Experimental investigations on combined resistance of corrugated sheets with strengthened cross-sections under bending and concentrated load

Abstract

Multi-span corrugated sheets have lower resistance from single-span beams. This effect results from the combined bending moment and bearing load acting at the internal supports. It is a possibility to increase the resistance by means of local strengthening of critical cross-sections over the internal supports. The strengthening can be achieved by doubling of cross-sections (lap connection, applying an additional corrugated sheet). At present there is a lack of knowledge about the resistance of doubled cross-sections of corrugated sheets under concentrated load, bending moment or combined concentrated load and bending moment acting at the strengthened cross-section. The results of experimental investigations on combined M–F relationship for corrugated sheets with doubled cross-section have been presented. For 35 tested models the following parameters have been changed: the length of strengthening a, span distance l, the way of a profile placement, the structure of strengthening, the number and placement of connectors. Obtained results have been compared with those received experimentally for unstrengthened models [Biegus A, Czepiżak D. Research on the interactive resistance of corrugated sheets under combined bending and contact pressure, Thin-Walled Struct 2006;44:825–831]. The conclusions leading to the optimal parameters of strengthening of corrugated sheets have been given.