Secondary Creep Response of Hand Lay-Up GRP Composites
Glass Reinforced Plastics (GRP) composite load bearing components are now in common use, quite often at temperatures above the ambient, where creep behaviour may be significant, as in pressurized industrial containers. This is especially true of those composites produced by the Hand Lay-Up Contact Moulding Technique, which may possess some production defects. Creep in an engineering material depends on the temperature as well as the stress level within the material. This paper examines the Secondary Creep Strain and Strain Rate of Hand Lay-Up GRP composites subjects to uniaxial stress at an elevated temperature. Empirical expressions are sought to relate Creep Strain Rate and Stress Level with time at the Secondary Creep stage. The Secondary Creep Strain Rate at a given stress level is found to be approximately constant and increases with the stress.