Compression Performance Of Axially Loaded H-shaped Steel Column Strengthened With Bonded Steel Plate

Steel structures have been widely used in practical engineering due to their light weight and high strength.However,the reinforcement of steel structural members is still a major problem in the engineering field.At present,China has formulated relevant normative standards to guide the reinforcement of steel structures,including methods such as increasing the section and adding fulcrums.Paste plate reinforcemen is one of the most efficient steel structure reinforcement methods.The structural adhesive is used to bond the thin steel plate with the defective steel structural member to form an overall force system to improve the strength,rigidity a nd stability of the original component.Compared with the traditional welding reinforcement method,the paste plate reinforcemen method avoids the adverse effects of welding residual stress and welding crack on the structure,moreover,it has the advantages of simple and quick construction without high temperature gas,and good economic benefits..The axial compressive static test included three H-shaped steel columns strengthened by flange-bonded steel plates and one unreinforced H-shaped steel column.and the thickness of the thin steel plate and the spacing of the anchor bolts were respectively changed.Study on the influence of the reinforcement of the bonded steel plate on the bearing capacity and stiffness of the H-shaped steel column by measuring the strain and deformation of the test piece.In addition,the test results were compared with the theoretical results calculated by codes.The results show that the method of reinforcing the steel plate can significantly improve the axial bearing capacity and rigidity of the H-shaped steel column,increase the thickness of the steel plate,reduce the bolt spacing,and the reinforcing effect is better.The results provide a test basis for the normative formula,and have practical value in engineering.The stiffness of the section of the reinforced steel column is abrupt due to the discontinuity of the bonding material at the end of the reinforcing member,which causes the stress distribution to concentrate on the end of the reinforcing member.therefore,the reinforcing steel plate and the steel structure are prone to premature peeling failure when the material strength does not reach the ultimate strength.In order to ensure the reinforcement effect,it is necessary to analyze the interface stress because the bond interface stress plays a decisive role in the peeling damage.Establish the equilibrium differential equation and the calculation formula of the interface shear stress of the micro-element in the state of micro-deformation by linear elastic theory,analyze the relevant parameters in the formula.The results show that the maximum interface shear stress appears at the end of the reinforcement member and the interface shear stress is related to the thickness of the rubber layer,the structural elastic modulus,the thickness of the bonded steel plate and the initial eccentricity.Finally,the test column was modeled and analyzed by ABAQUS,and the test process and stress state of the steel plate reinforced steel column were simulated.Study the shear stress distribution and its variation law of the bond interface during the test,and use different models to the rubber layer.Perform the simulation.The finite element calculation results of the shear stress of the bonded interface further show that the theoretical derivation of the interface shear stress is accurate.The numerical analysis results of the bearing capacity are compared with the experimental values to verify the accuracy of the model.