Three dimensional effective properties of composite materials for finite element applications

A model has been developed to compute the effective properties for an arbitrarily shaped element with multiple anisotropic material regions. The analysis utilizes a finite element technique to resolve the complexity of three-dimensional layer geometry, anisotropy, ply orientations, and multi-material regions within an element. Accordingly, the model accounts for complex geometries requiring changes in mesh density and/or arbitrarily shaped elements that cannot be readily aligned with the layers of the laminate. Discontinuity due to ply drop-off or layer terminations within an element is also considered. The computed elastic constants are accurate, especially for the transverse shear properties. The analysis is particularly suitable for finite element applications of near-net shaped thick-section structures. A preprocessor was developed incorporating the effective property model to allow for generation of finite element representations for computer codes such as DYNA3D and ABAQUS.