膠合木梁抗彎承載力分析*
周先雁，曹磊，曾丹，何朝紅
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（中南林業(yè)科技大學(xué)土木工程與力學(xué)學(xué)院, 長沙 410004）
［摘要］膠合木梁抗彎承載力影響因素較多，其計算分析是一個復(fù)雜的問題。為了合理評估膠合木梁的抗彎承載力，首先通過膠合木梁的受彎性能試驗，系統(tǒng)地分析了膠合木構(gòu)件的受力全過程，探討了其破壞形態(tài)，研究了尺寸對其抗彎強度的影響。試驗結(jié)果表明：截面平均應(yīng)變分布符合平截面假定；抗彎強度隨著尺寸的增大而降低，具有明顯的尺寸效應(yīng)?；赪eibull脆性斷裂理論模型，得到了落葉松膠合木梁長度與高度的組合尺寸效應(yīng)系數(shù)；提出了一個拉壓本構(gòu)關(guān)系模型；并提出了一種膠合木梁的抗彎承載力計算方法。經(jīng)過與試驗結(jié)果的對比驗證，該方法計算結(jié)果與試驗結(jié)果吻合較好。［關(guān)鍵詞］膠合木梁; 抗彎承載力; 尺寸效應(yīng)系數(shù); 受彎性能; 本構(gòu)模型中圖分類號：TU366.3 文獻標識碼：A 文章編號：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
*國家林業(yè)局公益性行業(yè)科研專項（201304504），國際科技合作與交流專項(2014DFA53120)，湖南省自然科學(xué)基金項目（12JJ5012），湖南省研究生科研創(chuàng)新基金項目（CX2013B351），中南林業(yè)科技大學(xué)研究生科技創(chuàng)新基金（CX2013A05）。作者簡介：周先雁，博士，教授，博士生導(dǎo)師，Email：zxy560805@163.com。
