期刊名称：International Journal of Energy and Environment
印刷版ISSN：2076-2895
电子版ISSN：2076-2909
出版年度：2018
卷号：9
期号：4
页码：1-14
出版社：International Energy and Environment Foundation (IEEF)
摘要：The Oberst beam method is widely using to measure the mechanical and dynamic properties of materials,
such as the Young's modulus, it has been supplying required data for numerical analysis of structures and
this method was been used with a composite materials, that has been consist of two skin layers (steel,
aluminum) between them the core layer. This paper provides a brief description of the Oberst beam method
by applied modal analysis and ASTM E756-05, the impact hammer is used to generate excitation for the
beam and obtain a studied response. The boundary condition (Fixed-Free) was applied, it uses three
different lengths beams. It was applied this technique in this current work for the two parts. The first part
include a composite beam that consists of two skins (Galvanized steel) between them a layer of
Polyurethane (PU) Rigid foam core. The second part skin was separated from the core of a composite
material beam in (470) mm length beam. It has been obtaining the Young's Modulus for both core and
skins over a frequency range of (30-1000) Hz. And compared results between (Experimental and
Theoretical) by using finite element method (FEM). Found in low frequencies, the value of the Young's
Modulus almost constant, but in high frequencies the value of the Young's Modulus were decreasing with
increasing frequency. While found the value Young's Modulus remain almost constant, When the skin
layer is separated from the core.
