Abstract

Thin-plate structures are widely exploited in many areas due to their excellent structural properties. This study numerically investigates the mechanics characteristics of the stress mode shapes (SMSs) in thin plates. First, theoretical basis of the SMSs is concisely illustrated for thin-plate structures. Then, finite element models are constructed in numerical simulations. The SMSs of the flat plate are compared with the conventional displacement mode shapes (DMSs). The modal participation factors (MPFs) are used to extract the predominant SMSs. The SMSs in x-, y-, xy- directions and von Mises stress are evaluated in detail. Based on results of the flat plate, local thickness and elastic modulus modifications are performed to examine the changes in SMSs. Modal assurance criterion (MAC) is utilized to evaluate the modal data. The information of SMSs from the modified plates indicates the powerful capability for detecting the local variations of structural properties. Lastly, modal order determination via modal effective mass is numerically verified for accurate dynamic stress calculation.

摘要

薄板结构因其优异的结构性能在许多领域得到广泛应用。本研究以数值方式研究了薄板中应力振型 (SMS) 的力学特性。首先，针对薄板结构简要说明了 SMS 的理论基础。然后，在数值模拟中构建有限元模型。将平板的 SMS 与传统的位移模态振型 (DMS) 进行了比较。模态参与因子 (MPF) 用于提取主要的 SMS。x -, y -, xy中的 SMS- 详细评估方向和 von Mises 应力。根据平板的结果，执行局部厚度和弹性模量修改以检查 SMS 的变化。模态置信度 (MAC) 用于评估模态数据。来自改性板的 SMS 信息表明检测结构特性局部变化的强大能力。最后，通过模态有效质量确定模态阶数，对精确的动态应力计算进行了数值验证。