潜艇结构锥柱结合壳损伤容限研究

Study on damage tolerance of submarine cone-cylinder pressure shell structure

损伤容限与耐久性的结合体现了现代潜艇结构延长寿命、提高可靠性和降低维修成本的综合要求。损伤容限分析的关键问题是正确估算剩余寿命。本文以断裂力学为理论基础,通过对带有初始裂纹的潜艇典型焊接节点模型的剩余寿命有限元分析,将计算结果和试验结果相比较,考核剩余寿命有限元分析方法的可靠性,从而对有初始缺陷或裂纹的疲劳热点区域——潜艇锥柱结合壳进行剩余寿命有限元估算,在此基础上进行潜艇锥柱结合壳损伤容限研究。并对具有不同尺寸的初始裂纹结构的剩余寿命进行有限元分析,确定潜艇在交付使用和检修时的损伤容限尺寸。

Damage tolerance and durability meets the comprehensive requirements of prolongation of service life,high reliability and low maintenance cost of modern submarines.The key of analysis of damage tolerance is to estimate the residual fatigue life correctly.A experiment on typical welded joints with the initial crack is carried out,and the residual fatigue life analyzed with FEM based on the fracture mechanics is compared with the test result,so the reliability of calculating of residual fatigue life with finite element method is examined.On the hotspot of fatigue, the residual fatigue life of submarine cone-cylinder pressure shell structure with initial crack is calculated with finite element method. According to this, damage tolerance of submarine cone-cylinder pressure shell structure is studied. Moreover, the residual fatigue lives of the structure with initial cracks of different size are analyzed with finite element method; consequently the size of damage tolerance is determined while submarine is available to the user and overhauled.