含局部减薄缺陷弯管的极限载荷研究本科生毕业（设计）论文.doc

2013 届 毕 业 设 计（论文） 题 目： 含局部减薄缺陷弯管的极限载荷研究 学 院： 机械与动力工程学院 专 业： 过程装备与控制工程 班 级： 控制0904班 2012.12 — 2013.06 2013年6月 含局部减薄缺陷弯的极限载荷研究弯管是管道系统的主要构件，在受压管道系统中受载复杂，是系统中的薄弱环节。局部减薄是弯管中常见的缺陷之一，国内对此类缺陷的研究主要针对直管，对弯管的局部减薄的研究少，而且目前对局部减薄管道的研究也限于，对含局部缺陷压力管道的极限载荷及失效评定却少有研究，导致在实际工程应用中对含局部缺陷压力管道的失效评定缺乏理论依据。ailure assessment of pressure pipe with local wall thinning defect under the action of torque load in the practical engineering application. Finite element analysis was adopted in this paper. It studied the limit load analysis of elbow with local wall thinning defects under the action of single internal pressure, single bending moment, single torque, and studied in detail the effect of local wall thinning defects on the limit load. It provided LTA engineering evaluation with a strong basis.In this paper, the main research contents and conclusions are as follows: This paper established the three-dimensional finite element models of elbows with local wall thinning defects and given finite element pre-processing and calculation procedures suitable for this task. For local thinning elbow under internal pressure, affecting its carrying capacity is mainly the depth of localized thinning, the axial length followed, the hoop length with minimal impact on the carrying capacity; for local thinning elbow under closing moment, affecting its carrying capacity is mainly the hoop length of localized thinning, the depth followed, the axial length with minimal impact on the carrying capacity; for local thinning elbow under torque, affecting its carrying capacity is mainly the axial length of localized thinning, the hoop length followed, the depth with minimal impact on the carrying capacity. For elbow with LTA in extrados, finite element results show that when elbow with local thinning subjected to torque, the loaded section is always at first to reach the limit state, and local thinning areas and other parts