PSI - Issue 77

C.F.F. Gomes et al. / Procedia Structural Integrity 77 (2026) 95–102 Gomes et al. / Structural Integrity Procedia 00 (2026) 000–000

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Strong and stiff adhesives should be considered in applications demanding minimal deformation, such as high pressure pipelines or aerospace structures (Sun et al. 2021). Compliant adhesives offer greater ductility and energy absorption, making them ideal for applications requiring high toughness and resistance to peel ( σ y ) stresses, such as automotive chassis or offshore structures subjected to fluctuating loads (Kadioglu and Adams 2015). The numerical analysis of adhesive joints has become an indispensable tool to predict their behavior and design joints that maximize structural efficiency with minimum weight. CZM find application in bonded joint design due to their ability to accurately predict failure (Barbosa et al. 2019). Other techniques such as Extended Finite Element Method (XFEM), Virtual Crack Closure Technique (VCCT), and phase-field models have emerged as powerful methods to analyze damage evolution and failure mechanisms. XFEM is particularly effective to simulate crack initiation and growth without predefined paths (Omar et al. 2022), while VCCT provides insights into energy release rates critical to understand adhesive fracture (Jokinen et al. 2015). Damage analysis in tubular adhesive joints is particularly challenging due to the combined σ y , shear ( τ xy ), and hoop stresses, influenced by joint geometry, material properties, and loading conditions. Moreover, the energy dissipation mechanisms during failure, such as adhesive plasticity, crack propagation, and interfacial delamination, vary depending on the adhesive type and joint configuration. Oliveira et al. (2021) numerically investigated the torsional behavior of aluminum tubular adhesive joints, analyzing the influence of L O and tube thickness. The Finite Element Method (FEM) was employed with CZM to evaluate adhesive stress distributions, particularly τ xy stress, and to predict the maximum torsional moment ( M m ). The numerical model was validated against experimental data, demonstrating good agreement. Joint strength was significantly influenced by geometric parameters, with the exception of L O . Islam et al. (2022) investigated the structural reinforcement of lean duplex stainless steel tubular members using externally bonded carbon-fiber reinforced polymer (CFRP) plates. Under increasing loads, decohesion originated at the joint edges and propagated toward the midsection, driven by σ y and τ xy stress distributions. The numerical simulations closely matched experimental results, confirming the accuracy of the developed approach. Shi et al. (2022) addressed solid expandable tubular (SET) technology, which is widely used in oilfields. CZM was employed to analyze failure behavior at the rubber-SET interface, supported by a 3D FEM model incorporating casing, rubber, and SET. A friction coefficient of 0.15 minimized expansion force while maintaining sealing capacity. Optimal rubber compression was around 50% of its thickness, with a maximum length of 60 mm to prevent failure. Reducing stiffness and increasing damage initiation strength lowered the risk of cohesive failure, while fracture energy had minimal impact. This study numerically evaluates the performance of overlap tubular joints by comparing three adherend materials and analyzing the effect of L O . A numerical approach based on CZM was used and initially validated against experimental data. The analysis evaluated the adhesive damage process, strength and dissipated energy prediction.

2. Experimental and numerical procedure 2.1. Tubular joint geometry and dimensions

The numerical technique used in this work was initially validated by experimental tests. The tubular joint geometry shown in Fig. 1 was used for validation and in the present numerical study. The values of L O are the main difference between the geometries applied in the validation of the model (20 and 40 mm) and the numerical analysis (between 10 and 40 mm). The other parameters remained unchanged, and their description can be found in Table 1.

Fig. 1. Tubular joint geometry and dimensions.