腐蚀裂纹损伤下船舶管路抗冲击时变剩余强度研究

Research on the residual strength of ship pipeline on the shock resistance under corrosion and crack damage

舰艇管路系统对冲击载荷作用非常敏感,遭受冲击载荷后通常会引起管路系统应力或变形过大而破坏,而裂纹和腐蚀作为常见的一种损伤缺陷导致结构承载力下降,降低管路系统的使用寿命。因此针对典型管路系统管路段,建立仿真精度较高的典型管路有限元模型,对典型管路系统管抗冲击性能进行分析;根据仿真分析结果,确定管路结构强度的薄弱节点或分段(称之为关键节点或关键结构)作为裂纹扩展的初始点。基于管路系统腐蚀和裂纹的发展规律和有限元计算方法,建立管路系统时变剩余强度预报模型,发展一种分别计及腐蚀、裂纹2种因素作用下,舰艇管路系统在三向冲击载荷作用下剩余强度的计算方法和实现流程。在此基础上,分别研究裂纹损伤、腐蚀损伤在不同服役年限下冲击载荷对舰艇管路时变剩余强度的影响规律。

The pipeline system is very sensitive to the impact load. Pipeline system will be damaged due to large stress or deformation. The crack and corrosion, as a kind of common damage, lead to the decrease of the bearing capacity of the structure and reduce the service life of the pipeline system. So, the typical pipeline model with high simulation precision is established, and the impact resistance performance of typical pipeline system is analyzed; According to the simulation res- ults, it is determined that the weak node or subsectioncalled as the key node or key structureof the pipeline structure is the initial point of the crack growth. Based on the rule of development of corrosion and crack in pipeline system and the finite element calculation method, the residual strength prediction model of pipeline system is established. The calculation method of residual strength of ship piping system and the realization flow are developed under the action of two kinds of factors, which are corrosion and crack. On this basis, the influence of crack damage and corrosion damage on the residual strength of the pipeline is studied.