The Stress Transfer Between Fiber And Matrix Was Analyzed By Mesomechanical Model

The strength of fiber composites has always been a research direction of people,the correct and effective prediction of the strength of fiber composites,first of all,we should understand the fiber stress distribution.Based on the study of the stress transfer between the fiber and the matrix,the stress distribution on the fiber is extended.The three phase structure micromechanical model with fiber,matrix and interface layer and the two phase structure micromechanical model with fiber random distribution were established respectively.According to the different micromechanics model,the stress transfer process is analyzed and the stress distribution on the fiber is predicted.In this paper,Eshelby's equivalent inclusion theory,Mori-Tanaka method and shear lag theory are used to derive the analytical formula of stress distribution on the fiber.In this paper,Eshelby's equivalent inclusion theory and Mori-Tanaka method are used to calculate the effective elastic modulus of the equivalent fiber(equivalent between the fiber and the interface layer).At the same time,the factors affecting the stress distribution on the fiber are also discussed.In addition,because the mechanical properties of different interface layers will have an impact on the mechanical parameters of the equivalent fiber phase,this paper also considers the impact of different interface mechanical properties parameters on the interface transfer stress.The effect of interface properties on stress transfer is investigated.Based on the theory of shear lag and the basic formula of elastic mechanics,the stress distribution of fiber in random orientation is deduced.Based on the theory of shear lag,the stress transfer process between fiber and matrix is analyzed,and the stress distribution expression under random orientation of fiber is derived.The effects of fiber aspect ratio and volume fraction on the stress distribution were also investigated.