- 摘 要
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（1 建發(fā)房地產(chǎn)集團(tuán)有限公司， 廈門 361008； 2 上海市建筑科學(xué)研究院上海市工程結(jié)構(gòu)安全重點(diǎn)實(shí)驗(yàn)室， 上海 200032； 3 東南大學(xué)建筑設(shè)計(jì)研究院有限公司， 南京 210096）
［摘要］通過2組7根膠合木梁三面受火后力學(xué)性能的對比試驗(yàn)，研究了不同表面處理和不同受火時間后膠合木梁的破壞形態(tài)、剩余承載力和應(yīng)變的變化規(guī)律。研究表明，膠合木梁剩余承載力隨受火時間增加而明顯降低，受火20～40min后剩余承載力顯著降低；表面有阻燃涂料處理試件剩余承載力略大于無阻燃涂料處理試件。未受火對比試件和受火后試件跨中截面應(yīng)變分布均符合平截面假定；相同荷載作用下，受火后試件梁底和梁頂?shù)膽?yīng)變均大于未受火對比試件。采用基于ABAQUS二次開發(fā)的木材本構(gòu)模型，能準(zhǔn)確預(yù)測木材內(nèi)部溫度在100℃左右時的平臺段，且距離受火面越遠(yuǎn)平臺段越長；水平和豎向炭化深度模擬值與試驗(yàn)值誤差為8.6%～14.0%，能較準(zhǔn)確地模擬膠合木梁的炭化深度； 膠合木梁受火后剩余承載力模擬值與試驗(yàn)值吻合較好，可用于膠合木梁三面受火后剩余承載力的評估。
［關(guān)鍵詞］木結(jié)構(gòu)； 膠合木梁； 三面受火； 阻燃涂料； 炭化深度； 剩余承載力
中圖分類號：TU352-5， TU366-3文獻(xiàn)標(biāo)識碼：A文章編號：1002-848X(2020)16-0087-07
Experimental study of the mechanical behavior of glulam beams exposed to three-side fire
HU Xiaofeng1, CHEN Lingzhu2, XU Qingfeng2, HAN Chongqing3, LENG Yubing2
(1 C&D Real Estate Corporation Limited, Xiamen 361008, China;2 Shanghai Key Laboratory of Engineering Structure Safety, SRIBS, Shanghai 200032, China;3 Architects & Engineers Co., Ltd. of Southeast University, Nanjing 210096, China)
Abstract:The failure mode, residual bearing capacity and strain of 7 glulam beams in 2 groups after exposed to three-side fire were experimentally studied under different fire retardant coating and exposed time. The results show that the residual bearing capacity of glulam beams decreases obviously with the exposed time increasing from 20 minutes to 40 minutes, and the residual bearing capacity of glulam beams with fire retardant coating is slightly bigger than that of exposed specimens without fire retardant coating. The strain distribution in middle cross-section of unexposed and exposed specimens accord with the plane section assumption. Under the same load, the strain at the top and bottom surface of exposed specimens are bigger than the unexposed specimen. Through the secondary development of wood constitutive model based on software ABAQUS, the phenomena that the temperature of wood had a slow growth platform at around 100℃, and the longer the distance from the exposed surface, the longer the platform was can be accurately predicted. The horizontal and vertical charring depth can be accurately predicted, and the error between simulated and test results were 8.6%~14.0%. The simulated results of residual bearing capacity of glulam beams agree well with the test results. The model can accurately evaluate the residual bearing capacity of glulam beams after exposed to three-side fire.
Keywords:timber structure； glulam beam; exposure to three-side fire; fire retardant coating; charring depth; residual bearing capacity
*國家自然科學(xué)基金（51808339），上海市青年科技啟明星計(jì)劃項(xiàng)目（17QB1403400）。
通訊作者：許清風(fēng)，博士，教授級高級工程師，Email: xuqingfeng73@163.com。
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