PSI - Issue 83

Iman Onsa et al. / Procedia Structural Integrity 83 (2026) 280–285

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2.2. Materials: L-80 and P110 casing grades API 5CT L-80 and P110 were simulated for the two casing material cases. The tool joint was assumed rigid (or hardened steel) so that the focus of wear prediction could be on the casing surface, in accordance with the modelling assumptions adopted for the contact-wear simulations. The main difference between L-80 and P110 in the wear model is the hardness value used in Archard’s law, which describes the resistance to material removal at the contact interface. Materials properties are shown in Table 1 2.3. FE Mesh A refined mesh was used on the casing contact surface to resolve the contact pressure gradients. Inflation layers were used in the contact region, and tetrahedral linear elements with a 3mm element size were used to balance accuracy and runtime. A mesh sensitivity check was performed to ensure that the wear trends were stable with respect to discretization. The geometry and mesh are shown in Figure 1.

Figure 1: Geometry and Mesh of the casing and TJ

2.4. Boundary Conditions The casing was fixed in position in the global coordinate system, while the tool joint was rotated through defined angular velocities (115 and 207 rpm) [7]. There were two parametric sweeps completed. The load sweep consisted of: normal/side load combinations of 1000(N) and 1400(N), using a constant speed of 115rpm [4]. The analysis was done under the conditions of low speed and high load, and high speed and low load to find which has more effect on wear. 2.5. Contact and wear model Surface-to-surface contact was defined by using the *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE contact type, using a penalty-based algorithm appropriate for explicit analysis. Wear calculations were calculated based on Archard's law [8], wear being proportional to contact pressure, sliding distance, and scaled by the wear