Size effect on axial compressive failure of CFRP-wrapped square concrete columns: Tests and simulations
Size effect on axial compressive failure of CFRP-wrapped square concrete columns: Tests and simulations
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DOI：
10.1016/j.compstruct.2020.112843
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发表时间：
2020-12-15
影响因子：
6.3
通讯作者：
Du, Xiuli
中科院分区：
文献类型：
--
作者：
Jin, Liu;Chen, Huiming;Du, Xiuli
为了提高混凝土柱的轴压承载能力，碳纤维复合材料(CFRP)已被广泛应用于混凝土柱的包裹。本文采用试验和数值模拟相结合的方法，研究了碳纤维布包裹方形混凝土柱的尺寸效应。设计了30根几何形状相似的CFRP包裹混凝土柱，其最大截面宽度为600 mm，并进行了反复轴压试验。探讨和测试了荷载类型、结构尺寸和配筋方式对柱破坏的影响。此外，还利用考虑混凝土异质性和CFRP-混凝土相互作用影响的三维细观模拟方法，进一步研究了CFRP缠绕柱的尺寸效应。在三维细观模拟中，分析了结构尺寸较大、CFRP纤维掺量较大的柱的破坏情况。详细研究和讨论了尺寸效应对碳纤维布缠绕柱名义抗压强度的影响。最后，建立了描述CFRP包裹混凝土柱的尺寸效应的更新尺寸效应定律(SEL)。经验证，修正后的SEL是合理的，与目前的实验数据和模拟结果吻合较好。
Carbon Fiber Reinforced Polymer (CFRP) has been widely utilized to wrap concrete column in order to improve the axial compressive bearing capacity. In this study, the size effect of CFRP-wrapped square concrete columns was investigated using both experimental and numerical approaches. A total of 30 geometrically-similar CFRP-wrapped concrete columns with a maximum cross-sectional width of 600 mm were designed and tested with repeated axial compression. The influences of loading type, structural size and reinforcement configuration on the failure of the columns were explored and measured. Moreover, a 3D meso-scale simulation approach considering the influence of concrete heterogeneity and CFRP-concrete interactions was utilized to furtherly investigate the size effect of CFRP-wrapped columns. In the 3D meso-scale simulations, the failure of columns with larger structural sizes and larger CFRP fiber ratios was analyzed. The size effect on the nominal compressive strength of CFRP-wrapped columns was examined and discussed in detail. Finally, an updated size effect law (SEL) was established to describe the size effect in CFRP-wrapped concrete columns. The updated SEL is proved to be reasonable, which shows good consistence with the present experimental data and simulation results.