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Innovative design of composite structures: Axisymmetric deformations of unsymmetrically laminated cylinders loaded in axial compressionThe study focuses on the axisymmetric deformation response of unsymmetrically laminate cylinders loaded in axial compression by known loads. A geometrically nonlinear analysis is used. Though buckling is not studied, the deformations can be considered to be the prebuckling response. Attention is directed at three 16 layer laminates: a (90 sub 8/0 sub 8) sub T; a (0 sub 8/90 sub 8) sub T and a (0/90) sub 4s. The symmetric laminate is used as a basis for comparison, while the two unsymmetric laminates were chosen because they have equal but opposite bending-stretching effects. Particular attention is given to the influence of the thermally-induced preloading deformations that accompany the cool-down of any unsymmetric laminate from the consolidation temperature. Simple support and clamped boundary conditions are considered. It is concluded that: (1) The radial deformations of an unsymmetric laminate are significantly larger than the radial deformations of a symmetric laminate, although for both symmetric and unsymmetric laminates the large deformations are confined to a boundary layer near the ends of the cylinder; (2) For this nonlinear problem the length of the boundary layer is a function of the applied load; (3) The sign of the radial deformations near the supported end of the cylinder depends strongly on the sense (sign) of the laminate asymmetry; (4) For unsymmetric laminates, ignoring the thermally-induced preloading deformations that accompany cool-down results in load-induced deformations that are under predicted; and (5) The support conditions strongly influence the response but the influence of the sense of asymmetry and the influence of the thermally-induced preloading deformations are independent of the support conditions.
Document ID
19900016048
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Hyer, M. W. (Virginia Polytechnic Inst. and State Univ. Blacksburg, VA, United States)
Paraska, P. J. (Virginia Polytechnic Inst. and State Univ. Blacksburg, VA, United States)
Date Acquired
September 6, 2013
Publication Date
June 1, 1990
Subject Category
Structural Mechanics
Report/Patent Number
NAS 1.26:186635
NASA-CR-186635
VPI-E-90-10
Accession Number
90N25364
Funding Number(s)
CONTRACT_GRANT: NAG1-665
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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