Study On Shear Performance Of Novel Demountable Bolted Shear Connectors

With the continuous progress of urbanization in China,environmental problems have become increasingly prominent,and gradually become the focus of attention.Nonetheless,the aging of the population,the labor-intensive traditional construction technology is obviously not in line with the development of society nowadays.Demountable and prefabricated buildings have been proposed for sustainable development of society.Demountable and prefabricated buildings are not lony environment-friendly,but also able to reduce the labor cost and achieve recycling of structural components.Based on the test and ABAQUS software,this paper analyzes the flexural performance of demountable prefabricated steel-concrete composite beams with cone nut and bolt connections,which have novel structural forms.The main contributions and results of this research are summaried as follows:(1)The static push-out test is carried out on the steel-concrete composite beam connected by the conical nut bolt connection,and the push-out test of the conventional bolt connection is set as the control group.The test results show that compared with the ordinary bolt connection,the conical nut bolt connection can greatly improve the ultimate shear capacity of the bolt connection under the condition of minimal ductility loss.(2)The detailed model of push-out test is established.On the premise of verifying the accuracy of the finite element model of push-out test,it is expanded.Based on the more extensive bearing capacity data of the conical nut bolt connection,the shortcomings of the calculation of the conical nut bolt connection by the formula of the national standard are analyzed,and the shear bearing capacity meter applicable to the conical nut bolt connection is proposed.(3)The refined FEA model is established to investigate the flexural behavior of composite beam using the developed novel demountable bolted shear connectors.The parameters include those may affect the flexural performance of demountable prefabricated steel-concrete composite beam were analyzed,and the influence of various parameters on the flexural performance of composite beam is investigated.Summaring the current predict methods for of composite beam flexural stiffness specified in the Chiese desing code,theanalysis results obtained from the detailed FEA model of composite beam are compared to the each method to evaluate its accuracy.In this paper,the theoretical flexural stiffness and bearing capacity of the demountable prefabricated steel-concrete composite beam using novel bolted shear connetors are analyzed.(4)In order to reduce the computing time,a simplified FEA model is proposed to simulate flexural test of the composite beam,by using link-and-spring combination to represent the shear-slip behavior of the novel bolted shear connectors.The feasibility of simplified FEA model is verified by compareing with the detailed FEA model for composite beam.The advantages and disadvantages of the two modeling methods are discussed,the conclusions can contribute to the numerical analysis on the performance of composite beam using the developed novel bolted shear connectors.