Mechanical properties of glass fiber reinforced plastics of epoxy resin is experimentally investigated at 77 K and at room temperature. Tensile or shear load is applied to a cylindrical specimen, and the stress strain curves and the fracture stresses are determined. The compressive tests are conducted by using plate specimen. Elastic constants and fracture stresses of the unidirectionally reinforced plastics at 77 K are larger than those at room temperature. The deformation behavior shows more linearity at 77 K than at room temperature. When shear load is applied to the laminated specimens with symmetric cross ply, brittle fracture occurs at 77 K by delaminations and cracks in directions parallel to the fiber and plastic deforamtion occurs at room temperature. When tensile load is applied to laminated specimens with symmetric angle ply, the fracture stresses at 77 K are larger than those at room temperature except for the specimen with ply angle of 45 degree. For ply angle of 45 degree the fracture stresses at 77 K are smaller than that at room temperature. As to the fracture mode, the cracking parallel to the fiber is dominant for large ply angle.
抄録全体を表示