Document Type

Thesis

Date of Award

1-31-1986

Degree Name

Master of Science in Mechanical Engineering - (M.S.)

Department

Mechanical Engineering

First Advisor

Sachio Nakamura

Second Advisor

Bernard Koplik

Third Advisor

Benedict C. Sun

Abstract

Bone differs from most engineering materials in the composition of its structure. The classical theory of elasticity fails to correctly predict the stress concentration effects in bones with precracked or notched surfaces, and can be applied only to those materials which exhibit more homogeneity and isotropicity than bone. Therefore, generalized continuum theories, which have addditional degrees of freedom, must be used to determine the stress concentration effects in human bone, especially in regions of high strain gradient, such as a hole or an interface.

In this thesis, efforts have been made to identify the material constants of human bone since there is no generally agreed value for the Young's modulus of bone. In order to simulate the experimental results of Lakes and Yang, a finite element model of a section of human bone is developed and analysed. The identified micropolar elastic constants are used in the preparation of the input data to run the computer program on micropolar elasticity. A curve of strain ratios v/s the distance/hole radius ratios is then drawn and compared with the experimental curve obtained by Lakes and Yang.

The comparison of the two graphs indicates that there is a lot of consistency between the two curves. Therefore, the micropolar elastic constants proposed in this thesis can be considered as fairly good approximations of the exact values which are presently unknown.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.