LONG-TERM OPEN HOLE COMPRESSION STRENGTH OF CFRP LAMINATES BASED ON STRAIN INVARIANT FAILURE THEORY

摘要

This paper deals with the prediction of long term strength of CFRP structure components based on the combined method of the strain invariant failure theory (SIFT) and the accelerated testing methodology (ATM) developed by Tsai and others. The time-temperature dependent master curves of SIFT critical parameters were constructed by tension and compression tests for the longitudinal and transverse directions of unidirectional CFRP under various temperatures based on the time-temperature superposition principle which holds for the viscoelastic modulus of matrix resin. The long term open hole compression strength of the quasi-isotropic CFRP laminates was predicted using the master curves of SIFT critical parameters based on SIFT/ATM combined method and structural stress and strain analysis by finite element method. The applicability of SIFT/ATM combined method to predict the long term strength of CFRP structures was experimentally confirmed.