【作者】 黄俊；

【导师】 袁建华；

【作者基本信息】 华中科技大学 ， 机械电子工程， 2008， 硕士

【摘要】 方舱作为一种移动箱式工作间是常应用于军用汽车上的特殊车厢。在热载荷作用下的脱层问题是方舱使用过程中出现最多的质量问题,对方舱的性能及外观造成极大的危害。本文以解放军某工厂某型号通信指挥方舱为研究对象,应用有限元方法对该方舱在热载荷作用下的脱层质量问题进行了研究。分析了热载荷状况下方舱的传热形式,建立了方舱温度场计算的传热模型。根据工厂提供的方舱结构及外形尺寸,应用三维建模软件进行了几何建模。通过对方舱舱体有限元模型建模方案的比较和研究,提出了一种适合大板式方舱及类似结构分析的有限元建模方案。根据方舱实际工作热载荷工况,运用有限元软件分析得到了方舱舱体温度场分布。通过热—结构耦合的方法,运用有限元软件对方舱舱体热变形及组成方舱的各部件热应力进行了分析。通过对计算结果的分析,得到热载荷下方舱大板芯材表层材料受压失效是引起舱体脱层的一个原因。在舱体热应力分析结果的基础上,对芯材含近表层空洞缺陷的方舱大板热应力作了分析,讨论了空洞大小对芯材应力状况的影响,得到芯材中存在的较大空洞是引起脱层的又一重要原因。分析结果与工厂实验结果有较好的一致性,证明了分析的正确性。为解决脱层问题,应增强芯材表层强度和控制空洞尺寸。以有限元分析所得的结论为依据,结合方舱舱体生产工艺,提出了解决方舱脱层质量问题的一些可行性措施。更多还原

【Abstract】 As box-type mobile workstations, shelters are frequently used as special carriages of military vehicles. The delaminating problem under thermal loads, which does great harm to the function and appearance of shelters, is the most common quality problem during the lifecycle of shelters. In this thesis, one type of communication command shelter in one of PLA’s factory has been studied, and FEM (finite element method) was introduced to research the delaminating problem under thermal loads.This thesis first analyzes the forms of heat transfer under thermal loads, and establishes a heat transfer model for the temperature field calculation. CAD software is applied to establish the geometric model according to the drawings that the factory provided. By comparison and research of several finite element models, a finite element model is established for the shelter body and other similar structures. And the temperature field of the shelter under real thermal environment is got with FEM software.The thermal-structural coupled method with FEM software is used to get the thermal deformation of the shelter and the thermal stress of the components of it. The analysis on the results shows that the damage caused by the thermal stress in the upper layer of the core material of the board is an important cause of delamination. Based on the thermal stress analysis of the whole shelter, the core material with void defects of various sizes in the upper layer is analyzed, which shows that the void defect is another important factor causing delamination. The consistency between the analysis and the experimental results of the factory proved the correctness of the analysis in this thesis. To solve the delaminating problem, the core material strength should be enhanced and the surface void size should be controlled.Finally, combined with the production process of the shelter body, some feasible measures are proposed to solve the delaminating problem on the basis of the FEM analysis results.更多还原