Contact and Impact Dynamic Modeling Capabilities of LS-DYNA for Fluid- Structure Interaction Problems

摘要

Fluid-structure interaction (FSI) is a very interesting and challenging multi-disciplinary field involving interaction of a movable or deformable structure with an internal or surrounding fluid flow. FSI plays a pivotal role in many different types of real-world situations and practical engineering applications involving large structural deformation and material or geometric nonlinearities. Modeling the ocean environment (deep and shallow water, and surf and beach zones), and loads and motions of platforms and deployed systems accurately or studying the dynamic response of a rigid object as it impacts the water surface are some of the applications of FSI addressed in this research. This dissertation is aimed at evaluating the predictive capability of an advanced multi-numerical solution techniques approach to evaluate the contact and impact dynamic modeling capabilities of a finite element code LS-DYNA for Fluid-Structure-Interaction (FSI) problems. To this end, the nonlinear dynamic behavior of water impact of a rigid object is modeled using different numerical methods. The simulations thus far utilize an Arbitrary Lagrangian and Eulerian (ALE) technique and discrete particle model such as the Smoothed Particle Hydrodynamics (SPH) method to capture the multi- physics phenomenon. The dynamics of a water-landing object (WLO) during impact upon water is also presented in this dissertation. Experimental tests for a range of drop heights were performed in a wave basin using a 1/6th scale model of a practical prototype to determine the water impact effects and the results were compared with analytical and numerical predictions. The predictive capability of ALE and SPH features of LS-DYNA for simulation of coupled dynamic FSI responses of the splashdown event of a WLO were evaluated.