Study On Design Of Flexural Capacity Of Modern Timber-Concrete Composite Beam Bridge

Modern Timber-Concrete Composite structure is a new form of combination with modern timber and concrete.The concrete slab with structural reinforcement is used as the wing plate,the timber slab is processed and glued into the composite timber beam as the web,and the shear connectors are inserted into the interface between the concrete slab and the timber beam to work together.Because of the good tensile properties of timber beam and the good compressive properties of concrete slab,the two materials can make full use of the tensile properties of timber and compressive properties of concrete by working together through shear connectors.When modern Timber-Concrete Composite structure is deformed in bending,axial shear force is generated at the interface between timber beam and concrete slab,and the shear connector transfers the longitudinal shear force,thus restricting the relative slip of timber beam and concrete slab.Compared with traditional wooden bridges,modern Timber-Concrete Composite beam bridges have good integrity,high stiffness and strong fireproof ability.Compared with concrete bridges,composite structures have lighter self-weight,less energy consumption,less environmental pollution and higher recycling efficiency.Nowadays,in many foreign countries,modern Timber-Concrete Composite structures are widely used,especially in the reconstruction and construction of wooden structures.In recent years,with people’s attention to environmental protection,the domestic research on new composite materials ushered in a new upsurge,but the research results on modern Timber-Concrete Composite structures are less,which is in the initial stage,and the research on the integrity of modern Timber-Concrete Composite beam bridges is almost blank.In this paper,based on the analysis of the section stress characteristics and test data of modern Timber-Concrete Composite beams,the calculation model of ultimate flexural capacity of modern Timber-Concrete Composite beam bridge is established,the formula of ultimate flexural capacity of modern Timber-Concrete Composite beam under critical failure state is put forward,and the design parameters of composite beam is optimized,which can provide reference for the design of modern Timber-Concrete Composite beam bridge.At the same time,in order to verify the correctness of the formula,theoretical derivation and non-linear finite element analysis method are used to verify and analyze the existing experimental data.Through theoretical deduction,finite element analysis and comparative analysis of test results,the results show that the theoretical deduction formula is in good agreement with the finite element analysis and test results,and can be applied to the bearing capacity calculation and structural design of modern Timber-Concrete Composite beam bridge.The main research contents are as follows:(1)According to the mechanical characteristics of modern Timber-Concrete composite beams,the calculation model of ultimate flexural capacity of modern Timber-Concrete Composite beam with partial shear connection is established,and the formula of ultimate flexural capacity of composite beam under failure load is put forward.(2)The finite element model of modern Timber-Concrete Composite beam bridge is established by using the large-scale finite element analysis software ANSYS,and the ultimate bearing capacity of the bridge is deduced by numerical analysis,which is compared with the theoretical deduction formula.(3)According to the mechanical characteristics and theoretical formula of modern Timber-Concrete Composite beam,the basic design method of modern Timber-Concrete Composite beam bridge with partial shear connection is obtained.