中密度纤维板弹性常数及其阻尼比的动态测试

摘要

以中密度纤维板(MDF)为研究对象, 应用梁和板振动理论, 探索了自由和悬臂两种约束状态下, MDF的弹性模量和剪切模量动态测试值随试件长宽比的变化规律;根据随机信号与振动分析系统(CRAS)对各向同性材料悬臂板的模态应力、 应变分析, 由σy=0确定了动态测试MDF泊松比的应变花粘贴位置, 且动态测试了MDF泊松比;为保证MDF动态测试泊松比的可行性, 还试验分析了由σy=0确定的应变片粘贴位置的允许变化范围;最后用方板扭转试验测试了MDF的静剪切模量, 以验证动态测试剪切模量方法的适用性.对MDF材料类别属性进行了分析, 试验验证了MDF可视为准各向同性材料.%In this paper, MDF specimens with homogeneous material was studied according to the dynamic testing theory, to explore the free and cantilever constraint conditions, and analysis of value with the ratio of length to width variation of MDF elastic modulus and shear modulus were compared.According to the modal strain and strain analysis of the cantilever plate of the isotropic material, ANSYS is used to determine the position of the strain gauge in the dynamic test MDF Poisson′s ratio by σy=0, and the MDF Poisson′s ratio was measured dynamically.In order to ensure the feasibility of dynamic testing of the Poisson′s ratio of MDF, the allowable variation range of the position of the strain gauge by σy=0 was also tested.Finally, the static shear modulus of MDF was measured by the square plate torsion test to verify the applicability of the dynamic shear modulus method.The categorical attribute of MDF material was analyzed, and the MDF was regarded as quasi-isotropic material.