A general parametric finite element modeling and stress response analysis methods for pipeline system using the nonconforming solid element

In the dynamic topology optimization design of pipeline system, parametric finite element modeling (PFEM) is needed to improve the model reconstruction efficiency. Taking a typical spatial single pipeline as the research object, this paper innovatively presents a PFEM method of pipeline system based on the newly constructed nonconforming solid (Solid-NC) element. The stiffness and mass matrices of the spatial 8-node Solid-NC element with second-order boundary accuracy are obtained by introducing the node-free displacement items and statics condensation method. The PFEM method of the pipeline body is proposed by selecting the straight-line segment lengths as the pipeline shape control parameters. The PFEM method of the pipeline is described in detail, including the node coordinate solutions of straight-line and curved arc segments based on the direction vector method and vector decomposition method, respectively, and the simulation of the clamp mechanical properties considering the actual pre-tightening state of the clamp. Furthermore, the modal analysis is carried out, the node stress response solution is solved based on the stress smoothing method, and the effectiveness of the PFEM method is verified through experiment. Finally, the mesh quality and model reconstruction efficiency of the PFEM method is analyzed, the results show that the developed PFEM method has higher mesh quality and fast model reconstruction speed, and the model reconstruction time is shortened by 544.5 times at most compared with ANSYS software.