Effect Of Crack Opening And Closing On Reversed Hysteretic Behavior Of Reinforced Concrete Structures

For the complexities in the nonlinear behavior of reinforced concrete structures, the analysis results showed a wide variation in predictions of seismic response,and even wider divergence in computed deformation responses.Lacking the cracked concrete model under combined is the important causation.Based on the available testing data and research results, large amount work of establishing crack opening and closing model under monotonic and cyclic loading has been done. Provide crack opening and closing model under monotonic and cyclic loading for reinforced concrete research of our team.In the paper the main work has been done as following:1. Crack opening and closing model was established by the author to describe the crack opening and closing behavior. A series of shear panel under monotonic and cyclic loading tesetd at the University of Toronto and Houston were considered.2. On the basis of previous research in our group, element stiffness matrix and element restoring force matrix of concrete and steel strain-stress elements were integrated into FEAPpv to form user-defined element module. Displacement controlled loading algorithm which provided by FEAPpv was used in the program.3. Comparison of the computed results with tested ones was carried out in both loacl and overall responses to verify the finite element modelling of crack opening and closing in this thesis.4. Simulation of tested panels and walls under monolithic and cyclic loading was undertaken.The following achievements have been obtained:1. Based on the available testing data and research results, large amount work of establishing crack opening and closing model under monotonic and cyclic loading has been done.2. Comparison of the computed results with tested ones was carried out to verify the accuracy and reliabity of nonliner analysis program.3. The analysis procedure can preferably predict carrying capacity of shear panel under monotonic loading and reversed loading, manifest the pinch of shear panel under reversed loading, and simulate deformation Effects of shear-walls of which H/B is 2.5. But because loading and unloading linearly of simulation is one of main causations, and plastic strain equation has certain effect on curves'satiation, hysteresis curves' undoading sect of simulation doesn't fit in with that of tests.