Rail clamps are mechanical components installed to fix the container crane to its lower members against wind blast or slip. Rail clamps should be designed to survive harsh wind loading conditions. In this study, a jaw structure, which is a part of a wedge-typed rail clamp, is optimized with respect to its strength under a severe wind loading condition. According to the classification of structural optimization, the structural optimization of a jaw is included in the category of shape optimization. Conventional structural optimization methods have difficulties in defining complex shape design variables and preventing mesh distortions. To overcome the difficulties, a metamodel using the Kriging interpolation method is introduced to replace the true response by an approximate one. This research presents the shape optimization of a jaw using iterative Kriging interpolation models and a simulated annealing algorithm. The new Kriging models are iteratively constructed by refining the former Kriging models. This process is continued until the convergence criteria are satisfied. The optimum results obtained by the suggested method are compared with those obtained by the DOE (design of experiments) and VT (variation technology) methods built in ANSYS WORKBENCH.

Bumpers are structural components installed to reduce physical damage to the front and rear ends of a passenger motor vehicle from low-speed collisions. Damage and protection assessments are the commonly used design criteria in bumper design. For damage assessment, the relative displacements representing stiffness performance are defined and examined. At the protodesign stage for a new car, finite element (FE) analysis is often utilized to predict the stiffness of a bumper. However, conventional bumper analysis through FEM outputs a constant stiffness even though the stiffness has some distribution due to uncertainties. In this research, the uncertainties are assumed to be the tolerances of thicknesses. Under this uncertain condition, the displacements representing stiffness are calculated by approximate statistics and by worst-case analysis. Then, a robust design is determined by design of experiments (DOE) using the orthogonal array strategy to find the design having a minimum weight of bumper within the stiffness constraints. In this research, the thicknesses of the inner beam, outer beam, and stay are treated as design variables. The robust design procedure for a bumper, considering the uncertain thicknesses, is presented.