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摘要: 基于连续介质理论, 通过建立车辆碰撞的控制方程, 在此基础上得到与控制方程和边界条件等效的“弱积分”形式。通过空间和时间的显式离散, 得到了车辆碰撞的有限元方程。采用动力显式积分方法, 使位移计算显式化, 避免了由材料、几何、边界高度非线性因素引起的计算收敛问题, 并讨论了薄板单元的Courant稳定性条件。提出了“端部吸能结构纵向压缩变形、纵向吸能”的耐冲击结构设计的思路, 并对算例进行了数值模拟。结果表明, 该设计方法可以实现车辆结构自身被动安全保护的目的, 显式有限元数值模拟方法是车辆耐撞性研究的有效方法之一, 但是需要进行部分撞击试验, 进一步修正模型后提高其分析精度Abstract: Based on the continuum mechanics, governing equations of vehicle collisions were set up and the weak form of the equilibrium equations was found. Through explicit discretization of space and time, finite element equation was obtained. By utilizing dynamic explicit integral, nodal displacements were calculated explicitly, which avoids the convergence problem caused by highly non-linear factors including material, geometry, boundary. Also the Courant stability condition for thin-shell element was discussed. The design method of crashworthy structure longitudinal compress deformation, longitudinally absorbing energy was proposed and numeric simulation on an example was carried out. The results show that the design method can realize self-structure passive safety and the explicit finite element method is an effective way for structure crashworthiness research. But it is necessary to carry out some crash tests so as to modify the numeric model and!improve simulation accuracy.
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Key words:
- explicit finite element method /
- vehicle /
- crashworthiness /
- non-linear
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[1] 王勖成, 邵敏. 有限单元法基本原理和数值方法[M]. 北京: 清华大学出版社, 1998. [2] 钟志华, 李光耀. 薄板冲压成型过程的计算机仿真与应用[M]. 北京: 北京理工大学出版社, 1998. [3] 匡震邦. 非线性连续介质力学基础[M]. 西安: 西安交通大学出版社, 1989. [4] 宋天霞. 非线性结构有限元计算[M]. 武汉: 华中理工大学出版社, 1996. [5] 谢贻权, 何福保. 弹性和塑性力学中的有限元法[M]. 北京: 机械工业出版社, 1986. [6] 田红旗. 客运列车耐冲击吸能车体设计方法[J]. 交通运输工程学报, 2001, 1(1): 110-114. http://transport.chd.edu.cn/article/id/200101028TIAN Hong-qi. Grashworthy energy absorbing car-body design method for passenger train[J]. Journal of Traffic and Transportation Engineering, 2001, 1 (1): 110-114. (in Chinese) http://transport.chd.edu.cn/article/id/200101028 [7] 王仁. 塑性力学基础[M]. 北京: 科学出版社, 1998. [8] 余同希, 华云龙. 结构塑性动力学引论[M]. 合肥: 中国科技大学出版社, 1994.