基于离散模块梁单元水弹性理论的复杂连接处建模方法

Modelling methods for complex interconnection of very large floating structures based on discrete-module-beam hydroelasticity theory

[目的]在离散模块-梁单元(DMB)水弹性理论框架下,提出针对连接形式复杂的超大型浮体结构(VLFS)的新的建模方法,并与已有方法进行对比分析。[方法]首先,概述基于DMB的水弹性分析方法,给出求解连续VLFS结构在波浪作用下的动力响应步骤;然后,针对VLFS复杂连接处进行建模,通过定义连接处的刚度矩阵,对与连接处相邻的两个集中质量间的力与位移关系进行修正,获得新的结构刚度矩阵和受力矩阵,并求解水弹性方程;最后,探究在弯曲刚度变化时采用4种方法求得的VLFS结构动力响应的变化趋势,分析各方法存在差异的原因。[结果]结果表明,4种建模方法都可以准确地计算出连接形式复杂的VLFS结构水弹性响应。[结论]所述建模方法可以用于计算多铰接或具有断裂位置的非连续VLFS结构的动力响应,并可拓展DMB方法的应用范围。

[Objective]The aim of this paper is to proposes new methods for modelling a very large floating structure(VLFS)with complex connections in the framework of the discrete-module-beam(DMB)hydroelasticity theory,and makes a comparison with the existing methods.[Method]First,a brief introduction of the DMB-based hydroelasticity analysis method is given,followed by procedures for calculating the dynamic response of VLFS under regular waves.A structural stiffness matrix is then defined to model connections with complex forms in VLFS.Corrections are made to the relationship between the forces of two lumped masses and their displacements,obtaining a revised structural stiffness matrix and excitation force matrix,and solving the new hydroelastic equations.Finally,the varying trends of the structural dynamic response of VLFS against different bending stiffness by four methods are explored,and the corresponding reasons for their response differences are analyzed.[Results]The results show that all four methods are capable of precisely predicting the hydroelastic response of VLFS with complex forms of interconnection.[Conclusion]The methods in this paper extend the application of the DMB-based method in predicting the dynamic response of non-continuous VLFS,such as multi-hinged VLFS or VLFS with fracture places.