凹陷立管的极限强度和疲劳寿命分析

用MSC.Patran建立三维模型,然后用ABAQUS计算立管的极限强度,用MSC.Fatigue进行全寿命分析。计算与分析结果表明:最大凹陷深度的增加使立管的极限强度和疲劳寿命减少;凹陷区域长度的变化对立管极限强度的影响不大,对疲劳寿命的影响较大;增加立管管壁厚度会提高立管的极限强度,但管壁越厚,凹陷损伤对立管极限强度的影响越大;立管在轴向拉伸力和纵向弯矩共同作用下,只要轴向拉伸力在合适的范围内,凹陷对立管极限强度的影响非常小。

Analysis of Ultimate Strength and Fatigue Life of the Dented Riser

To study the ultimate strength and fatigue life of the dented riser,MSC.Patran is used to build 3D model.The ultimate strength and life cycle of risers are analyzed by ABAQUS and MSC.Fatigue.The results show that： the ultimate strength and fatigue life significantly reduced as the maximum depth of dent increase.The change of the length of dented region had little effect on ultimate strength,but greater influence on the fatigue life.To increase the thickness of the riser will greatly improve the ultimate strength,but the thicker of the wall,the greater influence on the ultimate strength of the dented riser.As long as the axial tensile force within a suitable region,the influence of the dent on the ultimate strength of the riser under combined axial tensile force and longitudinal bending moment is very small.