中文摘要：

管道机械损伤中最常见的类型是凹陷,这些缺陷是导致管道失效的主要原因,为深入研究其对管道安全的影响,建立符合实际工况的计算模型是有必要的。前人通过棍压模型和球压模型重点对有凹角的凹陷进行了较为全面的分析研究。本文在给出有凹角和无凹角凹陷的尺寸判别方法后,分析管道上实际检测数据发现无凹角凹陷在管道上分布较多,提出无凹角凹陷的计算模型—环向棍压模型。通过有限元软件模拟检测的凹陷尺寸验证了模型的准确性。最后,分析环向棍参数对模拟凹陷的尺寸影响,结果表明：同一深度的凹陷,可以通过改变环向棍的曲率半径去改变凹陷的长宽尺寸,以满足对实际工况中随机尺寸凹陷的模拟;进一步研究发现,无凹角凹陷对管道安全的影响有着不可忽视的作用。

英文摘要：

The most common type of pipe mechanical damage is dent defect,which is a major cause of leading to pipeline fatigue rupture. For further research on the security of the pipelines,it is necessary to establish a calculation model serving actual conditions. Predecessors have carried on the comprehensive analysis of dent with concave angle by stick model and spherical model. A distinguishing method between dent with concave angle and without concave angle is proposed in this paper,The online detection data of pipeline shows that the dent without concave angle is in the majority. Then calculation model of dents without concave angle—hoop stick model is presented,which is verified by Finite Element simulating the actual dimension.Finally,influence of the stick parameters to result of the dent simulation is studied. It turns out that the simulation of differentsized dents without concave angle can be achieved by changing the curvature radius of hoop stick. Further research also showed that dent without concave angle on pipeline safety cannot be ignored.