LONGITUDINAL THERMAL STRESS/STRAIN ANALYSIS FOR CARBON FIBER COMPOSITE

Xiao Yao, Li Shulin, Zhang Tiejun, Yin Junjie, Zhang Xianhang

ABSTRACT: Three different models were established to study thermal stress/strain of composite. Conventional lamellae model was simple and easy, but its accuracy was lower. Modified micro-mechanical model came from micromechanics. The temperature dependence of thermal expansion coefficient and orthotropic property of fiber were considered in this model, and the numerical result was agreed with finite element model. Composite thermal stress/strain under different temperature conditions ( 40 C 、 55 C 、 70 C) were calculated by different models. The result indicated that thermal stress/strain of fiber and matrix increase almost linearly with increasing temperature. The calculation results of random and regularly spaced multi-fiber distribution model were shown that regularly spaced model could reduce stress range of fiber or matrix stress, reduce stress concentration, and avoid matrix cracking and interfacial deboning.

Keywords: Composite, thermal stress/strain, micro-mechanics, finite element model