Research On The Mechanical Performance Of Concrete Partially-Filled Steel Box Continuous Composite Beams

The steel-concrete combination structure is a combination of steel and concrete in a specific way to form a structure that can give full play to the respective properties of these two materials.However,because the concrete material is easy to crack under the tensile force,the traditional steel-concrete continuous composite beam is easily affected by the cracking of the upper concrete in the negative moment zone,which reduces the durability of the structure,and the lower steel beam is under compressive stress.It is also prone to local buckling under the action,thereby reducing the bearing capacity of the structure.In order to improve this disadvantageous situation,this paper proposes a partially filled steel box-concrete composite continuous beam,mainly by filling concrete in the steel box below the negative moment zone of the composite beam,making full use of the characteristics of high compressive strength of concrete materials.At the same time,the presence of concrete also limits the inward buckling of the steel box,which improves the local stability of the steel box.In this paper,with the support of the National Natural Science Foundation of China,the experimental research on the mechanical properties of five partially filled steel box-concrete continuous composite beams is carried out.Based on the experiments,the theoretical calculations and finite element simulations are combined.Finally,the experimental values and theoretical calculations are calculated.The values and finite element simulation values are compared,and various factors affecting the bending bearing capacity of a partially filled steel box-concrete continuous composite beam are analyzed.A deeper understanding of the bending bearing capacity of the composite beam is obtained.The specific results are as follows:(1)Completed the static loading test of 5 test beams,described the test phenomena during the loading process of the test specimens,analyzed the causes of the related phenomena,and then sorted the test data.(2)The influences of different reinforcement ratios,shear connection,filling types and slip effects on the bending bearing capacity were analyzed,and the formula for calculating the bending bearing capacity of the negative moment zone of the bearings in the continuous composite beam was derived.(3)By comparing and analyzing the actual measured value with the theoretical calculated value,it is found that the error between the two is small,which indicates that the calculation method deduced in this paper has certain feasibility and can provide a reference for subsequent research.(4)The ANSYS finite element software is used to simulate the stress process of the test beam.The simulation results are in good agreement with the experimental measured results.The conditions reflected by the simulated cloud diagrams are basically consistent with the experimental phenomena,indicating that the finite element model built this time It is accurate and reliable,and can truly reflect the force characteristics of partially filled steel box-concrete continuous composite beams.