Modeling of Welded Joints in a Pyramidal Truss Sandwich Panel Using Beam and Shell Finite Elements
Modeling of Welded Joints in a Pyramidal Truss Sandwich Panel Using Beam and Shell Finite Elements
复制标题
DOI：
10.1115/1.4048792
复制
发表时间：
2021-08
期刊：
影响因子：
--
通讯作者：
K. Yuan;Wei-dong Zhu
中科院分区：
文献类型：
--
作者：
K. Yuan;Wei-dong Zhu
四角锥桁架夹芯板在工程结构中应用广泛，其面板与芯部通常采用焊接工艺连接。为了获得精确的模态参数，在对带焊接接头的PTSP进行有限元分析时，通常需要使用大量的实体单元。忽略PTSP的焊接接头可以节省许多自由度（DOF），但会显著改变其固有频率。本文的研究目的是精确地确定具有比实体单元模型少得多的自由度的焊接接头的PTSP的模态参数，并通过避免遗漏其模态来获得其工作模态分析结果。提出了两种将焊接节点视为等效刚度的新方法来建立PTSP的梁壳单元模型。其主要步骤是将焊接接头的梁单元和壳单元的刚度与实体单元的刚度进行匹配。与PTSP的实体单元模型相比，其建议的模型提供了几乎相同的精度水平的固有频率和模态振型的前20个弹性模式，而减少自由度约98%的整个结构和99%的每个焊接接头。前14个弹性模式的PTSP标本，测量没有错过任何模式，通过同步捕获其双面振动，通过使用三维扫描激光测振仪（SLV）和反射镜实验验证其梁-壳单元模型所提出的两种方法。
Pyramidal truss sandwich panels (PTSPs) are widely used in engineering structures and their face sheets and core parts are generally bonded by the welding process. A large number of solid elements are usually required in the finite element (FE) model of a PTSP with welded joints to obtain its accurate modal parameters. Ignoring welded joints of the PTSP can save many degrees of freedom (DOFs), but significantly change its natural frequencies. This study aims to accurately determine modal parameters of a PTSP with welded joints with much fewer DOFs than those of its solid element model and to obtain its operational modal analysis results by avoiding missing its modes. Two novel methods that consider welded joints as equivalent stiffness are proposed to create beam-shell element models of the PTSP. The main step is to match stiffnesses of beam and shell elements of a welded joint with those of its solid elements. Compared with the solid element model of the PTSP, its proposed models provide almost the same levels of accuracy for natural frequencies and mode shapes for the first 20 elastic modes, while reducing DOFs by about 98% for the whole structure and 99% for each welded joint. The first 14 elastic modes of a PTSP specimen that were measured without missing any modes by synchronously capturing its two-faced vibrations through use of a three-dimensional scanning laser vibrometer (SLV) and a mirror experimentally validate its beam-shell element models created by the two proposed methods.