Mechanical properties and operational damage evaluation of CSM composites by destructive and non-destructive techniques

摘要

The damage parameter D expresses the effective density of micro-cracks, cavities and any other internal defect existing in a material. In the NDT methods of ultrasounds the change of ultrasonic waves' intensity is expressed by their attenuation coefficient. Based on this quantity, an improved technique by which one can simply and with adequate sensitivity and accuracy determine the damage of materials has been introduced. Also, in this study some damaging effects induced by creep loading under normal ambient conditions in CSM fibre reinforced resin composites were investigated by means of a basic type experimental approaching technique which is based on the influence of the creep-induced damaging effect on some relevant mechanical parameters such as elastic modulus and fracture stress. Finally, an experimental and theoretical study of certain static and dynamic properties of CSM resin composites through tensile and vibrations tests was carried out in order to determine elastic modulus, fracture stress, storage and loss moduli, to investigate the influence of parameters such as filler content.