针对基于振动的数值仿真、振动实验预测方法的不足,基于振动的水下圆锥壳临界载荷预报具有结构无损的优势,提出了基于波传播法的水下圆锥壳失稳载荷的理论求解方法。通过建立静水压力下圆锥壳声-固耦合振动方程,并使用波传播法和Galerkin法求解不同静水压下的频率特性。在处理耦合面处流体声载荷时将锥壳分解为多个柱壳微段的流体载荷的叠加。通过对水下圆锥壳的固有频率和静水压力的关系研究,得出静压与固有频率平方近似呈线性关系这一重要结论,并通过线性拟合求出临界载荷。结果对比证实了方法的正确性,且具有简便、计算量小、易于参数优化的优点。
In regard to the deficiencies in numerical simulation based on vibration and the method to predict vibration experiment,by taking advantage of the prediction for clinical load of vibration-based submerged conical shell that is nondestructive,this paper proposes a theoretical method to solve the collapsing load of a submerged conical shell based on wave propagation approach. It first establishes the acoustic-solid coupling vibration equation under the hydrostatic pressure,and solves the frequency characteristics under different hydrostatic pressure by wave propagation approach and Galerkin method. The data of natural frequencies of the system under different hydrostatic pressures is obtained after solving the coupled equation. Simultaneously,conical shell is divided into several microsections of cylindrical shells which are superposed when dealing with fluid acoustic loading on the coupling surface.An important conclusion is obtained by the study of relationship between natural frequencies and hydrostatic pressures,which indicate that there is an approximate linear relationship between squared natural frequencies and hydrostatic pressures. In addition,critical load can be solved by linear fitting. The result obtained from present approach is correct,showing good consistency with those from classical theory. Furthermore,present approach has the advantages of simpleness,less calculation and easy to optimize parameter.