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Showing 2 results for Zia shamami
Seyed Mahmood Farmani, Mojtaba Zia shamami, Majid Alitavoli,
Volume 24, Issue 8 (August 2024)
Abstract
In this research, the amount of transverse displacement of circular sandwich panels under explosive loading was investigated using the experimental method, and then, by using the Bessel shape function and subtracting the plastic work of the core components and other deformations from the total kinetic energy given to the structure, the relation for the prediction of the transverse displacement of the plates is provided.The experimental tests are grouped by the construction of the sandwich structure, which is 1.2 and 2mm thick steel plating with aluminum tube cores with external diameters of 12 and 16 mm with a cross arrangement and vertically with the same height between the upper and lower plates of the structure. The results obtained from the methods of this research are expressed by presenting the maximum amount of transverse displacement in terms of the distance from the center of the structure and the amount of length change for each of the cores of the structure. It was found that by increasing the volume of the cores in the sandwich structure, the rigidity of the structure does not necessarily increase against a certain applied load. In the investigation of some structures, the effect of the amount of core collapse on the transverse displacement is almost equal to the effect of the thickness of the plate. The average difference of the results is less than 12 %
Behrooz Khodaeipour, Hossein Khodarahmi, Milad Sadeghyazdi, Mojtaba Zia shamami,
Volume 24, Issue 8 (August 2024)
Abstract
Multi-compartment structures are a sort of multi-layer armor widely used to protect naval equipment, due to their high resistance to underwater blasts, simple-tech/low-cost production, and repairability. The present article numerically investigates the contact UNDEX damages of conceptual-construction structures consisting of three metal layers and two mid-compartments. For this purpose, a set of experiments was designed and executed using AUTODYN. The numerical modeling process and outputs were validated with the results of an experimental test. The results showed that all the structures with the same mediums in compartments suffered rupture in their last layer. Structures with air-water mediums did not experience tearing in their last layer if had a St37 midplate. Benefiting from a St37 front plate led to a significant energy absorption increase of 62%. Also, all structures with water-air mediums had excellent resistance performances and presented a meaningful reduction of 49% in the last layer deflection providing a St37 midplate. Furthermore, the comparison of structural performances showed that the structure consisting of Al2024-T3, St37, and St37 layers respectively, and water-air mediums brings forward the most competitive altogether values for the minimum last layer's central deflection of 11.6 mm and maximum energy absorption per areal mass equal to 84.6 J.m2/kg.
