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(南京林業(yè)大學(xué)土木工程學(xué)院， 南京 210037)

［摘要］為研究平壓毛竹集成材單軸拉壓狀態(tài)下的應(yīng)力-應(yīng)變本構(gòu)關(guān)系，以5年生毛竹的根部、中部和稍部為原料按照1∶1∶1的比例制備的毛竹集成材試件為研究對(duì)象。探討了毛竹集成材受拉和受壓狀態(tài)下的破壞模式及應(yīng)力-應(yīng)變?nèi)^(guò)程曲線。研究結(jié)果表明：毛竹集成材的受拉破壞表現(xiàn)出典型的脆性拉斷破壞； 毛竹集成材的受壓破壞屬于延性破壞，具體表現(xiàn)3種典型破壞模式：纖維縱向撕裂、竹片層間開裂和褶皺破壞，經(jīng)歷了3個(gè)破壞階段，即線彈性階段、彈塑性階段和加速破壞段。對(duì)于毛竹集成材單軸受拉應(yīng)力-應(yīng)變關(guān)系，提出了線彈性模型； 對(duì)于毛竹集成材單軸受壓應(yīng)力-應(yīng)變關(guān)系，提出了三折線模型和多項(xiàng)式模型，理論模型結(jié)果和試驗(yàn)結(jié)果吻合較好，為毛竹集成材結(jié)構(gòu)有限元分析提供研究基礎(chǔ)。

［關(guān)鍵詞］毛竹集成材； 力學(xué)性能； 破壞機(jī)理； 應(yīng)力-應(yīng)變關(guān)系； 本構(gòu)模型

中圖分類號(hào)：TU366-1文獻(xiàn)標(biāo)識(shí)碼：A文章編號(hào)：1002-848X(2021)02-0135-05

Research on constitutive relationship of flat-pressure laminated moso bamboo lumber for structural application

CHEN Guo, LI Xiang, YU Yunfei, HE Bin, ZHAO Longlong

（College of Civil Engineering, Nanjing Forestry University, Nanjing 210037, China)

Abstract:To study the stress-strain constitutive relationship of the flat-pressure laminated moso bamboo lumber (LBL) under the condition of uniaxial tension and compression, the bottom, middle and top of moso bamboo culms, aged 5 years old, was selected as raw material to fabricate LBL specimen according to the weight ratio of 1∶1∶1 as the research object. The failure mode, stress-strain curve of the whole process of LBL in tension and compression was discussed. The results show that the LBL in tension is featured by brittle failure, while ductile failure for compression. It is observed that there are three main failure modes: longitudinal fiber tearing failure, end cracks and central cracks between bamboo layers, and surface folding. The whole damage process can be divided into three stages, the linear elastic stage, the elastic-plastic stage and accelerated failure stage. For the uniaxial tensile stress-strain relationship of LBL, a linear elastic stress-strain model is suggested. For the uniaxial compressive stress-strain relationship of LBL, the trilinear and polynomial models are proposed, and the results obtained by the theoretic models are in good agreement with experiment results. The results provide a research foundation for the finite element analysis design of LBL structures．

Keywords:laminated moso bamboo lumber; mechanical performance; failure mechanism; stress-strain relationship; constitutive model

*國(guó)家自然科學(xué)基金（51408312），江蘇省自然科學(xué)基金(BK20130982)，江蘇高校優(yōu)勢(shì)學(xué)科建設(shè)工程資助項(xiàng)目（PAPD）。

作者簡(jiǎn)介：陳國(guó)，博士，副教授，Email：chenguo@njfu.edu.cn。