Polarized Light Stress Investigations on Tensile Bar with Holes and on a Rivet Hole

摘要

The development of stress conditions in a tensile bar with holes was determined by photoelastic experiment from the theoretically tractable case of infinitely small drilled holes with increasing hole diameter. The changes caused by the appearance of new singularities observed with large holes were specifically determined. Isoclinics were computed for the infinite sheet and recorded without error for finite relationships. The most important practical result is represented by the curve of stress increase at the smallest cross section as a function of hole diameter, for which a simple approximate formula is given applicable to case of the hole diameter being less than one half the width of the bar. At the rivet hole there is a uniform stress condition dependent upon the Poisson constant m. The calcution of the isoclinics and of the hill of shear stress for this condition, while disregarding the edge of the bar, proves that the changes related to extreme limiting values of m are negligible and thus indicates that photoelastic methods may be utilized even in these exceptional cases.