Research And Development Of Hollow Sandwich Plate System For Bridge Deck

SPS(Sandwich Plate System)deck is a new type of composite structural which has been widely used in marine and civil engineering in recent years,the application in bridge engineering is in ascendant.HSPS(hollow SPS)deck is an improved form of SPS deck,which has higher carrying efficiency and economy,and has wide prospect in the application of bridge deck.Research on HSPS deck is still in the initial stage at home and abroad.The relevant research literature is less,the further research and application on HSPS deck is a new field with lots of unsolved issues.In this thesis,the key manufacturing process,reasonable cross-section form,simplified analysis method and static mechanical properties of HSPS deck are studied based on the experimental results,theoretical analysis and numerical simulation technology,which can be used as a reference for the theoretical,experimental research,manufacture and design of HSPS deck.In this paper,the key manufacturing process of SPS deck is studied,and the surface treatment process of steel plate is optimized.The experiment results show that the adhesive Chemlok-218 coating on the surface of steel plate after blast cleaning,can significantly increase the tensile lap-shear strength between polyurethane elastomer and steel.So as to ensure the use of SPS deck in reliable bonding,and further improve the carrying capacity.Then,the reasonable cross-section form of HSPS deck is analyzed theoretically,and the conceptual scheme of HSPS deck section is given.Through the analysis and comparison of the conceptual schemes,indicating that the vertical circular hollow scheme holds higher transverse bending stiffness and bucking stability,and the stress of the core layer is more reasonable among the schemes without core tubes.The insertion of steel core tube can significantly improve the longitudinal and transverse bending stiffness of the HSPS deck.Under the premise that the weight of the structure and the cost of the raw material are similar,the improvement of the structural stiffness of the square tube is more obvious than that of the circular tube.Thirdly,the simplified method for HSPS deck is discussed.The homogenization method based on strain energy equivalence is applied to the prediction of equivalent elastic constants of HSPS deck for the first time,and the equivalent elastic constants have higher accuracy in solving both static and dynamic problems.A simplified algorithm based on the combination of material mechanics analysis and Radial Basis Function(RBF)neural network is proposed for the problem of cumbersome operation in the actual use of the homogenization method based on strain energy.On this basis,the calculation method of the stiffness problem of HSPS deck is derived based on the classical laminates theory.Finally,based on the numerical simulation technology,and combined with a specific example,the static mechanical properties of two kinds of bridge deck system(HSPS deck and orthotropic steel deck(OSD))are compared and analyzed.Because of the simplicity of the structure and the reduction of the number of weld seams,the HSPS deck can not only improve the construction efficiency,but also can effectively solve the fatigue problem of OSD bridge deck system.The calculation results show that the stress of material is concentrated at the intersection of longitudinal,transverse beam and HSPS deck,while the local reinforcement measures can help to improve the stress concentration of the HSPS deck at the supports of longitudinal and transverse beam.According to the analysis of the parameters of the section size of the HSPS deck,it is found that the maximum tensile stress of the top plate is significantly influenced by the height of the core layer and the volume reduction rate,while the effect of the maximum compressive stress of the bottom plate on the two parameters is weak.