Study On Dynamic Characteristics Of Composite Beams Based On Concrete Slab-Connectors-Steel Beam Interaction

Because of the advantages of steel-concrete composite beam, it is applied more and more widely in construction engineering. Its self vibration characteristics and dynamic characteristics of the harmonic load caused a lot of attention of scholars at home and abroad. This paper is based on science and technology research projects of Hebei province colleges and universities Study on dynamic characteristics of composite beams of concrete slab-Connectors-Steel beam interaction(ZD2014025). Design of the 3 Connectors shear stiffness parameters of linear combination of test model beam, hammering and harmonic load will be applied to the beams, and establish corresponding finite element models, to study the vibration characteristics and dynamic response rule. The establishment of actual bridge finite element model with different connectivity and span, and theoretic analysis is conducted, to study on the dynamic stiffness reduction coefficient. The main conclusions are as follows:(1)Composite beam vibration frequency value is large, which showing the good performance of combined beam bending and torsion; When the composite beams with the same section and span, but different degrees of connection with concrete slabs and steel, the natural vibration frequency will reduce when the shear connection reduces.(2)The smaller of the Beam stiffness, the more obvious of the slip. The average slip is mainly affected by the static load component, slip amplitude is mainly affected by the load amplitude. Acceleration is mainly affected by the loading frequency and loading amplitude of the cross. The dynamic deflection is mainly affected by the static load component. Loading on the middle bridge stride, the maximum slip does not happen at the end of beam, but at a distance of beam end, there is an inflection point. When it is not loaded in the cross, the maximum slip is still in the end of the beam at a certain distance, and the larger slip near the end of load position.(3)To establish the finite element model of the test beam by ANSYS software, loading the beam to the forced vibration. In the process of analyzing the transient state, the beam into the steady state vibration state requires long time for the process of solving.(4)The dynamic stiffness reduction coefficient plays a very important role in the calculation of beam stiffness, and the higher the order, the greater the reduction coefficient...