开口截面钢-混凝土组合梁弯扭性能的理论分析与试验研究

EXPERIMENTAL ANALYSIS ON STEEL-CONCRETE COMPOSITE BEAMS WITH OPEN SECTION UNDER COMBINED FLEXURE AND TORSION

对 3根不同扭弯比的开口截面组合梁弯扭进行试验分析得出组合梁的弯型和扭型两种破坏形态。将组合梁划分成三维 8结点实体单元 ,用有限元方法对组合梁在弯扭作用下的工作性能进行了弹性理论分析 ,建立了弯扭强度M -T相关公式。通过编制组合梁截面的弯矩 -曲率全过程计算程序 ,得出了混凝土翼板受力与截面弯矩之间的关系 ,从而阐明了弯扭共同作用下组合梁的受力机理 ,建立了极限状态的弯扭强度M -T相关公式 ,并分析了组合梁截面参数对相关曲线的影响。

piece of specimens with varied ratios of torsion to bending moment were tested under combined flexure and torsion.Failure modes of tested combined beams are described in details and divided into two types:failure with flexural featuer and failure with torsional featuer. With spatial finite elements of 8 nodes,behavior of combined beams under combined flexure and torsion was analyzed based on elastic theory,and correlation curve between flexure and torsion was derived.By means of computing program for full relevant curve between bending moment and curvature of combined beams,the relationship between stress and bending moment of concrete Slab was proposed,and working mechanism of combined beams under combined flexure and torsion was clarified thereby.Correlation formula between flexural strength and torsional strength in ultimate state was given. Some factors of section,which may have effect on correlation curve,were also analyzed.