Research On Optimal Design Of Structural Parameters And Fatigue Property Of Rib-to-deck Welded Joint In Orthotropic Steel Deck

With the rapid development and wide application of orthotropic steel deck,its superiority has become increasingly prominent.More and more bridge construction has adopted this kind of structure,but its fatigue cracking has been a technical problem that has long plagued the engineering circle.In this paper,aiming at the fatigue problem of orthotropic steel deck,the path to improve its fatigue performance is explored in two ways:On the one hand,calculating by using the large-scale general FEM software ABAQUS at the premise of meeting the current codes' requirements on stress,deformation and detailing,the structural parameters of orthotropic steel deck are optimized,and a set of reasonable matching values of U-rib's size and distance,diaphragm's height and distance are suggested when the thickness of deck is changed from 16 mm to 32 mm in the sequence of even,to improve its performance of working harmoniously as a whole and ensure the rationality and economy of bridge design.At the same time,reducing the number of U-ribs and diaphragms during manufacture,thereby decreasing the welding work of the whole bridge,reducing the probability of fatigue failure,and improving its fatigue durability is hoped to be achieved.On the other hand,in reference to a bridge's butt joint between the decks with unequal thickness and the U-ribs with unequal height,designing the full-scale specimen which is double-side welded between the rib and deck,carrying on static load and fatigue test whose test dates are compared with theoretical calculation and ABAQUS calculation results,the static behavior and fatigue performance of rib-to-deck double-side welded joint which has been a realized technology are studied.The starting position and propagation law of the fatigue crack are summarized.Besides,the fatigue strength is assessed by the hot spot stress method.Finally,comparing with the fatigue performance of rib-to-deck single-side welded joint,the significance of the double-side welded joint for improving orthotropic steel deck's fatigue durability is pointed out.