling

Abstract

Steel beams with perforated web has been developed in order to increase the stiffness to weight ratio by placing holes in the web judiciously. Castellated beams (hexagonal openings in web) and cellular beams (circular openings in web) are examples of such beams. Use of topology optimization for designing such beams still remain a field of interest for generating design concept. The use of commercial optimization is rapidly increasing as it helps us to determine the optimal placement of material in design domain. This thesis investigates the application of topology optimization technique to design steel perforated I-section beams subjected to axial and transverse load. The approach used in this work is a Solid Isotropic Material with Penalization (SIMP). Optimization of beam was performed considering two loading conditions first one was uniformly istributed load and other considering a combination of axial compressive load and uniformly distributed load. Two different load cases linearstatic and geometric nonlinear case was considered and reduction in mass of optimized beam subjected to combination of axial compressive and niformly distributed load with linear load case was 21.24%. Further finite element analysis of optimized beams for different cases was done and were compared with non-optimized beams. The extension of topology optimization problem by including buckling constraints was performed along with linear buckling analysis of optimized beam. The comparison of non-optimized beam with optimized beam in terms of buckling eigenvalue was also carried out and results showed that the optimized design was less susceptible to buckling as compared to non-optimized beam. The tools used for performing topology optimization were Altair HyperWorks Optistruct, HyperMesh and HyperView. This work showed that topology optimization of beams result in lighter beams which also satisfied the yield load and displacement criteria for which the beams were designed.