| 扁长杆的冲击弹塑性屈曲特性分析的仿真有限元模型 |
| 刘赛, 吕振华 |
| 清华大学 汽车工程系, 北京 100084 |
| Finite element model refinement for elastic-plastic dynamic buckling of a belt bar during impact |
| LIU Sai, LÜ Zhenhua |
| Department of Automotive Engineering, Tsinghua University, Beijing 100084, China |
摘要:
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| 摘要已有文献进行了微弓形扁长金属杆在轴向重物冲击下的动态屈曲实验研究，得到了扁长杆冲击屈曲响应的典型结果，但已有文献及后来相关论文的模拟计算精度较低。为了提高典型扁长杆的冲击屈曲特性的计算分析精度，该文研究了扁长杆的冲击屈曲特性分析的有限元建模方法，改进了有限元模型边界条件的建模仿真度（考虑了转动铰配合间隙、摩擦等），并探讨了有限单元型式及尺度的选择，以壳单元或实体单元模型代替梁单元模型。研究表明：采用改进边界条件（考虑转动铰配合间隙、摩擦等）和薄壳单元或厚壳单元或实体单元的仿真模型比采用理想边界条件和梁单元的原模型的计算结果精度显著提高；基于改进模型的计算分析结果，揭示了该扁长杆受冲击载荷作用时的3维动态反向屈曲行为。 | |||
| 关键词 ：动态屈曲,扁长杆,轴向冲击,有限元分析,模型修正,3维反向屈曲 | |||
| Abstract：The dynamic buckling experiment of a belt bar subjected to axial impact was previously studied experimentally. The tests show that previous simulation methods are not very accurate. The finite element analysis accuracy is improved by improving the fidelity of the boundary conditions and properly selecting the finite element type and size. The boundary conditions for the joint clearance and friction are determined by comparing the numerical results with the test data, and shell elements and solid elements are found to give better results than beam elements. Simulations with thin or thick shell elements or solid elements with the new boundary conditions are more accurate than previous results with beam elements and simple boundary conditions. The refined finite element model predicts the 3-D reverse buckling of the belt bar. | |||
| Key words：dynamic bucklingbelt baraxial impactfinite element analysismodel refinement3-D reverse buckling | |||
| 收稿日期: 2016-01-24 出版日期: 2016-10-25 | |||
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| 通讯作者:吕振华,教授,E-mail:lvzh@tsinghua.edu.cnE-mail: lvzh@tsinghua.edu.cn | |||
| 引用本文: |
| 刘赛, 吕振华. 扁长杆的冲击弹塑性屈曲特性分析的仿真有限元模型[J]. 清华大学学报（自然科学版）, 2016, 56(10): 1104-1108. LIU Sai, LÜ Zhenhua. Finite element model refinement for elastic-plastic dynamic buckling of a belt bar during impact. Journal of Tsinghua University(Science and Technology), 2016, 56(10): 1104-1108. |
| 链接本文: |
| http://jst.tsinghuajournals.com/CN/10.16511/j.cnki.qhdxxb.2016.22.046或 http://jst.tsinghuajournals.com/CN/Y2016/V56/I10/1104 |
图表:
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| 图１ 受重物冲击的微弓形扁长杆[1,8] |
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| 表１ 扁长杆的微弓形弧函数[1] |
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| 图２ 基于梁单元模型和理想边界条件的计算分析结果 |
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| 图３ 扁长杆端部的结构和特征尺寸 |
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| 图４ 扁长杆端部的有限元网格 |
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| 表２ 薄壳单元模型的改进边界条件参数 |
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| 图５ 基于薄壳单元模型和改进边界条件的计算分析结果 |
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| 表３ 单元尺度的优选范围和优选结果 |
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| 图６ 基于改进边界条件的多种单元模型的计算分析结果 |
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| 图７ 薄壳单元模型在t＝0.75ms时刻的屈曲变形曲线和等效应力云图(3个断面图中的横向屈曲变形放大50倍) |
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