Research On Mechanical Performance And Connection Properties Of H-Steel-Wood Composite Beams

Steel and wood have their own advantages,also have their own defects.The steel-wood composite structure can make use of their respective performance advantages to achieve the complementarity of performance.This study proposes a steel-wood composite beam connected by hot-rolled H steel and imported SPF specification material,mechanical properties testing was done.Based on the test results,put forward the bearing capacity formula of steel-wood composite beam,and the simulation of steel-wood composite beam used ANSYS finite element software.The following conclusion were drawn:(1)When the shear span ratio is 2,the compressive strain is greater than the tensile strain,and the result of the shear span ratio of 4 is the opposite.When the shear span ratio is 3,the compressive strain of the specimen is equivalent to the tensile strain.With the increase of shear span ratio,the ultimate displacement,ductility coefficient,energy and the maximum tensile strain increased,the load,initial stiffness and the maximum compressive strain decreased,the stress neutral layer moved down.The load and initial stiffness of 300mm bolt spacing specimens are higher than those of 200mm spacing specimens.(2)The stiffness of the steel-wood composite beams is mainly contributed by the H steel,and the tensile properties of the steel have been better played in the composite beams.The load,ultimate displacement,ductility coefficient and energy dissipation capacity of the steel-wood composite beams were all higher than that of the pure steel beams.The load,final displacement and energy consumption of the bolt connection specimens were higher than that of the self-tapping screw connection.There is little difference in bearing capacity between 200mm and 300mm specimens,but the final displacement,ductility and energy consumption of 300mm bolt spacing specimens are higher than those of 200mm spacing specimens.(3)The shear strength of steel-wood composite beams is mainly contributed by H steel web,and the calculated value of shear bearing capacity is in good agreement with the test value,the average error is 8.7%.The calculation formula of flexural rigidity and bending bearing capacity are in good agreement with the test value,the average error is less than 5%.The finite element simulation deformation and the simulation stiffness are in good agreement with the test results,the relative errors are less than 10%.The simulated equivalent stress results coincide with the test results and the failure mode.(4)According to the test results and simulation results,wood and H steel work well together in the composite beams.The main function of wood is to slow down the overall buckling of H steel.At the same time,the connection node weakens the local buckling caused by concentrated load,which makes the steel performance better and further improves the performance of the composite beam.