VISCOELASTIC CREEP AND RELAXATION IN LAMINATED COMPOSITES

摘要

An extensive series of creep tests were made on bulk epoxy specimens (Narmco 1004) and on three types of laminated specimens made from a composite (Modmor II 5206) with this epoxy as its matrix. Tests were made at a wide range of temperatures and stresses. The resulting laminate creep curves were compared with calculations employing a modified version of a computer program developed in connection with earlier work on this project. An equation was developed that describes the epoxy as a thermorheologically simple substance, for use in non-isothermal viscoelastic calculations. The computer program was extended to perform such calculations and used to compute the stresses in a balanced laminate assembled at 300F and cooled to 64F.