胶合木梁抗弯承载力分析*
- 摘 要
-
(中南林业科技大学土木工程与力学学院, 长沙 410004)
[摘要]胶合木梁抗弯承载力影响因素较多,其计算分析是一个复杂的问题。为了合理评估胶合木梁的抗弯承载力,首先通过胶合木梁的受弯性能试验,系统地分析了胶合木构件的受力全过程,探讨了其破坏形态,研究了尺寸对其抗弯强度的影响。试验结果表明:截面平均应变分布符合平截面假定;抗弯强度随着尺寸的增大而降低,具有明显的尺寸效应。基于Weibull脆性断裂理论模型,得到了落叶松胶合木梁长度与高度的组合尺寸效应系数;提出了一个拉压本构关系模型;并提出了一种胶合木梁的抗弯承载力计算方法。经过与试验结果的对比验证,该方法计算结果与试验结果吻合较好。[关键词]胶合木梁; 抗弯承载力; 尺寸效应系数; 受弯性能; 本构模型中图分类号:TU366.3 文献标识码:A 文章编号:1002-848X(2015)22-0091-06
Flexural capacity analysis of glulam beamsZhou Xianyan, Cao Lei, Zeng Dan, He Chaohong(College of Civil Engineering and Mechanics, Central South University of Forestry and Technology, Changsha 410004, China)Abstract: The flexural capacity of glulam beams is affected by many factors, and the calculating and analysis of the flexural capacity is a complex problem. In order to evaluate its flexural capacity reasonably, through the flexural behavior experiment of glulam beam, the whole mechanical process of glulam member was analyzed systematically and the failure mode was discussed. The size effect on the flexural strength was studied. The results indicate that average strain distribution of section conforms to plane section assumption. The flexural strength decreases with the increase of size and presents obvious size effect. Based on the model of Weibull brittle fracture theory, the composite size effect coefficient of the length and height of the larch glulam beams was obtained. The tensile and compressive constitutive model was put forward. A calculation method of flexural capacity of glulam beams was presented. Through comparison and verification with the experimental results, the calculation results agreed well with the experiment results.Keywords: glulam beam; flexural capacity; size effect coefficient; flexural behavior; constitutive model
*国家林业局公益性行业科研专项(201304504),国际科技合作与交流专项(2014DFA53120),湖南省自然科学基金项目(12JJ5012),湖南省研究生科研创新基金项目(CX2013B351),中南林业科技大学研究生科技创新基金(CX2013A05)。作者简介:周先雁,博士,教授,博士生导师,Email:zxy560805@163.com。