Optimal impact resistance design for RC slabs

In this study, an attempt was made to develop a useful design support system for RC slabs by combining a 3-D nonlinear dynamic FEM newly developed in our laboratory for impact failure behavior and an immune algorithm (IA) with which multiple quasi-optimum solutions can be obtained. For the analysis of impact failure behavior, layered nonlinear FEM models with thin plate bending elements, and three-dimensional elastoplastic FEM models with 8-node isoparametric hexahedral elements were used. First, an existing IA was modified to make it suitable for RC slab designing, and both genetic and immune algorithms were applied to optimization problems with multiple optimum solutions, as well as quasi-optimization problems with multiple maximum values. By comparing the above two approaches, the usefulness of the IA for design problems with discrete parameters was verified. Next, indices for evaluating impact resistance were discussed, and design simulation was conducted based on the indices by combining the layered nonlinear FEM and the IA. From the results obtained, the precision and usefulness of the IA-based design support system are discussed. For obtaining a more practical design support system, shear reinforcement was taken into account by combining the IA with the three- dimensional elastoplastic FEM. Furthermore, the effectiveness and future potential of the design support system were confirmed by investigating the effect of introducing a database of design plans.