A Non-orthogonal Constitutive Model And Forming Simulation For Woven Composites Including Biaxial Tensile Coupling

New material is an important sign of the new technological revolution.Advanced high-strength woven composites have been widely used in aerospace,wind power,boats and cars and other fields.For further application of woven composites in various industries,composite materials technology and processes are booming.However,the high costs,low productivity,the immature technologies and other issues have been hampering woven composites’ applications in high-volume production.Therefore,this article concentrates on constitutive modeling and numerical simulation of woven composites,and carried out a systematic and thorough study.In this paper,through uniaxial tensile,bias-extension,biaxial tensile and picture frame tests,basic mechanical data for carbon woven fabric was obtained.Based on continuum mechanics,the effect of biaxial behavior was introduced into a previously developed non-orthogonal constitutive model of woven composites fabric,and a method for determining the model parameters was given.By compiling a user material subroutine UMAT of ABAQUS/Standard,the new material model was successfully embedded into the existing finite element software.And by fitting the result curves of uniaxial tensile,biasextension and biaxial tensile tests,the model parameters were determined.By numerical simulations of biaxial tensile test and double dome forming,and then comparing the results of tests and numerical simulations,the reliability of the developed model was verified.This model can characterize the anisotropic non-orthogonal mechanical property of composites fabric caused by large deformation more efficiently.Finally,hemispherical stamping of composites fabric under different binder force was simulated using the developed biaxial coupled model.The predicted numerical results were compared with experimental data,and the correctness of the model was verified.By comparison of boundary profiles and shear angle distributions under three different binder forces,the influences of binder force on composites fabric forming was studied.The appropriate increase in binder force can be beneficial for reducing fabric folding during forming.