Accession Number : ADA302712

Title :   Boundary Layer Thermal Stresses in Angle-Ply Composite Laminates. Part 1.

Descriptive Note : Final rept.,

Corporate Author : ILLINOIS UNIV AT URBANA

Personal Author(s) : Wang, S. S. ; Choi, I.

PDF Url : ADA302712

Report Date : FEB 1981

Pagination or Media Count : 66

Abstract : Thermal boundary-layer stresses (near free edges) and displacements are determined by a unique method developed under this grant. This method consists of an eigenfunction expansion technique and the establishment of an appropriate particular solution. Current solutions in the region away from the singular domain (free edge) are found to be excellent agreement with existing approximate numerical results. As the edge is approached, the singular term controls the near field behavior of the boundary layer. Results are presented for cases of various angle-ply graphite/epoxy laminates with (e/-e/-e/9) configurations rough-the-thickness) stresses. Thermal boundary-layer thicknesses of different composite systems are determined by examining the strain energy density distribution in composites. It is shown that the boundary-layer thickness depends on the degree of anisotropy of each individual lamina, thermomechanical properties of each ply, and the relative thickness of adjacent layers. Also, the interlaminar thermal stresses are compressive with increasing temperature. The corresponding residual stresses are tensile and may enhance interply delaminations. (MM)

Descriptors :   *LAMINATES, *THERMAL STRESSES, THERMOMECHANICS, COMPOSITE MATERIALS, DISPLACEMENT, BOUNDARY LAYER, EIGENVALUES, THERMAL EXPANSION, ANISOTROPY, BOUNDARY VALUE PROBLEMS, RESIDUAL STRESS.

Subject Categories : Laminates and Composite Materials
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE