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Title: A study of woven fabric-reinforced composite materials using an invariant-based orthotropic plasticity formulation

Miscellaneous ·
OSTI ID:6069475

This dissertation presents an investigation of the mechanical behavior of woven fabric-reinforced composite materials. Linear and nonlinear material behavior of a woven fabric-reinforced composite was modeled using a three-dimensional finite element computer program. Tension and shear load case were investigated using a minimechanics unit cell and results from the finite element analysis were compared to experimental data. The three-dimensional finite element computer program was developed based on an existing computer program known as WYO3D initially developed by the Composite Materials Research Group at the University of Wyoming. This computer program was modified in order to conduct a nonlinear finite element analysis for either material nonlinearities and/or nonlinear behavior due to material damage. To perform the analysis a constitutive relation was needed which accurately predicted the nonlinear behavior for a wide range of orthotropic composite materials. Work presented here develops an invariant-based flow rule which was able to predict plastic behavior of orthotropic materials without the use of an effective stress-effective strain relation. This orthotropic plasticity formulation represents a major contribution to the analysis of composite materials over previously used theories. The finite element formulation for the invariant-based flow rule has also been presented. A finite element formulation was developed and implemented which was able to predict material damage occurring within the composite material.

Research Organization:
Wyoming Univ., Laramie, WY (USA)
OSTI ID:
6069475
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English