Papers by Author: J.J. Jung

Abstract: To optimize a connecting rod satisfying fatigue life, metamodel-based design optimization is proposed. To approximately predict both volume and fatigue life of connecting rod, kriging metamodel is constructed based on maximin eigenvalue sampling. Fatigue analysis is accomplished for the calculation of fatigue life. The results of metamodel-based design optimization are compared with those of classical optimization. The advantages of metamodel-based optimization are discussed.

Abstract: Nonlinear analysis of anisotropic structures is described by using Hill's yield criterion that anisotropic yield contour is assumed to be retained its shape during the hardening process. Nonlinear constitutive equation of anisotropic material is derived using plastic potential concept. Linear strain hardening model is utilized and forward Euler method is employed as a stress integration method. Newton-Raphson method is implemented for numerical nonlinear analysis. Direct differentiation method differentiating directly the equilibrium equation with respect to design variables is applied to design sensitivity analysis of nonlinear anisotropic plate. The results of design sensitivity analysis are compared with those of finite difference method to verify the accuracy. Optimization is accomplished for a rectangular plate using evaluated sensitivity coefficients.