Study On Interface Anti-slip Performance Of Riffled Steel Plate-STC Composite Structure

At present,most of the steel bridges appeared different degrees of disease and many urgent problems during construction and operation,the orthotropic steel bridge deck is prone to steel structure fatigue and damage of pavement,which seriously influence its usability and durability.Therefore,the team which author is in have developed the light-weight steel-STC(Super Toughness Concrete)composite bridge girder can significantly improve the stiffness of the bridge deck,so as to substantially prohibit the bridge deck pavement from high stress working environment,extend the service life of paving layer,fundamentally solve the problem of paving layer is easy to damage;The STC layer with orthotropic steel plates can significantly reduce the stress amplitude of fatigue details while under wheel loads and improves the local and overall mechanical properties of the structure.At present,the use of stud in application of light-weight steel-STC composite bridge girder is basically used between 150-200mm,The stud arrangement is very dense,Cause the stud number a lot at the whole bridge,affecting the bridge cost,time and stress performance of plate at welding position.This article uses the Riffled Steel Plate instead of common steel plate used in the bridge deck,using the bonding and embedding effect of the pattern and STC layer,improving the anti-slip performance of the interface,designed the riffled steel plate-STC combination structure static push-out test and four-point bending test,and through the finite element analysis method to complete the following work:(1)In order to obtain the shear rigidity of stud in riffled steel plate-STC composite structure,three push-out test pieces were designed and two kinds of cases with or without interface bonding were considered,the results show that the push-out specimens of initial obvious slip load is larger.The bonding force of the composite structure interface and the embedding force between the pattern and STC layer are strong;the characteristic slip value of the specimen is less than 6mm,the short stud in the steel-STC composite structure does not belong to ductility shear connectors;The ultimate bearing capacity of specimen is greatly improved than ordinary plate specimen,increases about 24.4%;The above data show that the shear rigidity of the studs in riffled steel plate-STC composite structure has better performance than ordinary steel plate-STC composite structures,shear stiffness of tie nails in the riffled steel plate-STC composite structure is large,the shear rigidity of the studs is 2.4-3.3 times of that of the ordinary steel plate specimen,the composite structure can better cooperate and make the advantages of the composite structure;under the same load,the actual stress of studs in riffled steel plate-STC composite specimen is less than the ordinary steel plate specimen,and we can increase the stud spacing to achieved optimization design of stud.(2)In order to obtain the flexural performance of riffled steel plate-STC composite structure and the difference with the ordinary steel plate-STC composite structure,16 composite specimens were designed,considering the reinforcement ratio,interfacial bonding form,stud arrangement spacing total of three kinds of variables.The results show that:for the stud different number of specimens,the number of studs greatly influence the bearing capacity of the structure,the load capacity of multi-stud specimen is greater than the less stud specimen,in the elastic phase less stud riffled steel plate specimen and multi-stud ordinary steel plate test pieces almost equal in overall stiffness,the load-deflection curves are consistent,the load-slip curves are also consistent,shows that less stud riffled steel plate composite structure has similar mechanical properties with multi-stud ordinary steel plate specimen in elastic stage,whether oiling the interface of composite structure only affects the mechanical properties of the specimen with less stud,specimen with oil at interface has bigger deflection and larger slip under the same load,but there is no obvious effect on the multi-stud specimen,which indicates that the number of stud is more,the steel plate and STC layer can and the composite plate specimen is more consistent with the flat section assumption.The STC layer and the steel structure can better cooperate bearing;the reinforcement ratio affects the structure's stress performance,the dense reinforcement specimen bearing capacity is higher,the overall ductility is better,the cracking stress is higher,which indicates that the dense reinforcement can improve the force performance of the composite structure.(3)Use Goodman flexible interlayer assumptions and elastic body deformation theory and the principle of minimum potential energy,we can get differential equation of deflection and slip of simply supported composite beams.Then derive the formula of simply supported composite beams under symmetry concentrated loads,Compared with the test value and the finite element software analysis results,the results show that the analytic expression of the deflection is reasonable and can reasonable simulate considering the interface slip of the stud on the influence of the composite structure.(4)Use finite element analysis software to analyze riffled steel plate which may used to the steel box girder of Huzhou Wuyi Bridge.The steel box girder with 300mm distance of stud and riffled steel plate instead of ordinary steel plate used in light-weight composite bridge structure,the maximum shear stress amplitude of the stud is equivalent to the previous plan,the distance of stud can be set from 200mm to 300mm,reduce the amount of stud to improve the steel-STC light combination of deck structure applications economy.