【摘要】 基于长输管道中弯管壁厚在经向与周向存在不均匀性,提出了一种新的弯管模型。通过对比内压作用下均匀壁厚弯管平均应力的有限元模拟值与理论值,验证了弯管建模方法的可靠性。运用新的弯管建模方法,得到了不均匀壁厚弯管在内压与面内弯矩联合作用下的应力分布规律。运用应力分离技术分析了不均匀壁厚弯管薄膜应力与弯曲应力的分布特征。研究结果表明,不均匀壁厚对弯管薄膜应力的分布有较大影响;适当的壁厚不均匀有利于增强弯管承受内压的能力;不均匀性壁厚弯管进行强度校核时,应适当增大经向和周向的弯曲应力增强系数。研究结果可为实际弯管的设计制造和安全评价提供依据。更多还原

【Abstract】 Considering the non-uniform wall thickness of actual elbow along the longitudinal and circumferential direction in long distance pipeline,a new elbow model has been proposed. Compared the finite element simulation with the theoretical value of mean stress in uniform thickness elbow under internal pressure,the reliability of the modelling method has been proved. Using the new model,the stress distribution of the elbow under the combined action of internal pressure and in-plane bending moment has been obtained. Through stress separation technology,the distribution characteristics of membrane stress and bending stress on the non-uniform wall thickness elbow has been analyzed. The results show that,the non-uniform wall thickness has a great influence on the membrane stress distribution. Appropriate wall thickness non-uniformity is helpful to enhancing the capacity of elbow bearing internal pressure. The longitudinal and circumferential bending stress enhancement coefficient should be increased appropriately during stress check of actual elbow. The results could provide bases for the design,manufacturing and safety assessment of actual elbow.更多还原