三维离散元与壳体有限元耦合的时空多尺度方法

A MULTISCALE METHOD OF TIME AND SPACE BY COUPLING THREE-DIMENSIONAL DEM AND CYLINDRICAL SHELL FEM

壳体结构的局部失效及其对整体结构稳定性影响涉及到跨宏细观多尺度力学问题。该文推导出元/网格动量传递的多尺度算法,建立了三维离散元与壳体有限元耦合的时空多尺度数值计算方法。通过激光辐照下充内压圆柱壳局部失效算例的数值模拟,验证该多尺度方法能够完善地并行实现时间多尺度与空间多尺度计算,不仅能够准确模拟壳体结构局部细观非均匀演化及其对整体结构的影响,而且计算时间很少,有效地发挥了时空多尺度模拟高效率优势。

The Failure of a partial cylindrical shell structure and its effects on the stability of the macroscopic structure involve the multiscale mechanical problems in bridging macroscopic and mesoscopic scales. The multiscale algorithm of element/mesh momentum transfer was deduced, and the multiscale numerical method of time and space by coupling three-dimensional DEM （Discrete Element Method） and cylindrical shell FEM （Finite Element Method） was established. Validated by the simulations in the partial failure of the cylindrical shell subjected to inner pressure and surface laser irradiation, this multiscale method could perfectly accomplish multiscale time and multiscale space computations synchronously, which not only simulated the mesoscopic heterogeneous evolvements of the partial cylindrical shell and their effects on the whole cylindrical shell accurately, but also consumed a little computation time and exerted the advantage of high efficiency of multiscale simulation effectively.