In this research, a robust and reliable compression testing technique ("two-camera two-mirror" technique) for anisotropic, heterogeneous, and porous materials is developed for both nondestructive uniaxial loading in different orthogonal directions and destructive uniaxial loading over the yield point. The whole specimen strain can be measured using the video extensometer technique that provides a prompt evaluation method for strain measurement; and the full-field three-dimensional (3D) surface strain can be measured using the digital image correlation (DIC) technique that provides abundant information about the mechanical properties. In addition, the volumetric strain can be measured from micro-computed tomography (μCT) scans before and after the testing. Possible errors of this compression testing technique are calibrated. This technique was also validated using a variety of biological materials and biomaterials, such as birch wood blocks, solid rigid polyurethane (PU) foams, open-cell aluminum foams, and customized Ti-6Al-4V ELI lattice structures.
Several trabecular bone specimens from porcine cervical spines are tested nondestructively or destructively using the experimental technique. Elastic and post-yield behaviors of trabecular bone specimens are measured. Besides the nominal stress-strain curve, more mechanical properties of these specimens such as Poisson’s ratio and the local strain mapping are obtained. The 3D full-field measurements based on μCT data from one of the specimens are demonstrated as well.
A variety of micro-finite element (μFE) modeling meshes and tissue material models are investigated using ANSYS. An elasto-plastic μFE model of trabecular bone based on μCT reconstruction is validated and verified. The tissue material model of trabecular bone is predicted using the method of fitting the experimental nominal stress-strain curve. More measurements could be performed from μFE model, and a few examples are demonstrated.
|Commitee:||Dechow, Paul C., El Shamy, Usama, Kovacevic, Radovan, You, Jeong Ho|
|School:||Southern Methodist University|
|School Location:||United States -- Texas|
|Source:||DAI-B 73/01, Dissertation Abstracts International|
|Subjects:||Biomedical engineering, Mechanical engineering, Biomechanics|
|Keywords:||Compression testing, Image correlation, Micro-computed tomography, Strain measurements, Trabecular bone|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be