低温环境下海洋平台管节点的断裂力学分析

Fracture mechanical analysis of riser nodes of offshore platform at low temperature.

从冬季导管架海洋平台服役的工程实际出发 ,分析研究了管节点的低温疲劳裂纹扩展速率 ,给出了管节点表面裂纹扩展的主要控制变量应力强度因子的计算公式。经过对比和计算 ,得出了在 -2 5℃低温环境下管节点da/dN -ΔK关系式中材料参数c和m的具体值 ,为冬季海洋平台管节点剩余疲劳寿命的估算和安全性评估提供了依据。

Based on the actual working condition of offshore platform risers in winter, the extension rate of fatigue cracks (da/dN) in riser nodes at low temperature is investigated. The equation for calculating the main control variant ΔK of surface crack extension —— the stress strength factor is given. By means of comparison and calculation, the values of material parameters c and m in the relational expression of the riser node at -25℃ (da/dN—ΔK) are obtained. The calculation provides a basis for the estimation of the residual fatigue life of riser nodes at low temperature.