The effect of hole size and position in circular plates

A study has been carried out to investigate the effect of hole size and position on the bending strength and stiffness of circular plates subjected to pressure loading. This has involved developing theory for validating basic finite element analyses for similar annular plates and then extending models for dealing with eccentric hole arrangements. This paper summarises equations which have been derived specifically for circular plates (or diaphragms) containing a central hole when firmly held around the outer perimeter and supporting a uniformly distributed (pressure) load. It presents the resulting hoop and radial stress distributions which are obtained for a range of different hole sizes and compares these with those obtained using finite element analysis. Although the results compare very well for most geometries considered (especially at the no hole / small hole transition), there are other geometries where results do not compare favourably. As this characteristic has been found with other component shapes studied, the paper questions whether well established analytical data is generally as precise as previously assumed before the advent of finite element solutions. In addition, the desirability for initially validating the results from simple finite element models with reliable results is advocated.