端弯矩作用下侧向支承钢梁的临界弯矩研究

彭代斌; 刘占科

doi:10.13204/j.gyjzG20082506

端弯矩作用下侧向支承钢梁的临界弯矩研究

doi: 10.13204/j.gyjzG20082506

彭代斌,
刘占科^,

兰州大学西部灾害与环境力学教育部重点实验室, 土木工程与力学学院, 兰州 730000

基金项目:

国家自然科学基金项目(51308272)。

详细信息

作者简介:
彭代斌,男,1994年出生,硕士。

通讯作者:
刘占科,男,1981年出生,博士,副教授,liuzhk@lzu.edu.cn。

计量
- 文章访问数: 81
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- PDF下载量: 3
- 被引次数: 0
出版历程
- 收稿日期: 2020-08-25
- 网络出版日期: 2023-05-25
- 刊出日期: 2023-02-20

Research on Critical Moment of Lateral Restrained Beams Under End Moments

PENG Daibin,
LIU Zhanke^,

Key Laboratory of Mechanics on Disaster and Environment in Western China, the Ministry of Education of China, and College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, China

摘要

摘要: 为建立端弯矩作用下等间距布置侧向支承简支钢梁临界弯矩的计算方法,取两侧向支承点之间的各梁段为简支梁,分析了各梁段的端弯矩比例系数随支承钢梁端弯矩比例系数和侧向支承数量变化而变化的特征,取支承钢梁最大端弯矩所在梁段为两端简支的计算梁段,采用理论分析和数值模拟相结合的方法,揭示了纯弯工况和非纯弯工况下计算梁段与其他梁段的相关关系,得到了支承数量n=1~4时计算梁段临界弯矩系数C₁的数值和相关作用系数α的表达式,把支承钢梁临界弯矩的计算转化为计算梁段临界弯矩的计算。最后,分别采用系数C₁和α以及现行国家标准的临界弯矩计算方法计算了支承钢梁的临界弯矩,并与有限元数值进行对比,验证了系数C₁和α以及现行国标的临界弯矩计算方法的精度。研究表明,系数C₁和α在侧向支承钢梁临界弯矩的计算上具有较高的精度,而GB 50017-2017《钢结构设计标准》中的β_b系数和GB 50018-2002《冷弯薄壁型钢结构技术规范》中的C₁系数,在纯弯工况下具有较高的精度,而非纯弯工况时则存在偏不安全或偏过于安全的情况。
- 侧向支承钢梁 /
- 端弯矩 /
- 计算梁段 /
- 临界弯矩 /
- 相关作用系数
Abstract: In order to establish the calculation method for the critical moment of simply-supported steel beams with lateral restraints equally distributed along the span, the segments between two lateral restraints were treated as simply-supported steel beams firstly. Then, the characteristic of the end moment ratio for these segments were revealed for variable number of lateral restraints and end moment ratio of lateral restrained steel beams. A segment with the maximum end moment of the lateral restrained steel beam, which named as the calculated segment, was selected for determining the critical moment. The interaction between the calculated segment and other segments were analyzed and revealed for pure bending and impure bending theoretically and numerically. Values of the coefficient C₁ and the expressions of the interaction coefficient α were proposed, by which the calculation of the critical moment for lateral restrained steel beams was transformed to the calculation of the critical moment for the calculated segment. Finally, comparisons were carried ont between the critical moments obtained from the proposed method, the method in current design standards and the numerical results. The results showed that the values of the coefficient C₁ and the expressions of the interaction coefficient α were accurate enough for determining the critical moment of lateral restrained steel beams subjected to end moments, while the β_b coefficient provided in Standard for Design of Steel Structures (GB 50017-2017) and the C₁ provided in Technical Code of Cold-Formed Thin-Wall Steel Structures (GB 50018-2002) were accurate for pure bending, but for impure bending, unsafe or too safe predictions were generated.
- lateral restrained steel beams /
- end moments /
- calculated segment /
- critical moment /
- interaction coefficient

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参考文献(10)

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