Validation of Vierendeel Mechanism in Shear Tests of Cold-Formed Steel Channel Sections with Web Holes

For hot-rolled steel structures with sufficiently large web openings, it is well recognized that local Vierendeel bending moments develop at the four corners of the openings, which subsequently result in the formation of plastic hinges. This mechanism has recently been observed in finite element simulation of shear tests of cold-formed steel structures with substantial web holes. This paper experimentally verifies the existence of the local Vierendeel bending moments by strain measurements at the cross-sections next to the corners of the holes in cold-formed steel shear tests. The measurements are obtained by strain gauges as well as by Digital Image Correlation (DIC) method which is based on the processing of series of images taken from the tests. The agreement between the measured strain and the strain computed using DIC is also presented.