長さ変化を伴う柔軟体の非線形動力学解析

抄録

In recent years, flexible multibody dynamics has been used to solve this problem. When solving this spaghetti problem by finite element method, some elements move across the boundaries between the constrained area and non-constrained area,so it is necessary to distinguish which nodes is in the constrained area, it makes the analysis more complicated. Using the ALE (Arbitrary Lagrangian-Eulerian) finite element method, some nodes can be fixed at boundaries and other nodes can be arranged arbitrarily in each area. This will make it easier to analyze the flexible body with time-varying length which occurs the spaghetti problem. This study developed a method for analyzing flexible bodies with time-varying length by combining the ALE finite element method and the ANCF (Absolute Nodal Coordinate Formulation), which is one of the formulation of flexible multibody dynamics. In this model, the element coordinates of each nodes are used as the generalized coordinates, and by changing these coordinates with time, it is possible to express the arrangement of the nodes like ALE finite element method and the time varying length of the flexible body. In order to verify the validity of the analysis using this model, this study analyze the flexible body with time-varying length, and compares the result with previous study. As a result, it was shown that the analysis could be performed with the time step larger than in previous The increase in the vibration that occurs when material length varying with time is known as the spaghetti problem.