Mechanical Engineering / Makina Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4129

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2004 - 200912010 - 20172

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Author: search.filters.author.Taşdemirci, AlperPublisher: search.filters.publisher.SAGE Publications Inc.

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Now showing 1 - 3 of 3
  • Article
    Citation - WoS: 6
    Citation - Scopus: 7
    Experimental and Numerical Investigation of the Effect of Interlayer on the Damage Formation in a Ceramic/Composite Armor at a Low Projectile Velocity
    (SAGE Publications Inc., 2017) Taşdemirci, Alper; Tunusoğlu, Gözde
    The damage formation in a multilayered armor system without and with an interlayer (rubber, Teflon, and aluminum foam) between the front face ceramic layer and the composite backing plate were investigated experimentally and numerically. The projectile impact tests were performed in a low-velocity projectile impact test system and the numerical studies were implemented using the nonlinear finite element code LS-DYNA. The results of numerical simulations showed that the stress wave transmission to the composite backing plate decreased significantly in Teflon and foam interlayer armor configurations. Similar to without interlayer configuration, the rubber interlayer configuration led to the passage of relatively high stress waves to the composite backing plate. This was mainly attributed to the increased rubber interlayer impedance during the impact event. The numerical results of reduced stress wave transmission to the backing plate and the increased damage formation in the ceramic front face layer with the use of Teflon and foam interlayer was further confirmed experimentally.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 7
    The Effect of Perforations on the Stress Wave Propagation Characteristics of Multilayered Materials
    (SAGE Publications Inc., 2016) Taşdemirci, Alper; Kara, Ali
    The 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: 24
    Citation - Scopus: 28
    Stress Wave Propagation Effects in Two- and Three-Layered Composite Materials
    (SAGE Publications Inc., 2004) Taşdemirci, Alper; Hall, Ian W.; Gama, Bazle A.; Güden, Mustafa
    Multilayer materials consisting of ceramic and glass/epoxy composites have been subjected to high strain rate compression testing using the Split Hopkinson Pressure Bar. The samples were extensively strain gaged so that dynamic data were generated directly from the samples during testing. Output data from the experiments were compared with numerical simulations of the same experiments and good agreement was noted. It was found that the stress distribution within samples was quite inhomogeneous and that stresses were highest in the region of the bar–sample interface. The presence of a rubber interlayer between the ceramic and glass/epoxy decreased the stress in both components but dramatically increased the degree of stress inhomogeneity.