- 摘 要
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(1 東北石油大學黑龍江省高校防災減災工程與防護工程重點實驗室， 大慶 163318；2 香港理工大學土木與環(huán)境工程系， 香港 999077)
［摘要］為研究實腹式雙鋼管異強混凝土(CFDST)組合短柱的軸壓性能，以長細比（λ）、核心混凝土和夾層混凝土抗壓強度 (fcki，fcko)、內(nèi)外鋼管厚度(ti，to)、直徑(Di，Do)及抗拉強度(fyki，fyko)為主要參數(shù)，共設計21根CFDST組合短柱?；阡摬暮喕碾p線性本構(gòu)模型和考慮約束效應的核心、夾層混凝土非線性本構(gòu)模型，采用ABAQUS軟件對18根雙鋼管混凝土組合短柱試件進行了數(shù)值仿真，獲得短柱豎向荷載-位移關(guān)系曲線。通過與已有的試驗數(shù)據(jù)對比，驗證了材料本構(gòu)模型和有限元建模的合理性?；诖藢FDST組合短柱進行擴展參數(shù)分析，考察了不同參數(shù)對該類短柱軸壓承載力的影響規(guī)律，獲得此類構(gòu)件的受力機理、應力分布規(guī)律及破壞形態(tài)。結(jié)果表明，隨fcki，to，Do和fcko的增大，CFDST組合短柱的軸壓承載力均會顯著提高。而隨λ的增加，CFDST組合短柱的軸壓承載力卻逐漸減小。所有試件均表現(xiàn)出較優(yōu)越的持荷能力和中部外凸膨脹的破壞形態(tài)。由圓心向外CFDST組合短柱的約束效應逐漸遞減。最后，引入內(nèi)外管的約束效應系數(shù)（ξi，ξo），采用1stOpt軟件統(tǒng)計回歸出CFDST組合短柱軸壓承載力計算表達式, 并給出該類短柱的相應設計建議，為該類新型組合柱在實際工程中推廣應用奠定基礎。
［關(guān)鍵詞］約束效應； 軸壓承載力； 受力機理； 長細比； 本構(gòu)模型
中圖分類號：TU398-7文獻標識碼：A文章編號：1002-848X(2020)05-0120-10
Research on axial compression bearing capacity of different-strength concrete filled double steel tube short columns
Ji Jing1,2, Yu Dianyou1, Jiang Liangqin1, Liu Yingchun1, Yang Maomao1, Song Huayu1, Jiang Li1
(1 Heilongjiang Key Laboratory of Disaster Prevention, Mitigation and Protection Engineering, Northeast Petroleum University, Daqing 163318, China; 2 Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hongkong 999077, China)
Abstract:To investigate axial compression performance of different-strength concrete filled double steel tube (CFDST) short columns, 21 CFDST short columns were designed considering main parameters of slenderness ratio (λ), compression strength of core and sandwich concrete (fcki, fcko), thickness of inner and outer steel tubes (ti, to) and diameter of inner and outer steel tubes (Di, Do), and tensile strength of inner and outer steel tubes (fyki, fyko). Based on the simplified bilinear constitutive model for steel tubes and nonlinear constitutive models for core and sandwich concrete considering the constraint effect, numerical simulation analysis of 18 CFDST short columns was carried out by using software ABAQUS, and vertical load-displacement curves were obtained. The rationality of the material constitutive models and finite element (FE) model was verified by comparing with existing experimental results. The parameter analysis for CFDST short columns were conducted and the influence of different parameters on axial compression bearing capacity was investigated. Then the force mechanism, stress distribution and failure mode of short columns were obtained. The results show that axial compression bearing capacity of CFDST short columns increases significantly by increasing of fcki, to, Do, and fcko. However, with the increasing of λ, axial compression bearing capacity of CFDST short columns decreases gradually. All specimens show superior load-holding capacity and convex expansion failure modes in the middle of specimens. Constraint effect of CFDST short columns decreases gradually from the center to the outside. Finally, by introducing constraint effect coefficient (ξi, ξo) of inner and outer steel tubes, the expression of axial compression bearing capacity of CFDST short columns was established by 1stOpt software, and the design suggestions of this kind short column were also given, providing basis for popularization and application of this kind of new composite columns in practical engineering projects.
Keywords:constraint effect; axial compression bearing capacity; stress mechanism; slenderness ratio; constitutive model
*國家自然科學基金面上項目(51178087)，黑龍江省級領軍人才梯隊后備帶頭人資助項目(RCHB-2015-1)，哈爾濱工業(yè)大學結(jié)構(gòu)災變與控制教育部重點實驗室開放基金項目（HITCE201908），黑龍江省教育廳科研專項 (2016YSFX-02)，東北石油大學研究生創(chuàng)新科研項目(JYCX_CX05_2018)。
通訊作者:姜良芹，碩士，副教授，Email: jiangliangqin 1978@163.com。
