Photoelastic Stress Analysis

A Plane Polarascope

Plane Pol' © Phil Gee

Anisotropic elastic materials exhibit shear waves when stressed. Certain transparent materials exhibit birefringent properties when stressed

When this child's toy is viewed between crossed polar's ( Dark field ) the locked in stress due to the hot plastic cooling in the injection machine mould can be seen as coloured fringes

© Phil Gee

Models are made of birefringent material and loading applied when viewed between crossed polar's the stress patterns can be seen

© Phil Gee
Crack propagation notch tests


© Phil Gee
A Lifting Eye modeled in Perspex and placed under load in a Polarascope




Work In Progress - I will add more as notes surface from the depths of my 'filing system'

© 1980 - 2008 Phil Gee