الفهرس 
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Abstract
Mineral tubes and pipes are used in a wide range of engineering applications, including the automotive, chemical, nuclear, and petroleum industries. Thus, the manufacturing and application of those pipes necessitate a thorough knowledge of their mechanical properties. Furthermore, reliable numerical modeling of forming processes necessitates accurate models of material behavior, including such deformation, anisotropy, and failure. This would support the creation of suitable designs and ensure the secure operation of systems. Moreover, the most frequent type of failure for pressurized tubes and pipes is longitudinal cracks because internal pressure is the main factor. Therefore, the mechanical behavior of tubular materials in the transverse direction should be determined because of these considerations. In this thesis, ring elongation was used as the materials testing technique to conduct a thorough investigation into the mechanical properties of tubular materials in the hoop direction. The ring elongation testing technique (RETT) was initially subjected to extensive numerical analyses, including analytical and finite element analyses (FEA). FEA were performed on 2D and 3D ring models using the FEA commercial package (ABAQUS). This is to forecast the full deformation behavior of those rings models materials and to investigate the impact of loading pin diameter, ring dimensions, and ring shape on the outcomes of the ring elongation test. Additionally, analytical analyses were developed to calculate the elastic properties (young’s modulus and yield strength) in the hoop direction. Subsequently, axial tensile test experiments were then performed to validate the RETT results. Eventually, RETT experiments were carried out on the full ring specimens and ring specimens with two reduced sections. FEA successfully predicted the full deformation behaviors of the ring materials. Loading pin diameter has almost no effect on the RETT results. In the RETT, notched and dog bone-shaped ring specimens can be used to overcome ring specimen failure near the loading pin. Additionally, the dog bone-shaped ring specimen can be used to obtain stress-strain data by acquiring gauge length and cross-section area for the ring specimen. Directly from the RETT experimental results, both curved and straight beam displacement and stress formulas successfully predicted young’s modulus and the hoop yield strength with high accuracy. Finally, the hoop plastic stress-strain results were also successfully determined directly from the RETT experimental results with high accuracy. This is when compared to the results obtained from the standard axial tensile test.