Stress concentration of circular and elliptic holes in the web of beams with wide-flange sections

Abstract

Long span beams with wide-flange in w shapes section commonly appeared to support deck in various ships. Many holes in web of the beam were punched into a few shapes because it was necessary for wires through them in the process of building of ship. Basically, shapes of holes were circular and elliptic and positions were in mid-span or near to two ends. Stress concentration of holes had to take into account in the design and reasonable measurements enhanced strength around the holes had to be properly applied. A new mixed geometric similarity theory was applied to produce many types of models of long-span beam with holes in web, in which dimension ratio varied with different parts of beam in order to avoid a part of model beam was too thin. Many models of beam were made from a new photoelastic materials with low freezing temperature (50°C~70°C). Different types of Loading and constraints were simulated. Thus, isochromatic fringe patterns were obtained in circularly polarized light field. Factor of stress concentration were calculated and conclusion were drawn through fringe patterns. Methods were acquired to enhance strength of beam and reduce stress concentration.