不同倒角形式对空腹梁受力性能影响的试验研究

Experimental study on influence of different chamfering forms on mechanical properties of hollow beams

为研究空腹梁的承载力和挠度受设置倒角与否、倒角形式、开孔尺寸大小、孔洞长高比及孔洞分布等因素的影响程度,通过改变各影响因素,设计了5根试验梁进行承载力和挠度试验,并与Abaqus模拟结果对比。结果表明:当达到挠度容许值时,抗剪键与梁肋交接点处不设置倒角的空腹梁承载力只有设置倒角空腹梁的80%左右;设置等腰直角三角形倒角与设置1/4圆弧倒角对空腹梁承载力的影响不大;孔洞长高比是影响空腹梁承载力的一个重要因素,孔洞长高比取2左右为宜;倒角与梁肋交接点处为空腹梁的薄弱部位;构造措施合理的空腹梁承载力受挠度控制,挠度试算时其等效惯性矩可取实腹梁理论惯性矩的55%。

In order to study the influence degree of chamfering setting,chamfering form,opening size,hole distribution and length-to-height ratio on the load bearing capacity and deflection of hollow beam,the deflection and load bearing capacity of five beams were tested by setting various parameters,and the results were compared with the emulation results with Abaqus program.The results show that when the deflection limit is reached,the load bearing capacity of hollow beams without chamfering at the joint of shear key and rib is only about 80% of that with chamfering;there is little difference on load bearing capacity of hollow beams between setting isosceles right triangle chamfering and setting 1/4 arc chamfering;the length-to-height ratio of the hole is an important factor affecting the load bearing capacity of hollow beams,with the optimized length-to-height ratio being about 2;the joint of the chamfering and the rib is the weak part of hollow beams;when the hollow beam is constructed reasonably,its load bearing capacity is controlled by deflection,and the equivalent inertia moment of the hollow beam can be taken as 55%of the theoretical value of the solid web beam for deflection calculation.