| Summary: | 碩士 === 中原大學 === 土木工程研究所 === 92 === In this paper, the vector form intrinsic finite element (VFIFE) method with displacement control is applied to simulate the geometrically nonlinear behaviors of space truss structures. Different from the conventional finite element method which is based on the variational theory, the VFIFE method is a physical model which models the analyzed domain to be composed by finite particles and Newton’s second law is applied to describe each particle’s motion. Thus, the calculation of VFIFE method becomes solving a set of uncoupled vector form equations. In the analysis of VFIFE method, the co-rotational coordinate system is used to separate the rigid body motion and pure deformation of the system. After combining it with explicit time integration scheme, the VFIFE method can effectively simulate the dynamic behaviors of multi-bodies system having large rigid body motion and deformation.
The forces of original VFIFE method are known and the motions of body are the results of the forces, but many problems like mechanism and automatic control device, the motion of body is prescribed, the applied forces are unknown, hence the behaviors of many structures can not simulate with force control only. In this study, the VFIFE method with displacement control is applied on the space structures to demonstrate feasibility of this strategy.
The governing equations of motion of original VFIFE method is dynamic equilibrium of force, in this study, VFIFE method with dynamic equilibrium of momentum is applied on the space structures. The time integration schemes in dynamic equilibrium of force and momentum are the same, and the advantages of dynamic equilibrium of momentum are: (1) a better capability in capturing the rapid changes of dynamic loading and (2) a less error propagation effect. The procedures and results of VFIFE method with dynamic equilibrium of force and momentum are discussed and compared on space structures.
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