Mechanical Engineering / Makina Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4129
Browse
2 results
Search Results
Article Citation - WoS: 6Citation - Scopus: 7The Effect of Perforations on the Stress Wave Propagation Characteristics of Multilayered Materials(SAGE Publications Inc., 2016) Taşdemirci, Alper; Kara, AliThe effect of perforated interlayers on the stress wave transmission of multilayered materials was investigated both experimentally and numerically using the Split Hopkinson pressure bar (SHPB) testing. The multilayer combinations consisted of a ceramic face plate and a glass/epoxy backing plate with a laterally constrained low modulus solid or perforated rubber and Teflon interlayer. The perforations on rubber interlayer delayed the stress rise time and reduced the magnitude of the transmitted stress wave at low strains, while the perforations allowed the passage of relatively high transmitted stresses at large strains similar to the solid rubber interlayer. It was concluded that the effect of perforations were somewhat less pronounced in Teflon interlayer configuration, arising from its relatively low Poisson's ratio. It was finally shown that SHPB testing accompanied with the numerical simulations can be used to analyze the effect of compliant interlayer insertion in the multilayered structures. © The Author(s) 2015.Article Citation - WoS: 30Citation - Scopus: 36Crushing and Energy Absorption Characteristics of Combined Geometry Shells at Quasi-Static and Dynamic Strain Rates: Experimental and Numerical Study(Elsevier Ltd., 2015) Taşdemirci, Alper; Şahin, Selim; Kara, Ali; Turan, Ali KıvançThe quasi-static and dynamic crushing response and the energy absorption characteristics of combined geometry shells composed of a hemispherical cap and a cylindrical segment were investigated both experimentally and numerically. The inelastic deformation of the shells initiated with the inversion of the hemisphere cap and followed by the axisymmetric or diamond folding of the cylindrical segment depending on the loading rate and dimensions. The fracture of the thinner specimens in dynamic tests was ascribed to the rise of the flow stress to the fracture stress with increasing strain rate. The hemisphere cap absorbed more energy at dynamic rates than at quasi-static rates, while it exhibited lower strain rate and inertia sensitivities than the cylinder segment. For both the hemisphere cap and the cylinder segment, the inertial effect was shown to be more pronounced than strain rate effect at increasing impact velocities. © 2014 Elsevier Ltd.