In this study, an inclusion in the rotating disc and the interference problem of the crack were examined. The influence of the mechanical property of the inclusion and the distance to the crack tip was examined. The stress intensity factor was determined by using photoelasticity and the method of caustics. As a result, the stress intensity factor was decreased when Young's modulus of inclusion increased. Moreover, the stress intensity factor decreased as the distance from the crack tip to the inclusion boundary became longer. The stress intensity factor of the crack on the rotation center side increased more than the cracks on the circumference side of the inclusion.
An universal joint is an important mechanism in the machine structures such as vehicles and ships for the transmission parts of the rotation machine device. The cause of the loss in the machine structure originates in the stress concentration, and is seen in various examples of the accident. The numerical analysis by way of the finite element method is a mainstream according to the advancement of the computer for the strength analysis of this adjustable joint. However, it is current that the report of the experiment analysis is few for the cost reduction. It experimented on this research applying three dimensional intersection axis angle to reproduce the vicinity of actual condition. An effective stress freezing method to a complex three dimensional stress analysis in the experiment was adopted and it made comparative study of the photoelasticity experiment about the state of the stress when the intersection axis angle was changed the line.
Loosening of the wheel bolts may be the cause of accidents where the wheel falls off while the trailer is running. When the transverse force exceeds a certain proportion of the bolt shaft force, the wheel nut begins to loosen. On the other hand, it is clear by the numerical analysis that the transverse force as it self is influenced by the condition of bolt fastening. In this report, more suitable transverse force is searched by thinking out the method of bolt fastening.