b)Triaxial material tests have been made on epoxy cast thin-walled cylinderical samples when they are in plane stress state where there are six principal stress ratios (1=0, 1=0.5, 1:0.96, 1: -1, 1: 0.38, 1:-0.155) .

• 对环氧树脂浇注体薄壁园管试件；在平面应力状态下的六种主应力比(1:0;1:O.；5;1:0