低模高弹体泊松比试验测试方法

Test method of Poisson's ratio for low modulus elastomer

[目的]在轴向承载时,低模高弹体存在侧向形变大、均匀性差等问题,常规电阻式应变测试方法难以准确获取材料的泊松比。为了消除试件侧向变形的不均匀性影响,准确获取高分子材料的泊松比值,[方法]基于弹性力学理论,推导了圆柱形低模高弹体在侧向刚性约束时的压缩模量、弹性模量与泊松比的表达式,建立了试验的理论模型。在理论分析的基础上,提出了由钢制套筒侧向约束轴向加载的泊松比测试方案,并开展了天然橡胶及HW-050型浮力材料的钢制套筒约束试验研究,验证了该试验测试方法的有效性及合理性。最后利用ABAQUS软件对浮力材料模型试验过程进行仿真,分析不同钢筒壁厚对试验的影响规律。[结果]研究结果表明,该试验测试方法可被用于准确测量低模高弹体材料的泊松比值,适用于低模量、高弹特性材料的力学性能研究。[结论]研究工作可为相关试验测试提供参考。

Abstract:[Objectives]There are many problems in the axial load of low modulus and high elasticity samples,such as large deformation and poor uniformity,and it is difficult to accurately measure the Poisson's ratio of such material using the conventional resistance strain test method.[Methods]In this paper,based on the theory of elastic mechanics,the expressions of the volume compression modulus,elastic modulus and Poisson's ratio of a cylindrical low modulus elastomer with radial rigidity constraint are derived.On the basis of the above theoretical analysis,this paper puts forward a test method for the axial loading Poisson's ratio of a steel sleeve radial constraint,and carries out related experimental research work on steel tube restraint to determine the accuracy and effectiveness of the final verification test method.Finally,a simulation analysis of the buoyancy material model test process is carried out,and the wall thicknesses of different steel sleeves are simulated to illustrate the influence of wall thickness on the test.[Results]Research into the low modulus elastomer Poisson's ratio test method can obtain the accurate measurement of the Poisson's ratio of the material,making it suitable for studying the mechanical properties of the low modulus and elasticity modulus of the elasticity of material.[Conclusions]The research results of this paper can provide valuable references for related testing.