| 引用本文: | 路延,周天华,李文超,吴函恒.冷弯薄壁受压C形截面局部屈曲荷载和承载力[J].哈尔滨工业大学学报,2017,49(6):72.DOI:10.11918/j.issn.0367-6234.201607058 |
| LU Yan,ZHOU Tianhua,LI Wenchao,WU Hanheng.The critical local buckling load and ultimate strength of cold-formed thin-walled C-sections under axial compression[J].Journal of Harbin Institute of Technology,2017,49(6):72.DOI:10.11918/j.issn.0367-6234.201607058 |
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| 摘要: |
| 为研究板组效应对冷弯薄壁受压C形截面局部屈曲荷载和承载力的影响，对组成其截面各板件局部屈曲时的变形协调情况进行理论分析，提出考虑该效应的腹板局部屈曲计算模型，基于能量法和静力平衡条件推导了冷弯薄壁受压C形截面局部屈曲荷载的解析解，并分别与有限条法和中国规范GB 50018—2002规定的方法进行对比.将所推导的解析解引入直接强度法，对21根冷弯薄壁C形受压短柱试验的承载力进行计算，并分别与承载力试验结果和按GB 50018—2002规定方法计算的承载力进行对比分析.结果表明：在屈曲荷载方面，本文推导的解析解合理可靠，而按中国规范规定的方法则存在系统误差，当截面高宽比小于4.5时，其结果偏于保守，当截面高宽比大于4.5时，其结果偏于不安全; 在承载力方面，按本文方法计算的承载力与试验结果较为接近，合理可靠，而按中国规范规定方法计算的承载力较保守，并且随着截面宽高比的增大，保守趋势不断增大.
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| 关键词: 冷弯薄壁型钢 C形截面 板组效应 局部屈曲荷载 极限承载力 |
| DOI：10.11918/j.issn.0367-6234.201607058 |
| 分类号:TU392.1 |
| 文献标识码:A |
| 基金项目:国家自然科学基金(51508029)； 高等学校博士学科点专项基金(20110205110006) |
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| The critical local buckling load and ultimate strength of cold-formed thin-walled C-sections under axial compression |
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LU Yan,ZHOU Tianhua,LI Wenchao,WU Hanheng
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(Department of Civil Engineering, Chang’an University, Xi’an 710061, China)
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| Abstract: |
| To study the plate-assembly effects on the local buckling loads and ultimate strength of cold-formed thin-walled C-sections, the cross-sectional deformation of each plate of the C-section with respect to local buckling was analyzed and an analytical web local buckling model was proposed considering the plate-assembly effects. Based on the energy method and equilibrium conditions, an analytical formula for thin-walled compressed C-sections was derived. The derived formula was verified by the finite strip method and the Chinese code GB 50018—2002, respectively. The ultimate strengths of 21 cold-formed C-section columns under compression were calculated by adopting the analytical formulae in the direct strength method and compared with the test results and the results calculated by the Chinese code GB 50018—2002, respectively. The results show that the derived formula is reasonable and reliable for the local buckling loads, whereas the Chinese code brings out systematic errors, namely conservative results for the depth of web to width of flange ratio less than 4.5 and unsafe results for the depth of web to width of flange ratio more than 4.5. As for the ultimate strength, the results from the proposed method agrees well with the test results, which indicate that the proposed method is reasonable and reliable. In contrast, the Chinese code are conservative with respect to the tests results and the difference between the Chinese code and the test result increases as the depth of web to width of flange ratio increasing.
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| Key words: cold-formed steel C-sections plate-assembly effects local buckling load ultimate strength |
