Finite Element Analysis Of Simply Supported Steel And Concrete Composite Beam

Steel-concrete composite beams were developed rapidly in recent years in China.They are more and more widely used in building and bridges, which have beenachieved remarkable economic and social benefits. Currently, the study theory ofsteel-concrete composite beam is mainly elastic design method and plastic designmethods. But there are some deviations between the results of these theoreticalmethods and engineering practices. In order to improve the accuracy of steel-concretecomposite beam theory formula, some scholars modified the theoretical formula onthe basis of a large number of experimental data. However, the modified formula ismore complicated and makes practical engineering applications inconvenient. Finiteelement method as a novel and effective method came into being, it is simple inprinciple, mature and with less assumptions. It can accurately simulate the actualforce situation of the composite beams to get accurate results.This article uses the finite element software ansys12.0to establish model ofsteel-concrete simply supported composite beams and makes calculations. The focusis on deflection and vibration frequency of composite beams, considering the slipeffect. This article also discusses the factors and law of deflection and slipdistribution of composite beams. In this process, the paper mainly completed thefollowing work:（1）Ansys software establish overall model of steel-concrete simply supportedcomposite beams，which using solid45to simulate steel beams and concrete wing，beam188to simulate stud connectors. Ansys Software calculates the slip distributionand maximum deflection of composite beams under a concentrated load on midspan.Comparing the maximum deflection with that calculated by theoretical formula，verifies the correctness of the model.（2）By the analysis of multiple sets of composite beams in flexible workingstage with Ansys software，we get the factors and law of deflection and slipdistribution of composite beams. The deflection and slip of composite beams are bothproportional to the load. Under the same resultant force, the more equally the loaddistributed, the smaller the deflection of simply supported composite beams, the more stable changes of slip, the smaller the maximum slip. With the improvement of thestrength of concrete, the deflection and slip of composite beam will be reduced.However, when the strength of concrete is high, its impact becomes smaller. As thedegree of shear connection of composite beam increases, the maximum deflection andthe slippage will be reduced, but when it reaches full shear connection, the maximumdeflection and slip remains stable.（3）Through the analysis of composite beams with different levels of shearconnection，the paper infers that Reduced rigidity method applies only to thecomposite beams with degree of shear connection between50%to100%.（4）With ansys software for the modal analysis, the vibration frequency ofsteel-concrete composite beam is calculated. It coincides with the result consideringdynamic elastic modulus, stiffness reduction, cross-sectional shear deformation andmoment of inertia, which verifies the correctness of the modal analysis. From theresults, the first three modes are examples of torsional vibration, the fourth is bendingvibration. It indicates that the design of composite beam is unreasonable and thetorsional stiffness should be strengthened.