Numerical Analysis Of Shear Capacities Of Reinforced Concrete Beams Strengthened By Direct-shear-bolted Steel Plates

In the field of reinforcement engineering,some relatively mature reinforcement technologies have been developed at domestic and overseas.However,it’s different for some reinforcement methods to use due to the limitations of structure function and working environment.Even there are some problems at reinforcement methods.Therefore it is necessary to improve reinforcement methods in order to adapt to the complex and changeable engineering reinforcement problems.On the basis of summarizing the characteristics of the existing strengthening system,this research group developed a set of strengthening technology which can effectively enhance the performance of RC beam--direct-shear-bolted steel plate strengthening technology.The special structure of the direct shear anchor bolts can effectively eliminate the installation gap between the anchor bolt and the hole wall of the steel plate,thus the compatibility of anchor group is secured to the extreme extent.It will make the best of the material properties of the steel plates and the anchor bolts.At present,there are many researches on flexural strengthening of RC beam in the field of bolted steel plate,but the researches on shear performance of the bolted-side steel plate are still lacking especially the researches on the direct-shear-bolted steel plate strengthening method which as a new method.Three set of shear capacities experiment of RC beam strengthened by directshear-bolted was conducted,with the shear span ratio of beam as variables.The experiment results is used for analyse strengthening mechanism of the method and discusses the influence of shear span ratio on shear capacities.In this paper,the model verification and parameters analysis were carried out with the help of the finite element analysis software ABAQUS on the basis of the test results,and some conclusions are given for analysis in order to instruct practical engineering application.The main research contents and conclusions of this paper are as follows:(1)Based on the previous experiment results of beam’s shear capacities,the strengthening beam members were modeled under each variable using the ABAQUS finite element analysis software,and the simulation results were verified one by one.The results show that the finite element model of strengthening beams established by the modeling method in this paper can simulate the load-deflection curve and deformation characteristics of members at load more realistically.(2)Based on the verification of finite element model,the parameters of RC beam strengthened by direct-shear-bolted steel plate were analyzed,and the influences of concrete strength,horizontal distance between bolts,steel plate height,number of bolts and thickness of steel plate on shear capacity of RC beam members were explored.The results show that the initial stiffness of the strengthening beams is mainly affected by the properties of the members themselves,and barely depends on the steel plates.The shear span ratio,the strength of concrete and the height of the steel plate have more significant effects on the shear capacity,followed by the distance between bolts,and the thickness of the steel plate has little effect on the shear capacity.