Understanding the factors affecting the compressive testing of unidirectional carbon fibre composites

An investigation was conducted to establish the effects of specimen preparation and configuration on the measured compressive strength of unidirectional carbon fibre. The compressive strength was determined through ASTM D 695 M [ASTM D 695 M, Standard test method for compressive properties of rigid plastics. http://www.astm.org] test method. Specimens conforming to this standard were produced with different thickness, edge and surface preparation. Optical and electron (SEM) microscopical techniques were used to assess initiation of failure and to quantify the damage encountered by the compressive test specimen. The findings correlated well with the mechanical test results, additionally; from the mechanical testing there was significant evidence to suggest that the failure mechanism is dependent upon the quality of the preparation of the test specimen.