S0302-2-5 Residual Stress Measurement of Light Bulb for Automobile by Sensitive Photoelasticity

Abstract

Photoelasticity of high sensitivity is applied to measure the residual stress of the pincher portion of the light bulbs for automobiles. The residual stress is not so high that isochromatic fringes don't appear, but there only exists the change of brightness. The residual stress of the pincher portion is obtained by measuring the light intensity with a light detector of high sensitivity. The results measured by the method of the present study are compared with that measured by the phase-shifting photoelasticity. The comparison says that the method of the present study is useful to measure the residual stress of light bulbs for automobiles.