Abstract:
Mechanical properties, internal condition, and fracture risk of structural components can be effectively assessed by noninvasive techniques, which are primarily favored for their efficiency and speed. This study presents comprehensive noninvasive evaluations of slender graphite rods and, significantly, the human thoracolumbar spine, providing crucial biomechanical insights. An experimental approach was developed for graphite rods, complemented by numerical approaches for both graphite rods and the human thoracolumbar spine. For the graphite rods, transient elastic impact was employed as a nondestructive testing method to detect internal cracks that may occur during manufacturing, with wave theory used for solid rods. Subsequently, numerical models, specifically finite element models developed using ANSYS commercial code, were utilized to determine the response of rods containing cracks. Experiments on graphite rods, both with and without cracks, were conducted to validate these predictions. For the human thoracolumbar spine, the study developed a robust three-dimensional finite element model encompassing vertebral bodies, intervertebral discs, ligaments, facet joints, and spinal implant systems, focusing on addressing the biomechanical challenges associated with scoliosis. This advanced FE model, constructed using the commercial finite element analysis (FEA) software ABAQUS, was subjected to different physiological loading conditions, including combined loading due to muscle forces and body weight, which were applied to simulate various postures. This biomechanical investigation aimed to provide insights into spinal mechanics, particularly in the context of internal fixation techniques used for scoliosis correction. The findings from these noninvasive and computational evaluations contribute significantly to understanding the structural integrity of materials and the complex biomechanics of the human spine, with implications for improving the design of spinal implant systems and providing more effective and detailed treatment for scoliosis.
