基于横观各向同性超弹性理论的短纤维增强橡胶本构模型的建立与应用

Establishment and application of short fiber reinforced rubber constitutive model based on transversely isotropic hyperelastic theory

提出了一种能够表征短纤维增强橡胶的横观各向同性超弹性本构模型,并结合试验体系,对其在数值分析中的应用方法和效果进行了研究。基于连续介质力学理论,建立了横观各向同性材料的应变能函数,推导得到不同变形形式下的应力应变关系,给出材料参数辨识试验方法,并成功应用于某短纤维增强橡胶测试中,得到表征其超弹性特性的相关材料参数。利用有限元软件ANSYS对不同纤维排布方向的单轴拉伸和平行纤维方向的平面拉伸进行仿真计算,并对比相应试验数据,以验证材料参数的可靠性。最后基于已验证的本构模型,建立了某铣槽装备减振环仿真模型,并对其进行了校核计算。研究结果表明,本文提出的本构模型能够有效表征短纤维增强橡胶的静态力学特性并且方便嵌入现有的有限元软件中,具有材料参数少、测试简便和结果准确等特点,工程实用性强。

A transversely isotropic hyperelastic constitutive model that characterizes the behavior of short fiber reinforced rubber is proposed, combining with test system, the method and effect of its application in numerical analysis are studied. Based on the theory of continuum mechanics,a strain energy function of transversely isotropic hyperelastic material is established, from that stress-strain relationships under different deformation forms are inferred, then method to test and identify material parameters is proposed and successfully applied in testing a short fiber reinforced rubber to obtain the material parameters related to its hyperelastic characteristics. Using ANSYS software, simulations of uniaxial tension with different fiber directions and plane tension with parallel fiber direction are carried out, comparing with corresponding test data, to verify the reliability of material parameters. Finally,the verified constitutive model is used in checking calculation of the vibration isolator in a milling equipment as its engineering application. The research result shows that the proposed constitutive model can effectively characterize the static mechanical properties of short fiber reinforced rubber,it＇s convenient to implement in existing finite element software and engineering practical with characteristics such as less but easy to be identified material parameters,and relatively accurate result.