短剪切型消能梁段的力学性能及其影响因素研究

STUDY OF MECHANICAL PROPERTIES AND ITS INFLUENCE FACTORS FOR SHORT SHEAR LINKS

已有研究表明,长度比小于1.0的短剪切型消能梁段与普通剪切型消能梁段的超强系数和塑性转角存在较大差异。该文基于Q235和Q345钢材,设计108个考虑加劲肋间距、翼缘与腹板面积比、翼缘强度和跨高比等因素的模型,并采用与已有试验结果对比验证的有限元分析方法,详细研究短剪切型消能梁段的力学性能及各因素的影响规律。结果表明,短剪切型消能梁段的超强系数和塑性转角分别能达到1.90和0.13,加劲肋间距系数和翼缘宽厚比可分别放宽至40和10(235/f_y)^(1/2)。另外,增大翼腹比可有效提高短剪切型消能梁段腹板受剪屈服后的承载力,但改变翼缘强度和跨高比对其性能无明显影响。

Recent researches on the performance of short shear links with length ratio smaller than 1.0 have shown that the overstrength and inelastic rotation are much greater than the requirements of current specification.In order to re-evaluate the mechanical properties of short shear links,an analytical study is conducted to investigate the influence factors on the overstrength and inelastic rotation,which are based on the material properties of Q235 and Q345 steel.Finite element models are verified by comparison of theoretical results with experiments results,which are then used to investigate the performance of 108 short shear links,including the stiffener spacing,flange to web area ratio,flange strength and link length to depth ratio.The results indicate that the overstrengh coefficient and inelastic rotation of short shear links can reach 1.90 and 0.13 respectively.Furthermore,the normalized stiffener spacing and flange width-thickness ratio can be relaxed to 40 and y 10 235/f.Increase of the flange to web area ratio can effectively improve the short shear link strength after the web is fully yielded in shear,but the flange strength and link length to depth ratio have very limited difference on the behavior of short shear links.