單階柱上下柱彈塑性階段的相互作用
童根樹,黃山
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(浙江大學建筑工程學院,杭州 310058)[摘要]單階柱屈曲時上、下柱存在相互作用,對頂端自由和頂端受轉(zhuǎn)動約束的階形柱進行了彈塑性有限元極限承載力分析,研究了這種相互作用在彈性階段和彈塑性階段的變化。結(jié)果表明,在彈塑性階段,這種相互作用總是朝著增加階形柱的承載力方向變化,說明目前規(guī)范采用依據(jù)彈性假定確定的計算長度系數(shù),應用于彈塑性工作的柱子是偏于保守的。通過分析彈塑性階段上、下柱相對剛度的強弱的變化和柱頂彈性約束相對于柱子剛度的變化,對產(chǎn)生這種結(jié)果的原因進行了分析。[關鍵詞]彈塑性階段;階形柱;相互作用Elastic-plastic interaction between upper and lower columns of singly-stepped columnsTong Genshu, Huang Shan(Department of Civil Engineering,Zhejiang University,Hangzhou 310058,China)Abstract:There is an interaction between upper and lower columns in the sway-buckling of singly-stepped columns. Finite element analysis of the load-carrying capacity of top free and rotationally restrained stepped columns in the elastic-plastic stage was carried out to study the influence of the interaction in elastic stage and elastic-plastic stage. It is found that the interaction in the elastic-plastic stage always increases the overall load-carrying capacity of the stepped columns, which verifies the conservativeness of the current code method where elastic effective length factors are used regardless of the stress level of the columns. Explanations are presented on such results by changing the relative rigidity between the upper and lower columns, and that between the elastic rotational restraints and the stepped columns.Keywords:elastic-plastic stage; stepped column; interaction作者簡介:童根樹,博士,教授,Email:tonggs@ccea.zju.edu.cn。參考文獻[1]王金鵬.考慮層與層相互作用的框架穩(wěn)定分析[D]. 杭州:浙江大學,2003.[2]季淵,童根樹.有吊車作用柱腳鉸接門式剛架柱的計算長度[J]. 建筑結(jié)構,2003,33(6).[3]童根樹,胡達明,姚諫.帶擺柱門式剛架的穩(wěn)定性[J]. 建筑結(jié)構,1999,29(10).[4]童根樹.鋼結(jié)構的平面內(nèi)穩(wěn)定[M]. 北京:中國建筑工業(yè)出版社,2007.[5]GB50017—2003鋼結(jié)構設計規(guī)范[S].北京:中國計劃出版社,2003.[6]陳驥.鋼結(jié)構穩(wěn)定理論與設計[M]. 北京:科學出版社,2001.[7]陳紹蕃.鋼結(jié)構設計原理[M]. 北京:科學出版社,2005.[8]沈祖炎,陳揚驥,陳以一.鋼結(jié)構基本原理[M]. 北京:中國建筑工業(yè)出版社,2005.