Stress Analysis of Elastic-Plastic Interphase
for Model Compostites
Jia Purong  Jiao Guiqong
(Dept.of Engn. Mech., Northwestern Polytechnical University, Xi'an, 710072)

Abstract: The interphase generated by the fibre reinforcing elastic-plastic matrix is possessed of elastic-plastic mechanical behaviour. Considering the plastic deformation of general material to abide by the power-law hardening, the paper conductsanalyses of deformation and stress for the interphase of model composites underelastic and plastic hardening conditions. Take the fibre pull-out test for studying model, and divide the interface into elastic zone and plastic zone. By employing the shear lag theory, the basic equations of interfacial mechanics for the elastic zone and the plastic zone are established respectively. Displacement functions selected reasonably must meet the basic equations and the end condition of the fibre. And by the functions the interfacial shear stresses in elastic and plastic zones are solved. The relatioship between mean interfacial shear stress and the fibre length in the matrix is deduced. The problem of elastic plastic interface failure is discussed at last.
Keywords: model composite, elastic-plastic interphase, displacement function, interfacial shear stress.