Papers by Author: Sung Yong Yang

Abstract: We surveyed literature and proposed a procedure to identify the fatigue properties from the Brinell hardness and Young’s modulus. And we developed a parameter similar to the S.W.T. parameter with the Brinell hardness and Young’s modulus. Using the parameter and finite element analyses, we evaluated fatigue lives of four kinds of welded joints. The predicted results are in a good agreement with experimental results.

Abstract: Mechanical behavior of CFRP (Carbon Fiber Reinforced Polymer) containing Ni-Ti shape memory alloy (SMA) is investigated by experimental methods. Tensile and bending fracture tests were conducted to examine the strength of the composite for various volume fractions of the SMA. Charpy impact test was used to study the toughness of the SMA/CFRP hybrid composite. Finite element analysis was carried out for interface failure in bending test.

Abstract: Mechanical behavior and fracture process of weld specimens were analyzed by finite element method. Three-dimensional butt-weld specimen was modeled by two-dimensional approaches. Welding residual stress in the models was obtained by carrying out thermo-mechanical calculation. To take into account straight boundary lines of real weld specimen, the finite element model was constructed by using an iterative method. Cohesive zone method was applied to analyze fatigue behavior of the models.