Designing and maintenance of pipeline cable bridge with dynamic loads is complex because this problem belongs to the geometrically nonlinear problems. Analysis shown that existing mathematics models of cables have restrictions in use and we can’t use these cable models for dynamic loads calculations of cable-suspended pipeline bridge. Movement, produced by motion of inspection pig inside pipeline is an example of such dynamic loads. During its motion through the pipeline cable bridge the inspection pig induces additional stresses in pipeline due its weight and finite velocity which induces the vibration of the bridge. Its stress state assessment requires a lot of modeling, measuring and calculating actions to be done. First of all the initial static stress state of the cable bridge should be evaluated. It depends on the existing tension forces in the cable elements. They approximately were derived from the optical measurement of their geometrical curvatures with accounting for known weight density of the cables. Then, existing software tool for piping stress calculation “3D Pipe Master”, which operates by 12 degrees of freedom in pipe elements, was modernized to be able to take into account the geometrically nonlinear behavior of 6 d.o.f. cable elements. The equations which relate the elongations and rotations of cable elements with tension forces in cables are written in the form convenient for application of the transfer matrix method in the linearized iteration procedure which adjusts the measured displacements of the elements of the bridge with calculated one. In this way the initial tension forces in cables, in particular, and the bridge state, in general were determined. The dynamic part of the problem is solved by expansion in terms of natural frequencies eigenfunctions. Given inspection pig velocity calculation allows to determine the time dependence of generalized loads for each of natural vibration mode as product of the pig weight multiplied by mode shape displacement in point of pig position at the given time moment. Eventually the technique of Duhamel integral is used to calculate the dynamic behavior of the bridge for each natural mode of vibration. Two examples of dynamic stress calculation are considered. First is primitive one and relate to calculation joint interaction pipeline and cable system at dynamic loading. The second example concerns dynamic calculation pipeline cable bridge through the river Svicha during movement inspection pig. This bridge consists of two support, two parallel pipelines (1220×15) with bends and cable system. Analysis shown possibility uses “3D Pipe Master” software for the solving problems of durability pipeline cable bridge any complexity in the conditions of static and dynamic loading.
- Pipeline Division
Assessment of Stress-Displacement State of Cable Suspended Pipeline Bridge During Inspection Pig Motion
- Views Icon Views
- Share Icon Share
- Search Site
Orynyak, I, Burak, I, Okhrimchuk, S, Novikov, A, & Pashchenko, A. "Assessment of Stress-Displacement State of Cable Suspended Pipeline Bridge During Inspection Pig Motion." Proceedings of the 2016 11th International Pipeline Conference. Volume 2: Pipeline Safety Management Systems; Project Management, Design, Construction and Environmental Issues; Strain Based Design; Risk and Reliability; Northern Offshore and Production Pipelines. Calgary, Alberta, Canada. September 26–30, 2016. V002T02A010. ASME. https://doi.org/10.1115/IPC2016-64197
Download citation file: