An analysis of interlaminar stresses in unsymmetrically laminated plates. Interim Report No. 81

Technical Report · Thu Nov 01 04:00:00 EST 1990

OSTI ID:6360031

Norwood, D S; Shuart, M J; Herakovich, C T

The results of a numerical study of the interlaminar stress fields within unsymmetrically laminated anisotropic plates is presented. The focus of the study is upon the linear thermoelastic response of thin square laminated composite plates subjected to extensional, compressive, or thermal loading. Symmetric and unsymmetric 0/90, +45/-45, and 0/+45 laminate stacking sequences are examined to determine the effects of mismatch between adjacent layers in Poisson's ratio, coefficient of mutual influence, and coefficients of thermal expansion. Since the out-of-plane (transverse) deflections of unsymmetric laminates are typically large, a geometrically nonlinear kinematic description is used to account for the large displacements and large rotations. The geometrically nonlinear three dimensional boundary value problems are formulated from nonlinear elasticity theory and approximate solutions are determined using the finite element method. A total Lagrangian, displacement-based, incremental finite element formulation is implemented using Newton's method. Geometrically nonlinear global/local finite element analysis is used to obtain improved free edge stress predictions. The conclusions apply to extensional, compressive (prior to a change in mode shape), and thermal loading.

• Research Organization: Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (USA)
• OSTI ID: 6360031
• Report Number(s): N-91-14424; NASA-CR--187657; NAS--1.26:187657; CCMS--90-11; VPI-E--90-18; CNN: NAG1-343
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
BOUNDARY-VALUE PROBLEMS
COMPOSITE MATERIALS
COMPRESSIBILITY
ELASTICITY
EXPANSION
FINITE ELEMENT METHOD
LAYERS
MATERIALS
MECHANICAL PROPERTIES
MECHANICAL VIBRATIONS
NUMERICAL SOLUTION
PLATES
POISSON RATIO
STRESS ANALYSIS
TENSILE PROPERTIES
THERMAL EXPANSION
THERMOELASTICITY