Accession Number:

ADA555770

Title:

Simulating the Mechanical Response of Titanium Alloys Through the Crystal Plasticity Finite Element Analysis of Image-Based Synthetic Microstructures

Descriptive Note:

Master's thesis

Corporate Author:

OHIO STATE UNIV COLUMBUS

Personal Author(s):

Report Date:

2012-01-01

Pagination or Media Count:

103.0

Abstract:

Micromechanical crystal plasticity finite element simulations of the response of synthetic titanium microstructures are carried out with the goal of quantifying the effect of microstructure on mechanical properties. Two separate materials are studied 1 an alpha-Beta Ti-6Al-4V material and 2 a highly-textured, rolled lpha Ti-3Al-2.5V sheet material. Performing accurate finite element analyses begins with accurate image-based characterization of the morphological and crystallographic features of the materials at the microstructural scale. Then, statistically equivalent representative 3D microstructures are built and meshes are generated for crystal plasticity based finite element method CPFEM analysis. For the Ti-3Al-2.5V material, experimental results from the displacement controlled mechanical testing of dog bone shaped, rolled specimens are used for the calibration of elastic parameters as well as anisotropic crystal plasticity parameters. The inspection of micrographs of the rolled material showed elongated grain shapes which led to the updating of the crystal plasticity model to include grain aspect ratio dependence on the Hall-Petch size effect an update of a previous size effect model which assumed spherical grains. Model validation is achieved by comparing load controlled experimental results with simulated creep results. For the Ti-6Al-4V material, the robust and validated analysis tool is used to perform sensitivity analyses and a quantitative understanding of how individual microstructural parameters affect the mechanical response properties of the alloy is developed. Functional dependencies are proposed that directly connect the metals microstructural features to creep response, yield strength response, and tensile response.

Subject Categories:

  • Properties of Metals and Alloys
  • Crystallography
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE