压弯构件的附加弯矩分析

利用压弯构件的弹性曲线微分方程,分析了轴向压力对压弯构件弯曲变形的影响,导出了各种压弯构件附加弯矩的统一算式.通过实例,定量分析了各种因素对弯矩比(附加弯矩与横力弯矩的比)的影响,给出了可忽略压弯构件附加弯矩的判定条件.研究结果表明,弯矩比与横向荷载的大小无关.当外力给定时,抗弯刚度越大,弯矩比越小;当轴向压力给定时,杆端约束越强,弯矩比越小.当轴向压力与临界压力的比值给定时,杆端约束越强,弯矩比越大.

Analysis of Additional Moments of Beam-columns

The effects that axial compressive forces produce on the bending deformation of beam-columns are analyzed using differentiating equations about elastic deformation of beam-columns.Meanwhile,the deduction of unified equations of various beam-columns' additional moments and the discussion of the effects that factors of sorts exert on additional moments are also performed.The quantitative analysis of the relationship between additional moment and side force bending moment is conducted via practical case and the criteria of the ignorance of beam-columns' additional moments are presented.The results reveal that moment ratio(ratio of additional moment to side force bending moment) has nothing to do with the side force;external forces given,the higher the value of EI is,the smaller the moment ratio is;axial compressive force given,the stronger the restriction of the ends of elements is,the smaller the moment ratio is.When ratio of axial compressive force to critical compressive force remains invariable,the stronger the restriction of the ends of elements is,the higher the moment ratio is.