Mesomechanics Simulated Method On The Pseudo-Constitutive Behaviors Of Perfobond RIB Shear Connectors

Nonlinear finite element simulation is combined with the existing test results to study the mechanical characteristics of perfobond rib shear connectors which are subjected to the combined tension and shear stresses. Based on the foregoing research results about FEA (finite element analysis) and the cell model in mesomechanics, a new FEA method is put forward. Such FEA method is distinguished by its high computation efficiency as well as the satisfactory accuracy that meets the needs of engineering design.The present work includes:(1) The development and the load transfer mechanism of current composite bridges and shear connectors are analyzed and summarized in detail.(2) Based on the cell model which is traditionally used in the research of the constitutive behaviors of composite materials, a new type of mechanical mdel of perfobond rib shear connectors is proposed. The perfobond rib shear connectors and adjacent structure in a certain zone are replaced by the homogeneous equivalent material according to the principle that the load-slip relation of new structure should be equivalent to the original one. In this way, the complex structure of shear connectors can be simplified in the mechanical model. Thus the FEA process can be much more efficient.(3) The nonlinear FEA model of perfobond rib shear connectors has been set up. Following efforts are paid with the comparison between the existing test results and the calculation results, as well as the parameter analysis:Ⅰ. To fit the boundary conditions of displacement, assume a displacement field of the cell model. Then use the perturbation method and construct a cell displacement field which contains undetermined parameters by series, to make the border value zero.At last sum zhe two cell displacement fields above.Ⅱ. According to the constitutive relation of equivalent material of a cell, calculate the cell stress field and strain energy by the displacement field, and then ensure the undetermined parameters of the displacement field according to the principle of minimum potential energy.Ⅲ. Calculate the deformation and load of the cell boundary, then contrast with the load-slip test curve of the connector to ensure the parameter of the wave displacement formula of the cell.