Study On The Prediction Of Stiffness Characteristics Of Rubber Matrix Composite Structure

Rubber matrix composite is a kind of important composites after resin,metal and ceramic matrix composites.Due to nonlinear and hyperelastic properties of rubber matrix,the composites have the characteristic of large deformation,and have great potential in the fields of aerospace,light construction,oil transportation pipe and so on.It is of great theoretical significance and engineering application value to study the stiffness characteristics of rubber matrix composites.This paper focuses on establishing the stiffness prediction models of 2D woven fabric rubber matrix composites and cord-rubber composites,and analysis of deformation behavior of 2D rectangular inlet bump and 3D axisymmetric inlet bump.The main research contents are summarized as following.(1)The stiffness prediction model of 2D woven fabric rubber matrix composites was established.According to fabric reinforced composites micro geometry parameters,lenticular cross section assumption adopted for fiber bundle,representative volume element(RVE)of 2D woven fabric composites was constructed.With Mooney-Rivlin strain energy function by two parameters to describe mechanical properties of rubber matrix,and periodic boundary conditions applied,simulations of uniaxial tension along fiber direction of 2D woven fabric rubber matrix composites were carried out in the finite element software.The results show that stress-strain curve in 5% strain of RVE can be linearly processed.The fabric reinforced rubber matrix composites with small deformation can be seen as orthotropic materials.The stress and strain field results can be achieved by finite element analysis,and engineering elastic constants of the composites can be obtained by further calculation.(2)The stiffness prediction model of cord-rubber composites was established.Uniaxial tensile experiments of rubber materials and cord-rubber composites were carried out,and three kinds of constitutive models of rubber materials were contrasted.The results show that Mooney-Rivlin model by two parameters is the most suitable model to describe mechanical properties of rubber materials in this paper.The anisotropic hyperelastic constitutive model of cord-rubber composites was proposed based on strain energy function.The stress-strain relation under uniaxial tension was derived,and the method to identify material parameters was given.UANISOHYPER_INV interface provided by ABAQUS was used to carry out application of the constitutive model.Simulation results agree well with experiment results,which verifies validity of the anisotropic hyperelastic constitutive model established in this paper.(3)The stiffness characteristics and influencing factors of 2D rectangular inlet bump and 3D axisymmetric inlet bump were studied.2D rectangular inlet bump model constructed,with 2D woven fabric rubber matrix composites,the deformation behavior of bump in different plane shapes was analyzed.The finite element model of 3D axisymmetric inlet bump was constructed according to the air bag structure of a particle separator.With cord-rubber composites,generatrix shape of the bump was obtained by simulation.Deformation shape of simulation agrees well with shape measured by schlieren technique,which proves the correctness of the finite element model.The deformation behavior simulations of the bump with different cord angles were carried out.The laws of the deformation height of the bump with different cord angles at the same air pressure,and the differences of the deformation shapes of the bump with different cord angles were investigated.The stiffness prediction models of two kinds of rubber matrix composites established in this paper,and analysis results of deformation behavior of 2D rectangular inlet bump and 3D axisymmetric inlet bump,lay a foundation for further design and optimization of bump structure made of rubber matrix composites.