Abstract
This paper presents a design optimization of a concrete beam subjected to blast loading due to nuclear explosion. It focuses on sizing optimization problem of a concrete beam having elastic foundation and fixed ends. In the formulation of the optimization problem, the objective function is to minimize the maximum existing displacement. The design variables of the optimization problem are the depths of the concrete beam. The constraints are the concrete beam mass, the derivative of the depth and the plastic strain. A MATLAB code has been developed to obtain the pressure time history. This code is linked to the finite element software ANSYS to determine the displacement time history , strains, stresses and the best cross section shape of the concrete beam.