Archive of Applied Mechanics

Božić, Željko; Schmauder, Siegfried

doi: 10.1007/s00419-019-01531-2pmid: N/A

Chang, Kyong-Ho; Kang, Seong-Uk; Wang, Zhen-Ming; Muzaffer, Shazia; Hirohata, Mikihito

doi: 10.1007/s00419-019-01513-4pmid: N/A

The results of a fatigue finite element analysis (FEA) based on the continuum damage mechanics of welding tubular members are presented. The effects of welding joint type on fatigue life and crack location were investigated. The initial mechanical state of a welded tubular member was simulated to identify initial welding imperfections such as welding residual stress and welding deformation using three-dimensional (3D) thermal elasto-plastic large-deformation FEA. The temperature history, which was simulated by using a 3D nonsteady heat conduction FEA, was used in the thermal elasto-plastic analysis as the initial thermal load. The welding joint type effects on fatigue life and crack location of a tubular member were investigated using 3D fatigue FEA. The effect of welding joint type on fatigue strength was also observed. It clarified that fatigue life was different depending on the joint type. Moreover, crack initiation and crack propagating direction of welded T- and K-type tube members were investigated. It was found that crack initiation takes place at different positions depending on the welding joint type. The 3D fatigue FEA method presented here is helpful in identifying fatigue crack location and ascertaining fatigue life.

Amara, M.; Bouledroua, O.; Hadj Meliani, M.; Azari, Z.; Tahar Abbess, M.; Pluvinage, G.; Bozic, Z.

doi: 10.1007/s00419-019-01518-zpmid: N/A

On the basis of the calculation of the stress field around the corrosion-damaged areas on the external part of a pipeline used for the transport of hydrocarbons, an analysis of the effect of the level of post-repair burst pressure by composite patches is proposed. This work examines some points of views on the burst pressure standards calculation on real test on pipeline with external corrosion defects. This study divided to three parts. In the first, an inspection is given for a real pipe exhibiting a surface corrosion defect. The corrosion defects were collected and divided into six important defects. The internal pressure has increased to the burst of pipeline. The second part illustrated a numerical study of the defects interaction effect on the safety of pipeline. The third part of this study is showing a finite element analysis of repaired pipe using the composite repair; we will study the effect of the composite sleeve number on the structural integrity of the pipe. The principle of failure assessment (FAD) diagram is described, and particularly, the definition of the non- dimensional applied crack tip loading $${k}_{\mathrm{r}}$$ k r , the non- dimensional net applied stress (or load) $${S}_{\mathrm{r}}$$ S r or $${L}_{\mathrm{r}}$$ L r is given. The interest lays in the fact that many pipes defects are scratch or gouge types. In the FAD, results demonstrated that the composite repair method does not affect the interpolation curve and, at the same time, had a slightly effect on the function point.