Optimum Layup Design of the GFRP Composite Bogie Frame for Urban Subway Trains

초록

In this study, the stacking sequences and number of plies of the GFRP composite bogie frame for an urban subway train have been optimized. The design variables were the discrete ply angles such as 0o, ？b45o, and 90o and the number of plies in skin layers. The objective of this study is to minimize the weight of the GFRP composite bogie frame under the fatigue strength and the maximum displacement constraints. In addition to the previous constrains, the design rules not only to preclude or reduce the undesirable stress coupling effects but also to depress the interlaminar stress components were imposed. The fatigue strength was assessed using Goodman diagram obtained from the specimen fatigue test. From the optimization results, the thickness of the skin was reduced up to 1.5mm (form the original thickness 15mm to the optimized thickness 13.5mm) the corresponding to 10% of the original skin thickness. The optimum stacking sequence was [0/(904/-45/45)2/0/904/？b45/03/？b45/-45/45/902]s.