リベット穴の縁クラックに対する応力拡大係数

抄録

The stress intensity factors for the edge crack of a rivet hole in the rivet joint are evaluated by means of photoelasticity. In the ordinary design of rivet joint, the friction between the plates produced by fastening the rivet and the effect upon the plates by the bending deformation of the rivet are neglected. From this standpoint, the photoelastic experiment is carried out using the band plate models with a rivet hole loaded by tension.
The breaking test by acrylic acid resin model is conducted to examine the direction of crack throughout the section of the plate when the breaking occurred. The epoxy resin models are prepared for various form factors; crack depth, crack angle and the distance from the center of rivet hole to plate edge. The isochromatic fringe patterns around the crack tips obtained by the CCD camera are transformed to the thinning image by utilizing the image processing, thus the stress intensity factors are estimated by means of personal computer using the program based on the over-deterministic method. The stress intensity factors obtained are summarized in the diagrams shown as the behavior depending on the form factors.
Moreover, the breaking test using the steel models of rivet joint with three rivet holes in a row is carried out to examine the position of the broken hole. The results are compared with those already obtained photoelastically by authors.