摘要
用膜单元和索单元模拟降落伞织物绳索系统,基于完全拉格朗日格式的非线性有限元方法编程计算降落伞的结构动力学特性。采用增量与迭代混合方法改善非线性计算的收敛特性并结合HHT隐式时间推进方法减小整体迭代计算量。使用修正应力应变张量导数的方法模拟膜单元单向应力状态并针对膜单元和索单元分别进行了非线性有限元计算验证。最后针对C-9型降落伞建立三维有限元模型,根据设定流速对伞衣施加均匀压强载荷,将模拟展开的结果与使用相同模型、不同方法商业软件的文献进行对比,显示了隐式非线性有限元方法模拟降落伞膜索系统大变形动力学的能力。
A membrane-cable tension structure is presented in this paper to represent the three dimen-sional parachute system and simulate the parachute opening process.The combined incremental/iterative method based on the total Lagrangian scheme is adopted here to develop a nonlinear finite element analy-sis code.The fully implicit HHT method is applied to integrate nonlinear dynamic equations and improve the convergence speed.Membrane wrinkling phenomena are also accounted for by modifying the geomet-rical deformation tensor.The nonlinear finite element algorithms for membrane and cable are tested re-spectively and compared with former literature.Finally,the opening dynamic behavior of a C-9 parachute structural model is simulated by prescribing the constant pressure loading according to the air speed.The final results show agreement with the solutions provided by commercial software in former literature which used different methods.This example demonstrates the ability of this to simulate parachute large deformation problem.
出处
《计算力学学报》
CAS
CSCD
北大核心
2014年第6期793-798,共6页
Chinese Journal of Computational Mechanics
关键词
膜单元
索单元
非线性有限元
褶皱
降落伞
membrane element cable element nonlinear finite element wrinkling parachute
