애벌레 소프트 액추에이터 해석을 위한 무요소 유체 구조 연성 기법 개발

Abstract

The purpose of this study was to develop a meshless fluid-structure interaction (FSI) method based on meshless local Petrov-Galerkin (MLPG) method for both the fluid and the structure to analyze the bending behavior of a larva soft actuator. Previous research has used finite element methods (FEM) to simulate the behavior of soft actuators. However, the nonlinear behavior of a soft actuator causes mesh distortion and discontinuous stress between the adjacent meshes, even when adaptive mesh is applied in the FEA. To analyze with the nonlinearity of a soft actuator, MLPG was applied in the simulation to exactly analyze the nonlinear behavior of a soft actuator without using finite elements. In addition, a pneumatic larva soft actuator simulation requires two-way FSI analysis that can transmit and receive data between the structure and the fluid, and the fluid and the structure, in sequence. Additionally, the arbitrary Lagrangian Eulerian (ALE) method and level set method (LSM) were applied to increase accuracy for the mesh boundary. A comparison of the results between the simulations and the experiment verified that the proposed FSI method yields a maximum error of 0.77%, which is lower than the 4.69% for FEM, and that it needs fewer nodes for simulation than FEM.