超参壳元的TUL显式计算格式

TUL deformation formulation for explicit dynamic analysis based supper-parametric shell elements

针对含有大变形和材料非线性的壳的有限元显式动力分析 ,提出了一种结合 TL (total L agrange)和 UL(updated L agrange)计算格式的 TU L格式。在新的计算格式中 ,应力只参考于若干 (n)个时间步 (增量 )前的构形来度量。在求解基于超参壳元的问题时 ,使用 TU L 格式克服了 UL格式计算时间长和 TL格式小转动的限制。数值算例表明 ,选择合适的参数 n,在达到相近的计算精度的前提下 ,TUL格式的计算效率成倍增加。在求解如汽车碰撞等大规模冲击接触问题时 。

By combining the TL (total Lagrange) and UL (updated Lagrange) formulations, a TUL deformation formulating for the explicit dynamic analysis of large deflection and materially nonlinear response of dynamic loaded shells is presented. In the new formulation, the configuration at time ( t-n· Δ t ), neither the initial configuration at time 0 nor the latest known configuration at time ( t- Δ t ), is adopted as the referred configuration to determine the stresses. The TUL approach can not only overcome the disadvantage of longer computation time in the UL formulation, but also exist no limitation of small rotation in the TL formulation for the problems employing the super parametric shell elements. Numerical results show that the method with TUL formulation is comparable in accuracy with the algorithm employing UL formulation, even substantially faster if the appropriate parameter n is given. This feature is very important for the large scale contact impact problems, such as vehicle crashworthiness analyses.