船底座礁实验数值模拟中选择参数影响研究

非线性有限元方法是分析船舶碰撞和搁浅问题的一个强有力工具,但是数值模拟结果的可靠性很大程度上依赖于对工程问题的恰当处理和有限元软件中主要参数的准确控制.本文以某单壳船底结构准静态座礁实验结果为例,用非线性有限元软件LS-DYNA进行数值模拟,研究了下列选择参数对单壳船底结构抗撞性的影响:边界条件;船底结构的材料模型;壳单元类型;船底结构与礁石模型之间的摩擦系数;船底结构的残余应力.通过比较计算结果的碰撞力曲线,能量吸收曲线来评价这些参数对数值模拟的影响并给出了一些建议.

Study on the effect of selected parameters for numerical simulation of bottom grounding experiment

Nonlinear finite element method(FEM) is a powerful tool for analyzing ship collision and grounding problems.The reliability of the numerical simulation results largely depends on the proper definition of problem and careful control of some critical parameters.The purpose of the paper is to study the effect of selected design parameters on crashworthiness of the single-hull bottom structure due to raking.The quasi-static grounding process is simulated by the LS-DYNA code.The effects of the following parameters are considered: the boundary condition,the friction coefficient,shell element type,the residual stress and the material model.The influences of selected parameters are assessed by comparing the different results in the impact force and absorbed energy vs.penetration of rock model.Some suggestions are proposed for numerical simulation in finite element code LS-DYNA.