Abstract

Through the use of generalized spherical harmonic basis functions a spectral representation is used to model the microstructure of cubic materials. This model is then used to predict the macroscopic elastic and plastic properties of materials with cubic crystal symmetry and various sample symmetry including triclinic and axial—symmetric. Building on the work of citeN{Barnett-FractureMechanics} the influence that anisotropy has on the fatigue response of the material is also modeled. This is accomplished through using the effective elastic stiffness tensor in the computation of crack extension force G. The resulting material model and macroscopic property calculations are the foundation for a software package which provides an interface to the microstructure. The Microstructure Sensitive Design interface (MDSi) enables interaction with the material design process and provides tools needed to incorporate material parameters with traditional design, optimization, and analysis software. Therefore the microstructure model can be optimized concurrently with a geometric model to further increase the overall design space. The software is then be used to explore how changes in the microstructure affect the performance of a turbine disc. The additional design space afforded by inclusion of the material parameters show that the total mass of the disk can be lowered by 9.5%. Additionally when the same geometry and loading conditions are considered and only the texture of the material is modified G is reduced be more than an order of magnitude.

Degree

College and Department

Ira A. Fulton College of Engineering and Technology; Mechanical Engineering

Rights

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