笔记本电脑的跌落仿真研究

发布时间：2018-01-21 18:38

本文关键词： 笔记本电脑模态分析跌落仿真跌落实验优化设计　出处：《东南大学》2016年硕士论文　论文类型：学位论文

【摘要】：笔记本电脑在日常工作学习使用时,不可避免的会发生意外跌落现象,而造成严重的结构或功能损坏,因此企业在笔记本电脑出厂前都需要进行物理样机的跌落测试,以验证其跌落性能是否满足行业标准。传统的物理跌落实验作用时间短且不易控制,为了降低成本,缩短产品生产周期,提高笔记本电脑抗冲击性能,本文依托CAE技术,对笔记本电脑整机进行模态分析、跌落性能分析及优化设计。以下是本论文的主要工作及成果：(1)利用Hypermesh软件简化笔记本电脑三维模型,首次提出了一套通用完整的笔记本电脑有限元模型建立方法,将整机模态仿真及自由模态实验的结果对比,固有频率最大误差为7.6%,模态振型基本一致,从而验证了建立的有限元模型的准确性。(2)基于碰撞理论,对笔记本电脑从50cm高度,选取棱跌落、角跌落、面跌落三种典型跌落姿态进行跌落仿真,得到了跌落过程中整机各零部件间力的传递情况,及每一个输出时间节点下的加速度、应力、应变、变形云图,并得出主要结论：1.角跌落为最危险跌落工况；2.顶盖部分刚度较机座较低,对LCD保护效果差,应在优化中重点提高顶盖部分刚度。(3)分析产品脆值,提出通过加速度验证跌落仿真结果的方法。将笔记本电脑样机在棱跌落、角跌落、面跌落三种跌落工况下得到的加速度时间历程曲线,与仿真所得加速度曲线进行对比,曲线形态基本一致,最大加速度值误差在可接受范围内,验证了跌落仿真的有效性,说明跌落仿真结果可以作为产品优化的基础。(4)基于模态分析,跌落仿真,跌落实验结果得到结论：顶盖外壳刚度低,对顶盖内部零件保护效果差。以笔记本电脑顶盖为对象,提出以下三种优化方案：1.顶盖外壳材料优化设计；2.后盖板凹槽设计；3.后盖角部筋板拓扑优化设计。整合对比三种方案,得到最佳顶盖优化模型。结果表明：在改动质量变化不大的情况下,优化后的模型在角跌落、棱跌落、面跌落三种工况下,顶盖部分所有零件(后盖、前框、LCD支架、LCD金属边框及LCD)上的应力均明显减小,优化效果明显。
[Abstract]:When the notebook computer is used in daily work and study, it is inevitable that the phenomenon of accidental fall will occur, resulting in serious structural or functional damage. Therefore, enterprises need to test the drop of the physical prototype before the notebook computer leaves the factory to verify whether the drop performance meets the industry standard. The traditional physical drop test has a short time and is not easy to control. In order to reduce the cost, shorten the production cycle and improve the impact resistance of notebook computer, this paper carries out modal analysis of the whole laptop computer based on CAE technology. Drop performance analysis and optimization design. The following is the main work and achievement of this paper: 1) using Hypermesh software to simplify the 3D model of notebook computer. A set of universal and complete finite element modeling method for notebook computer is proposed for the first time. The results of modal simulation and free mode experiment show that the maximum error of natural frequency is 7.6 and the modal shape is basically the same. Therefore, the accuracy of the established finite element model is verified. (2) based on the collision theory, three typical drop postures of notebook computer from 50cm height, angle drop, angle drop and surface drop are simulated. The transmission of the force between the parts of the whole machine and the acceleration, stress, strain and deformation of each output time node are obtained. The main conclusions are as follows: 1. Angle drop is the most dangerous drop condition. 2. The stiffness of the roof part is lower than that of the base, and the effect of LCD protection is not good. Therefore, emphasis should be placed on improving the stiffness of the top cover part. 3) to analyze the brittleness value of the product. The acceleration time history curve of the notebook computer prototype is obtained under three conditions: angle drop, angle drop and surface drop. Compared with the simulated acceleration curve, the shape of the curve is basically the same, and the error of the maximum acceleration value is within the acceptable range, which verifies the effectiveness of the drop simulation. The results show that the drop simulation results can be used as the basis of product optimization. (4) based on modal analysis, drop simulation, drop experiment results show that the shell stiffness of the top cover is low. The protection effect of the interior part of the top cover is poor. Taking the top cover of the notebook computer as the object, the following three optimization schemes are put forward: 1. The optimum design of the shell material of the top cover; 2. The design of the recess of the back cover plate; 3. Topology optimization design of the corner stiffened plate of the rear cover. The optimal roof optimization model is obtained by integrating three schemes. The results show that the optimized model falls in the angle and the edge falls when the quality of the change is not changed much. The stress on all parts of the top cover (back cover, front frame LCD bracket, LCD metal border and LCD) is obviously reduced under three conditions of surface drop, and the optimization effect is obvious.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP368.32

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