Weight minimization of truss structures using an improved Harris hawks optimization algorithm

A methodology for discrete parametric optimization of space steel frames based on a metaheuristic job search inspired strategy has been developed. The paper considers minimizing the weight of frame structures made of bars with closed cross-sections, taking into account active constraints on overall stability, including the stability of individual bars, stresses and displacements. The search is carried out on the sets of admissible options for the cross-sections of the bars. Job search inspired strategy does not require the introduction of penalty functions when taking into account task constraints. Previously completed developments on the use of this strategy in the optimization of flat frames envisaged the introduction of small fictitious forces and the implementation of the iterative process of calculating the object from the deformed state to assess the degree of dissatisfaction with the overall stability condition. In the paper, this issue is solved for space frames based on LDLT decomposition of the tangent stiffness matrix of the finite element model of the structure. The auxiliary function of the goal uses the values of the elements of the diagonal matrix obtained from this decomposition. This approach provides an efficient stability test without directly considering the generalized eigenvalue problem for matrices. The performance of the proposed algorithm is illustrated using the example of optimization of a console made of round pipes.

Igor Serpik

Papers

Job Search Inspired Optimization of Space Steel Frames with Overall Stability Constraints