大深度潜器耐压壳结构破坏机理分析与影响因素研究

With the development of deep ocean and the research of larger depth of submersible,many complex problem needed to face such as failure mechanism in limit state，nonlinear influence factor and moderately thick shell.Research on the complex behavior of pressure hull structure and current design rules were fall behind real engineering.This project based on vector form intrinsic theory, structure nonlinear theory and error analysis theory.The mechanical behavior and main influence factor of submersible pressure hull in deep sea by using modified modulus method, the least-square method and inverse analysis method.Firstly,based on vector form intrinsic theory, derived shell element formulas and procedure for vector form intrinsic Finite Element Method. Through these, the whole collapse process is simulated from diving into the water at the beginning to deep sea and limit state to the end. Secondly, based on analysis of the nonlinear behavior,to reveal the influence parameters of structure and sensitivity, structure parameters affecting the ultimate strength of the pressure hull and the coupling relationship between parameters were studied.At last, the rules for checking the limit state are established. Developing and improving the analyzed method which is effective in calculating the ultimate strength for pressure spherical hull of deep sea submersible, assure the applicability of this method, and attained its error range. This project will supply theory and method to research ultimate strength of pressure spherical hull for submarine.The application of this project is good for accurately predicting and simulating the failure behavior of pressure hull structure.The conclusion of this project will ensure theoretical results and simulate technique safely and reliable to guide the structural design.

随着海洋深海的开发研究，潜器下潜深度进一步增加，需要面临耐压壳极限状态力学行为研究、非线性因素、中厚壳等难题。针对深潜器耐压壳结构复杂力学行为分析与设计规范相对于实际工程发展滞后的现状，本项目拟以向量式力学理论、结构非线性理论、误差分析理论为依据，采用改进模量算法、最小二乘法及反演分析法对耐压壳结构的破坏机理与主要影响参数进行理论研究。首先，以向量式有限元方法为基础，模拟耐压壳从入水到深海直至极限状态下逐步塌毁的全过程；然后，在分析结构非线性行为的基础上，研究影响耐压壳极限强度的结构参数及各参数耦合关系，揭示影响结构力学性能的关键结构参数和敏感度；最后，建立深潜器耐压壳的极限状态衡量标准，发展并完善中厚度耐压壳极限强度的计算方法。本项目的开展有助于精确预测、模拟耐压壳结构的破坏行为，为耐压壳的设计提供更加系统全面的技术支持，确保理论结果和仿真技术能准确、可靠地指导耐压壳结构的设计。

本项目通过理论推导、数值模拟计算与模型试验相结合的方法，对深潜器耐压壳结构破坏的力学行为、耐压壳极限强度的影响因素及耦合关系进行了分析研究，并对中厚耐压壳的力学特性与计算方法展开研究。现已完成了应用向量式有限元理论模拟结构的非线性力学行为尤其是非线性断裂力学，用于新型的杆件结构并与相关试验结果进行对比。同时，应用随机缺陷模态法对含一致缺陷模态(或低阶缺陷)和局部单一缺陷得到耐压壳极限强度的可靠性进行评估。研究深海耐压球壳模态缺陷的极限强度特性，分析不同参数对模态缺陷的球壳极限强度影响，继续深入研究实际深海环境中耐压壳的承载能力，重点研究不同材料参数(合金、复合材料)、不同长度/半径/厚度/缺陷幅值等因素对圆柱壳极限强度的影响，研究分析不同影响因素对耐压壳极限强度的支配度和灵敏度。同时，增大随机缺陷的样本数(从200增大到1000，再增大到3000)，比较不同样本数对计算结果的影响，分析讨论如何确定最佳样本数目。还从深海生物贝壳的结构造型出发，考虑仿生造型耐压壳结构的构建，进行极限承载力分析，并与常用结构进行对比。以及研究建立深潜器耐压壳的极限状态衡量标准。这些研究目前仍然正在进行中。