基于广义梁理论的非线性材料薄壁受压构件屈曲荷载计算方法

GBT-based Buckling Loads Formula of Non-linear Thin-walled Compressed Members

提出适用于非线性材料的广义梁理论屈曲荷载计算方法,并对不锈钢薄壁受压构件屈曲荷载进行计算验证。通过定义材料非线性应力应变关系和瞬时弹性模量,对传统线弹性广义梁理论进行修正,建立非线性材料薄壁构件受压屈曲荷载计算方法,推导不锈钢薄板受压局部屈曲、冷弯薄壁不锈钢卷边槽形柱畸变屈曲及箱形不锈钢长柱弯曲屈曲荷载计算公式,并与既有试验数据对比。经验证,线弹性分析方法不适用于不锈钢材料;提出的修正GBT法具有较高精度,且本构关系采用变形法则结果偏于安全,可用于不锈钢等非线性金属材料薄壁构件受压屈曲荷载的确定,为研究和设计提供理论指导。

A buckling loads formula based on Generalised Beam Theory（GBT） was proposed,which could be used in non-linear elastic metallic materials thin-walled compressed members,such as stainless steel.By introducing non-linear stress-strain relations and instantaneous elastic modulus,the modifications were incorporated in the conventional GBT,and the expressions were formulated to calculate buckling loads of stainless steel members buckling in local,distortional and global modes.Compared with the existed test results,it is shown that linear elastic method cannot deal with stainless steel,while the results of proposed method are much more reliable.Moreover,the modified GBT method with deformation plasticity theories produces safer results,which could be used in determining buckling loads of non-linear metallic materials thin-walled members in compression,as well as structural design and further researches.