The effect of deformation rate on the damage tolerances of nomex honeycomb cored composite sandwiches için kapak resmi
The effect of deformation rate on the damage tolerances of nomex honeycomb cored composite sandwiches
Başlık:
The effect of deformation rate on the damage tolerances of nomex honeycomb cored composite sandwiches
Yazar:
Çelik, Muhammet, author.
Yazar Ek Girişi:
Fiziksel Tanımlama:
xi, 78 leaves: charts;+ 1 computer laser optical disc.
Özet:
The impact response and damage tolerance of E-glass/epoxy faces and Nomex honeycomb core sandwich were determined experimentally at different velocities (0-40 ms-1). Concentrated quasi-static indentation force (CQIF), low-velocity impact (LVI) and high-velocity impact (HVI) tests were performed sequentially using a universal test machine, a drop weight tester and a modified Split Hopkinson Pressure Bar system using a hemispherical indenter with a diameter of 16 mm. Velocity was increased by reducing the mass of the indenter in HVI. HVI was performed at the same impact energies (3-33 J) as LVI. Although CQIF and LVI showed similar damage modes, front face damage initiation and perforation occurred at higher energies in LVI, which was ascribed to the rate sensitivity of the face material. When the front face was penetrated at 10 J, residual strength was found to reduce 60%. The flexural waves and core shear were observed to become dominant above 40 J. Barely visible damage was identified below 10 J with a dent depth less than 1 mm, the damage area less than 50 mm2 and an NRS of ~0.8. Visible damage occurred between 50-400 mm2 damage areas when the front face was perforated (10-39 J). Discrete source damage was detected between 400-800 mm2 where fullpenetration and core shear occurred (>40 J). Although damage areas in HVI were smaller than those of LVI at the same energies, compression after impact tests showed almost no effect of velocity on NRS, except HVI tested coupon showed a slightly higher mean NRS at 5.5 J.
Yazar Ek Girişi:
Tek Biçim Eser Adı:
Thesis (Master)--İzmir Institute of Technology: Mechanical Engineering.

İzmir Institute of Technology: Mechanical Engineering--Thesis (Master).
Elektronik Erişim:
Access to Electronic Versiyon.
Ayırtma: Copies: