带脱空缺陷SRCFT短柱的轴压性能分析

Analysis of Axial Compression Performance of SRCFT Short Columns with Void Defects

摘要:

为探究带脱空缺陷钢骨钢管混凝土(SRCFT)短柱的轴压性能和破坏模式,建立了轴压作用下带脱空缺陷SRCFT短柱的有限元模型,分析不同脱空形式下SRCFT短柱的脱空率、钢管强度、钢管厚度、混凝土强度、钢骨强度和钢骨类型等参数,探讨带脱空缺陷SRCFT短柱的轴压性能和破坏模式。结果表明:带脱空缺陷SRCFT短柱的极限承载力随着钢管强度、钢管厚度、混凝土强度、钢骨强度以及钢骨类型的增加而增大。带环形脱空缺陷试件的脱空率在1.1%~3.3%时,试件极限承载力降低19.11%~20.91%;带球冠形脱空缺陷试件的脱空率在2.2%~6.6%时,试件极限承载力降低8.74%~15.77%。随着脱空率的增加,试件极限承载力减小且轴压性能出现一定的削弱。该研究可为带脱空缺陷SRCFT短柱的研究提供理论基础。

Abstract:

In order to explore the axial compression performance and failure mode of steel reinforced concrete filled steel tubular (SRCFT) short columns with initial concrete imperfection, a finite element model of SRCFT short columns with initial concrete imperfection under axial compression is established, the parameters of SRCFT short columns with different gap radio, steel tube strength, steel tube thickness, concrete strength, steel strength and steel type are analyzed, and the axial compression perfor-mance and failure mode of SRCFT short columns with initial concrete imperfection are discussed. The results show that the SRCFT short columns with initial concrete imperfection increase with the increase of steel tube strength, steel tube thickness, concrete strength, steel strength and steel type. The specimens with annular debonding defects exhibited ultimate bearing capacity reductions from 19.11% to 20.91% when the debonding rate increased from 1.1% to 3.3%, while those with spherical cap debonding defects showed capacity decreases from 8.74% to 15.77% corresponding to debonding rates progressing from 2.2% to 6.6%. That is, with the increase of the gap ratio, the ultimate bearing capa-city of the specimen decreases and the axial compression performance is weakened. It can provide a theoretical basis for the study of SRCFT short columns with initial concrete imperfection.