Shear Property Of Timber-Concrete Composite Structure With Nail Type Connectors

Timber-concrete composite(TCC)structure is a structure which was firstly used in 1950s.Timber and concrete are conneted by different kinds of shear connetors.It has the advantages of reproducible,energy-saving,easy construction,and good anti-seismic property but without the disadvantages of flammability,corrosion and short dimension,which leads to the spread using in Europe and the USA.To date,researchers in the world have done researches on the static performance of TCC structure.Eventhough,there are some problems need to be worked out:(1)the resuts for monotonic static test for TCC structure,the behavior of TCC structure can not be comfirmed.(2)Researcher has not studied the seismic property of TCC.(3)No special finite element can be used in the Finite software when we do research on the Finite Element analysis.In this thesis,firstly,12 timber-concrete composite push-out samples were tested under monotonic load,and the shear capacities of nail connectors in TCC structure were deducted according to the experimental behavior of TCC structure with nail connectors.Secondly,18 timber-concrete composite push-out samples were tested under reversed load,and the energy-dessipation mechanism of connectors in timber-concrete composite structure was studied.Thirdly,the simulation for monotonic static tests of TCC push-out samples was carried out and finally,the timber-concrete composite beam element was built and the corresponding FEM matrix was presented.The main results are as follows,(4)??????,????-?????????????????????????????????(1)Three failure modes of TCC structure with bolts under monotonic load were analyzed,the influence of dimensions of bolts and concrete strength on the shear strength of bolts in TCC structure,and suggestions for design of TCC structure were presented.(2)The elastic-plastic theory analysis was executed for three failure modes,and the corresponding shear capacity equations were provided for bolt connectors and stud-groove connectors.(3)The reversed cyclic tests for TCC structure with bolts were conducted,the hysteresis behavior and energy dissipation mechanism were analyzed,and the hysteresis model were presented with linear or quadratic equation according to tests under reversed load.(4)Based on virtual work principle,the timber-concrete composite beam were built with Timoshenko beam for timber and concrete seperately,and the composite beam element matrix was carried out according to the elastic-plastic finite element analysis of TCC structure.With the aforementioned study,some comments can be presented to design the TCC bridge.Besides,the pollution in the engineering can be solved and the sustainable development can be realized in the future.