RESUMEN
While most academic studies focus on the properties of cured joints, this research addresses the manufacturing process of hybrid joints in their uncured state. Hybrid joints that combine adhesive bonding with pre-tensioned bolts exhibit superior mechanical performance compared to exclusively bonded or bolted joints. However, the adhesive flow during manufacturing in hybrid joints often results in a nonuniform adhesive thickness, where obtaining an exact thickness is crucial for accurate load capacity predictions. This paper presents experiments involving three different adhesives, providing precise measurements of the adhesive layer thickness distribution, which served as a reference when evaluating and validating the subsequent numerical predictions. The numerical predictions were performed using computational fluid dynamics (CFD) to model the flow behavior of the adhesives during the bonding process and their interactions with the metal substrates. The CFD predictions of the adhesive layer thickness showed good agreement with the experimental data, with the relative differences between the average experimental and numerical thickness values ranging from 4.07% to 27.1%. The results were most accurate for the adhesive with sand particles, whose particles remained intact, ensuring that the adhesive's rheology remained unchanged. The results highlight the importance of the rheological behavior of the adhesive in the final distribution of the adhesive layer thickness, thereby expanding the understanding of these joints.
RESUMEN
Lateral subluxation of the femoral head is one of the poor prognostic factors of Legg-Calvé-Perthes disease. The aim of this study was to investigate the cause of lateral subluxation of the femoral head on the basis of the changes over time on MRI. Twenty-four patients with unilateral Legg-Calvé-Perthes disease were analyzed retrospectively. Lateral subluxation was measured as the tear drop distance on radiographs. We focused on joint fluid, medial articular cartilage thickening, and abnormal lesion on MRI. Lateral subluxation continued significantly in patients with poor results. Among the MRI findings, the presence of an abnormal lesion was associated significantly with the continuous lateral subluxation.