船体结构的水弹塑性方法研究

Collapse of ship structure is a nonlinear dynamic phenomenon when ship structure is encountering to extreme wave, it is necessary to consider the interaction of ship structural nonlinearity and extreme wave. This study is to improve a previous 2D hydroelasto-plasticity proposed by applicant. Hydroelasto-plasticity involves the coupling between strong structural nonlinearity and wave nonlinearity, this numerical hydroelasto-plasticity method proposed in this study doesn’t consider wave nonlinearities such as viscosity of wave and breaking wave, the coupling between structural nonlinearity and wave based on potential theory is considered, nonlinearity of ship rigidity is considered, elastic and plastic modal shapes are superposed so that the ship deformation calculated by the hydroelasto-plasticity method is closer to plastic deformation. In addition, a hydroelasto-plastic model is designed to carry out a hydroelasto-plastic test which has not been performed in our country to fill the research vacancy. The two means involving numerical hydroelasto-plastic method and hydroelasto-plastic test are used to study the nonlinear dynamic strength of ship structure in extreme waves, the numerical method is used to design and conduct hydroelasto-plastic test, and the hydroelasto-plastic test is used to verify and improve the numerical hydroelasto-plastic test.

船体结构与极端波等大波高波浪遭遇时，导致的船体结构崩溃是一种动非线性的动态过程，其与大波浪之间的作用是非常有必要被考虑的。本研究拟基于申请人前期提出的一个二维水弹塑性数值方法的基础上，进一步改进该二维水弹塑性数值方法。水弹塑性涉及到极强的结构非线性与波浪非线性之间的耦合问题，此二维水弹塑性数值方法暂不考虑波浪的粘性及破波等波浪非线性，基于势流理论考虑结构的非线性与波浪之间的耦合，主要考虑船体梁刚度的非线性，拟采用弹性模态与塑性模态的共同叠加，使船体梁的水弹性数值塑性变形更接近真实情况。另外再设计一种水弹塑性船模，开展船模在水池中的水弹塑性试验，填补国内在船体水弹塑性模型设计和水弹塑性试验方面的研究空缺。采用水弹塑性数值方法与水弹塑性试验两个手段来研究船体在复杂海况下的非线性动态强度，用数值方法来设计指导试验，用水弹塑性试验来验证和完善水弹塑性数值方法。

本课题拟提出水弹塑性方法来研究船体结构在极端波下的非线性动态强度和变形，此水弹塑性方法的研究内容包括理论数值方法研究和水弹塑性试验两部份。本项目的研究目标为设计并开展一个船体模型的水弹塑性试验方法，通过该水弹塑性试验结果，提出并进一步完善水弹塑性理论和方法。本项目成功设计了一个水弹塑性模型，该水弹塑性模型由两个刚体船体和一个船中塑性铰组成，该塑性铰即使在水池波浪中也能产生崩溃响应，并且也开展了水弹塑性模型试验，成功地开展了水弹塑性模型在单波和规则波下的水弹塑性试验。本项目结合非线性有限元与势流理论，发展水弹塑性数值方法。通过仿真结果与试验结果进行对比，相互修正，得到较佳的结果。申请者借助国家自然科学基金平台在项目执行期间前后共发表共发表1篇SCI论文、2篇中文核心EI期刊论文、多篇重要国际会议论文及申请发明专利1项。