Experiment Study On Mechanical Property Of Polyurethane-steel Sandwich Plate System Bridge Deck

Polyurethane-steel sandwich plate system bridge deck is composed of two steel face plates and polyurethane core layer, the elastomer core material and the face plate surface to form a strong adhesive composite structure. Nowadays it is outside the country for the bridge deck, bridge deck replacement and repair of bridge deck reinforcement and other applications. At present, because of the polyurethane-steel sandwich structure applied bridge deck not in the country, and no corresponding design specifications and standards, the paper based on model test, expand mechanical properties of polyurethane-steel sandwich structure bridge deck, to further reveal some characteristics of it, for the application of the polyurethane-steel sandwich structure technology in the country to provide reliable evidence.First of all, the paper determined the size based on some examples of project case, and designed testing program according to the similar model principle, to make experimental investigation. The result, after experimental values compared with the finite element results, shows that the experimenetal data are in agreement with the results of finite element method, and the force law of stiffened sandwich plate which in two different kinds of stiffener spacing are got.Secondly, contrastive finite element analysis were done between the ordinary orthotropic steel bridge deck and the stiffened sandwich plate system bridge deck based on the test model. The results show that the stiffness and bearing capacity of original orthotropic steel bridge decks may improve greatly after strengthening using sandwich structure technology, and the strengthening may effectively reduce the stress level and stress amplitude of the critical position; the out-of-plane bending stress is the main stess of the ordinary orthotropic steel bridge deck, while as to the sandwich structure bridge deck, membranestress is dominant in the stress of its top and bottom face steel plate.Thirdly, contrastive analysis was done among stress curves in the key sections of stiffened sandwich plate finite element models, that in three different kinds of stiffener spacing and utilized the same boundary conditions and same loads. Moreover, the paper made comparative analysis among the maximum deflection and stress value of all the finite element models built above. The results show that, transverse stress is the main control stress of ordinary orthotropic steel bridge deck, while as to the sandwich structure bridge deck, longitudinal maximum stress and transverse maximum stress have only a little difference; The elastomer of sandwich structure bridge deck provides continuous supported so that deflection, maximum stress is significantly reduced, eliminating the need of closely spaced discrete stiffeners, may greatly reduce the stiffener number; from the load location section to the mid-span sections,some variation laws of pressure peak stress and tension peak stress on outside surface of sandwich plate models ,which in three different kinds of stiffener spacing, are got.Finally, the paper discussed mechanical property changes of polyurethane-steel sandwich structure bridge deck with the core layer thickness variation, as the increase of the core layer thickness, comparative analysis on the outside surface stess of key section , which in the three ribs sandwich plate model ,were probed. The order of stress propertie sensitivity on the core layer thickness parameter variation was got.In short, researches, which are about mechanical property analysis and structure design of polyurethane-steel sandwich plate system bridge deck, will have a important reference value to the construction of the steel bridge deck system in our country.