Dynamic responses and failure analysis of C/SiC composite plates subjected high intensity acoustic loads

Thermal protection systems and hot structures of hypersonic vehicles include many composite plates. These structures are very sensitive to acoustic loads during cruise or re-entry flights and are destroyed easily. It is a vital challenge for the integrity and the durability of hypersonic vehicle plates. The C/SiC composite testing flat plates with thickness from 1 mm to 3 mm were chosen and many acoustic tests were carried out using a progressive wave tube facility. The four edges of these flat plates were completely fixed using fastening bolts. Responses of acceleration and strain of the C/SiC composite testing plates within 156-165 dB acoustic loads were obtained. The C/SiC composite testing plate with the thickness of 1 mm was destroyed rapidly subjected acoustic load with sound pressure level 168 dB. The failure plate was detected using the infrared nondestructive devices and the fracture surface was observed using SEM, then the failure modes of the testing plate were also achieved. The results are significant to optimum designs and anti-acoustic failure evaluation for high temperature material structures.