Abstract:

The data acquisition and modeling of the depressed pipe were carried out using a 3D scanner, and the residual strength at the depressed pipe was evaluated; based on the modeling, the finite element analysis of the 3D modeled pipe containing the depression was carried out using ABAQUS software, and the stress?strain analysis was carried out using numerical simulation; the geometric deformation detection method was used to detect the depressed pipe, and the stress?strain at the depressed pipe was calculated and analyzed. The load?bearing capacity of the recessed pipe was evaluated; a comparative analysis was conducted for both cases of the pipe with/without internal pressure. The results show that the maximum Von Mises stress at the depression differs greatly between the two cases with/without internal pressure; in the case with internal pressure, the maximum Von Mises stress is located at the perimeter of the pipe depression rather than at the depression; in the case with internal pressure, the maximum equivalent force in the area near the depression is 22.6 MPa, while the maximum equivalent force in the case without internal pressure is 14.8 MPa. The maximum Von Mises stress applied to the pipe is distributed in the deepest part of the depression with a value of 710.3 MPa, and the maximum equivalent force becomes 8.99%, which is distributed in the inner part of the depressed pipe when the downward displacement constraint of 50 mm is set in the indenter. In engineering applications, the 3D scanning technology can be used to obtain the contour of the pipe depression more quickly, and the output data can be used to provide technical support for subsequent stress?strain analysis, pipe evaluation, and rehabilitation.

Key words: Pipe depression, 3D scanning, Geometry detector, Residual life, Engineering application

摘要：

利用三维扫描仪对凹陷管道进行数据采集及建模，评价了凹陷管道处的剩余强度；在建立模型的基础上，运用ABAQUS软件对三维建模的含凹陷管道进行有限元分析，采用数值模拟的方法进行了应力应变分析；通过几何变形检测方法对凹陷管道进行检测，计算并分析凹陷管道处的应力应变，对凹陷管道的承载能力进行了评估；对管道有/无内压两种情况进行了对比分析。结果表明，在有/无内压两种情况下，凹陷处的最大Von Mises应力相差较大；在有内压情况下，最大Von Mises应力位于管线凹陷处的周边，而不是凹陷处；在有内压情况下，凹陷附近区域的最大等效应力为 22.6 MPa，而无内压情况下的最大等效应力为14.8 MPa；压头设置50 mm的向下位移约束，管道所受的最大Von Mises应力分布在凹陷最深处，其值为710.3 MPa，最大等效应变为8.99%，分布在凹陷管道的内侧。在工程应用中，采用三维扫描技术可以更快捷地得到管道凹陷的轮廓，利用输出数据为后续的应力应变分析、管道评价以及修复提供技术支持。

关键词: 管道凹陷, 三维扫描, 几何检测器, 剩余寿命, 工程应用