H形钢-木组合梁受弯性能试验研究

Experimental study on flexural behavior of H-shaped steel-wood composite beams

提出一种以焊接H形钢梁为骨架,钢梁翼缘外表面黏结木板组成工字形截面的钢-木组合梁。以组合梁中的木板厚度、钢梁翼缘厚度及宽度、腹板高度为参数,对9根钢-木组合梁进行弯曲性能试验,观察在各级荷载作用下钢板和木板的应变变化、组合梁挠度的发展、破坏过程及破坏形态,探讨其受弯承载力和抗弯刚度等弯曲性能。结果表明,H形钢和木板整体工作性能好,组合效应显著,构件跨中横截面应变呈线性分布。试件荷载-跨中挠度曲线呈弹性和弹塑性两个阶段,最终以下翼缘木材跨中断裂而破坏。随着木板厚度、钢梁翼缘厚度及宽度、腹板高度的增大,试件的承载力呈现不同程度的提高。提出了计算钢-木组合梁跨中挠度及受弯承载力的简化计算式,将其计算结果与试验结果进行对比,结果表明计算式精度较高,可以为钢-木组合梁的应用提供设计依据。

A new type of steel-wood composite beam was presented. It takes welded H-shaped steel as the backbone and glued wood board on the outer surface of the flange of steel,resulting in a steel-wood composite beam with Ishaped cross section. Experimental study on the flexural behavior of nine composite beams was carried out considering the parameters of the thickness of wood,the thickness and width of the flange of steel,the height of the web of steel.The strain in the steel sheet and wood board and the deflection of beam were measured,and the failure process and failure modes were investigated. Then the bending bearing capacity and bending stiffness of composite beams were explored. Experiment results indicate that the H-shaped steel and wood board can form an excellent composite crosssection,and the strain in the composite cross-section is linearly distributed. The load versus span-deflection curve of specimen has elastic and elasto-plastic stages,and the specimen damages because of the fracture of wood at the span of lower flange. The bearing capacity of the specimen shows varying degrees of growth with the increase of the thickness of wood,the thickness and width of the flange of steel,the height of the web of steel. The simplified formulas of calculating the mid-span deflection and bending bearing capacity of composite beams were proposed. The formula results fit well with the experimental results with high accuracy,which can be used as the design basis for the application of composite beam.