Samuel Haughton Lecture 2002

17/09/2002 in Sligo Park Hotel, Sligo

Images from Waves – photoelastic modelling of bones

John F. Orr, PhD, School of Mechanical and Manufacturing Engineering, Queen’s University, Belfast, Northern Ireland

Abstract:

Background: This paper cites the development of the principles of photoelastic stress analysis, contemporary to the life of Samuel Haughton. Subsequent studies of bone and joint replacements are discussed, with reference to hypotheses regarding bone, including the coincidence of trabecular structure with principal stresses. Issues regarding assumptions of homogeneous and isotropic properties in photoelastic modelling are acknowledged.

Aim: Awareness of photoelastic methods is often through the visual appeal of the coloured fringe patterns. The aim of this paper is to complement this awareness by demonstration of the quantitative analyses that may be conducted through biomechanical examples.

Methods: Examples of new pseudo three-dimensional model analyses are presented together with a method for photoelastic study of cancellous bone, which entails novel procedures for preparation of replicate models and for optical evaluation of fringes.

Conclusion : Photelastic analysis offers novel solutions to studies in biomechanics, which are facilitated by contemporary modelling materials.

 

Introduction:

It is a great honour to have been invited to prepare the 8th lecture in commemoration of Samuel Haughton, an opportunity that also brings the responsibility of choosing a topic to acknowledge his contributions to science. The range of the latter have been responsible for him being notably portrayed as a polymath — ‘a person of wide-ranging knowledge or learning. Thus, it is hardly surprising to find the science of polarised light addressed among Samuel Haughton’s complement of some 268 papers.

Images from Waves — photoelastic modelling of bones

This being the eight presentation of the Samuel Haughton Lecture since its beginnings in 1995.

Meeting chaired by Brendan McCormack

Bronze Medal Winner: John Hession