A simple method of obtaining ``exact`` values of the natural frequencies of vibration for some composite laminated structures for civil construction

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:143200

Kim, D H ^[1]

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1. Korea Composites, Seoul (Korea, Republic of)

The author has proposed to use the quasi-isotropic constants by Tsai for the preliminary design of the composite primary structures for the civil construction. Such structures generally require a large number of laminae layers. This concept greatly simplifies the calculation effort at the early stage of design. Simple equations which can predict ``exact`` values of the natural frequencies of vibration for the special orthotropic laminates are presented. Many laminates with certain orientations have decreasing values of B{sub 16} and B26 as the number of plies increases. Such laminates, with D{sub 16}=D{sub 26}{yields}0, including the laminates with anti-symmetric configurations can be solved by the same equation for the special orthotropic laminates. If the quasi-isotropic constants are used, the equations for the isotropic plates can be used. Use of some coefficients can produce ``exact`` values for laminates with such configuration. The most of the structures for civil construction require many layers of plies even though the ratio of the thickness to the length is small so that the effect of transverse shear deformation can be neglected. The study result on a couple of laminate configurations was reported by the Textile Composites in Building Construction 92, in Lyon, France in June, 1992. The present paper reports the result of the further extension of the previous study.

• OSTI ID: 143200
• Report Number(s): CONF-930246--; ISBN 0-87339-251-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
COMPOSITE MATERIALS
DEFORMATION
MATHEMATICAL MODELS
MECHANICAL VIBRATIONS