- 摘 要
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郭立湘 （浙江杭蕭鋼構(gòu)股份有限公司 杭州 310003）童根樹 （浙江大學土木系 杭州 310027）
[提要] 對壓彎構(gòu)件在跨中設(shè)置側(cè)向支撐和扭轉(zhuǎn)支撐時的穩(wěn)定性進行研究，先就一般情況建立平衡微分方程，推導出壓彎構(gòu)件的穩(wěn)定臨界方程，在此穩(wěn)定臨界方程的基礎(chǔ)上對偏心支撐壓彎構(gòu)件進行詳細的分析，得到了使壓彎構(gòu)件計算長度減半的扭轉(zhuǎn)支撐臨界剛度表達式和側(cè)向支撐臨界剛度表達式，導出了判斷支撐是否能使壓彎構(gòu)件計算長度減半的臨界荷載偏心。此外還分析了非完全支撐時支撐剛度和構(gòu)件承載力的關(guān)系，以及側(cè)向支撐、扭轉(zhuǎn)支撐及兩者聯(lián)合作用對構(gòu)件承載力的影響，推出了上面所有分析的解析式。
[關(guān)鍵詞] 支撐 梁-柱 壓彎構(gòu)件 剛度 彎扭屈曲 計算長度The elastic stability of beam-column with lateral and torsional braces at mid-span is studied. Firstly the stability critical equation of laterally and torsionally braced beam-column is derived. Based on the equation derived, the formulae for critical bracing stiffness( either lateral brace or torsional brace) and critical load eccentricity are presented which can have the effective length of beam-column. Then the load capacity is investigated when the brace can't halve the effective length of beam-column and the relationship between load capacity and bracing stiffness is presented. Moreover, effect of lateral brace's location on the load capacity of beam-column and co-action of lateral and torsional braces are studied. And the closed-form solutions are given.
Keywords: brace; beam-column; bracing stiffness; flexural-torsional buckling; effective length
