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(1重慶科技學(xué)院建筑工程學(xué)院， 重慶 401331； 2 能源工程力學(xué)與防災(zāi)減災(zāi)重慶市重點實驗室， 重慶 401331)
［摘要］RC框架梁受彎損傷會發(fā)生軸向伸長，周邊構(gòu)件對梁伸長的約束作用會在梁中產(chǎn)生不可低估的軸力，顯著提高其抗彎承載力，此現(xiàn)象未得到足夠重視。RC框架梁抗彎承載力非預(yù)期超強可能導(dǎo)致結(jié)構(gòu)在強震中難以出現(xiàn)預(yù)期的強柱弱梁破壞模式，造成結(jié)構(gòu)倒塌。為研究地震作用下RC框架梁受彎損傷軸向伸長效應(yīng)，首先闡明了梁伸長的概念，并從機理上揭示了梁伸長的必然性及其構(gòu)成，基于試驗研究定性分析了梁伸長規(guī)律；發(fā)現(xiàn)了目前尚缺乏全面綜合考慮梁伸長效應(yīng)的分析模型；歸納分析了梁伸長效應(yīng)對結(jié)構(gòu)抗震性能影響規(guī)律的研究進展及忽略此效應(yīng)可能引發(fā)的問題。最后指出亟待開展考慮梁受彎損傷軸向伸長效應(yīng)的RC框架結(jié)構(gòu)強震破壞模式及抗震性能的系列基礎(chǔ)性研究，為進一步完善框架結(jié)構(gòu)抗震延性設(shè)計方法提供支撐。
［關(guān)鍵詞］梁伸長； 破壞模式； 抗震性能； 數(shù)值模擬； 鋼筋混凝土框架結(jié)構(gòu)
中圖分類號：TU375-1文獻(xiàn)標(biāo)識碼：A文章編號：1002-848X(2019)13-0098-08
Study on axial elongation effect of RC frame beams due to bending damage under earthquake
Wang Liping1,2， Zhang Wei1， Luo Wenwen1,2
(1 Architectural and Civil Engineering Institute, Chongqing University of Science and Technology, Chongqing 401331, China； 2 Chongqing Key Laboratory of Energy Engineering Mechanics & Disaster Prevention and Mitigation, Chongqing 401331, China)
Abstract:The bending damage of RC frame beams leads to axial elongation. The restraint effect of surrounding members on the elongation of beams produces undeniable axial force in the beams, which can significantly improve the flexural capacity of the beams. This phenomenon has not received enough attention. The unexpected super-strength of flexural capacity of RC frame beams may lead to the failure mode of strong columns and weak beams under strong earthquakes, resulting in structural collapse. In order to study the axial elongation effect of RC frame beams subjected to bending damage under earthquakes, the concept of beam elongation was firstly clarified, and the inevitability and composition of beam elongation were revealed from the mechanism. Based on the experimental study, the law of beam elongation was qualitatively analyzed. It was found that there is no comprehensive analysis model considering beam elongation effect at present. The research progress of the influence of beam elongation effect on seismic performance of structures and the possible problems caused by neglecting this effect were summarized and analyzed. Finally, it was pointed out that a series of basic studies on the seismic failure modes and seismic performance of RC frame structures considering the effect of axial elongation of beam flexural damage were urgently needed to provide support for further improving the seismic ductility design method of frame structures. Finally, it was pointed out that a series of basic studies on the strong seismic failure modes and seismic performance of RC frame structures considering the effect of axial elongation of beam flexural damage were urgently needed to provide support for further improving the seismic ductility design method of frame structures.
Keywords:beam elongation; failure mode; seismic performance; numerical simulation; RC frame structure
*國家自然科學(xué)基金項目(51808087)，重慶科技學(xué)院校內(nèi)科研基金項目（CK2016Z14, ck2017zkyb016），重慶市自然科學(xué)基金項目(cstc2018jcyjAX0695, cstc2018jcyjAX0052)。
通訊作者：羅文文，博士，講師， Email: luowenwen326@163.com。
