P/G类建筑织物膜材双轴剪切试验及力学特性分析

Biaxial Shear Test and Mechanical Property Analysis of P/G Type Architectural Fabrics

关键词:  剪切模量  双轴剪切试验  建筑织物膜材  剪应力剪应变曲线

Key words:  shear modulus  biaxial shear test  architectural fabric  shear stress stain curve

摘要:

为测试建筑织物膜材的力学特性，对4种建筑织物膜材进行了双轴剪切试验，得到其剪应力剪应变曲线、残余剪应变、滞回环面积和剪切模量.分析结果表明：每个应力阶段的第1次循环G类膜材均会产生明显的塑性剪切变形，P类膜材以弹性变形为主；随着循环次数的增加，建筑织物膜材的剪应力剪应变曲线的加载上升段线性特征增强，加载段斜率逐渐增大；剪应力由正变负后，建筑织物膜材的残余剪应变、滞回环面积和加载段斜率有所差异；考虑加载全周期计算得到的剪切模量比仅考虑各应力阶段的最后1个周期计算得到的剪切模量小；4种建筑织物膜材剪切模量为FGT 800>FGT 600>F 1202> F 1002.

Abstract:

In order to measure the mechanical property of architectural fabrics, a test method of biaxial shear test was used. The biaxial shear tests for four kinds of architectural fabrics were carried out, then the shear stress strain curves, shear modulus, residual shear strains and hysteresis loop area were obtained. The analysis results show that the plastic shear deformation of G type fabric is notable, but the shear deformation of P type fabric is mainly elastic at the first cycle of each stress stage. The linear feature of the load rising segment of shear stress strain curves enhances and loading slope increases gradually with the increase of the number of cycles. The residual shear strains, hysteresis loop area and loading slope are different when the direction of shear stress is changed. The shear modulus calculated by considering the all cycles are smaller than those calculated only considering the last cycle of each stress stage. The sequence of shear modulus of fabrics is FGT 800>FGT 600>F 1202>F 1002.