Pressure vessels are subjected to deterioration and damage, which can significantly reduce their strength and loading capabilities. Among several procedures nowadays available to repair damaged steel pipelines, composite-repairing systems have become popular over the past few years to restore the loading capacity of damaged pipelines. This study reports a numerical-experimental investigation performed for a composite-repaired pipeline made of API 5L X60 steel. An experimental burst test was carried out on a 4 m long pipe section, closed by two lateral caps, and tested up to failure by means of high-pressure water. In parallel, the test was numerically replicated through a FEM model of the composite-repaired steel tank, allowing for a cross-comparison of results. It was found that the composite repairing system has almost eliminated both the noteworthy thickness reduction of 80% and the related stress concentrations in the pipe body. These outcomes allow for a better understanding of these repairing procedures in order to drive their subsequent optimization.

In this article, the performance of different geometries of specially designed fixation miniplates for mandibular symphyseal fracture is evaluated by investigating the effect of geometrical parameters on the biomechanical stability of the fracture. Experimental cone beam computed tomography (CBCT) images were used to generate and simulate the mandible model. Two novel miniplate geometries, including rectangular and elliptical designs, are presented to achieve better biomechanical performance than conventional design. Performance of each geometric design is evaluated in six different dimensional parameters to determine the appropriate parameters for the new miniplate designs. Three-dimensional stress analysis is performed to investigate the mechanical behavior of the novel miniplates, and the results are compared with the classic miniplate. The results reveal that the relative displacement in the symphysis bone of the fractured mandible area fixed by the new rectangular and elliptical designs is reduced 9.55 % and 15.4 %, respectively. In addition, the novel designs for miniplates reduce the number of screws by two in comparison to classic miniplates. The biomechanical advantages observed, such as reduced relative displacement and a decreased number of screws (implying less surgical trauma to the bone), suggest that the novel miniplate designs hold the potential to contribute to more favorable clinical outcomes, possibly influencing aspects such as patient recovery time. Findings of this research provide a foundation for future experimental and clinical investigations of potential clinical benefits.