本文關(guān)鍵詞： 混凝土 滯回環(huán) 側(cè)壓比 耗散能 損傷估計模型 損傷演化　出處：《長江科學院院報》2017年11期 　論文類型：期刊論文

【摘要】：采用大型多功能液壓伺服靜動力三軸儀對不同單向恒定側(cè)壓下的混凝土進行應(yīng)變速率為10-4s-1的等應(yīng)變增量循環(huán)加卸載試驗,恒定側(cè)壓為單軸靜態(tài)抗壓強度的0%,5%,10%。研究了不同側(cè)應(yīng)力水平下應(yīng)力-應(yīng)變?nèi)�中滯回環(huán)的變化規(guī)律,分析滯回環(huán)與耗散能的關(guān)系,并構(gòu)建損傷估計模型,最后基于耗散能統(tǒng)計,研究混凝土的損傷特性。得出主要結(jié)論如下:(1)全曲線中滯回環(huán)在卸載初始階段應(yīng)力下降較快而變形恢復很慢,但隨著應(yīng)力的逐漸下降,應(yīng)變恢復才開始加快;(2)在循環(huán)次數(shù)相同時,耗散能隨著側(cè)應(yīng)力的增加而增加,且增加幅度明顯,表明單位耗散能具有明顯的側(cè)應(yīng)力敏感性;(3)建立的雙參數(shù)損傷估計模型,能夠很好地擬合循環(huán)加卸載損傷與累積殘余應(yīng)變的關(guān)系;(4)隨著側(cè)壓比的提高,混凝土損傷發(fā)展速度逐漸減慢,損傷累積的路徑大幅延長。
[Abstract]:A large multifunctional hydraulic servo static and dynamic triaxial instrument was used to test the loading and unloading of concrete under different unidirectional constant lateral pressure at the strain rate of 10 ~ (-4) s ~ (-1). The change of hysteresis loop in the whole stress-strain curve under different lateral stress levels is studied, and the relationship between hysteresis loop and dissipation energy is analyzed. The damage estimation model is constructed, and finally based on dissipative energy statistics. The main conclusions are as follows: 1) in the whole curve, the stress of hysteresis loop decreases rapidly and the deformation recovers slowly at the initial stage of unloading, but with the gradual decrease of stress. The recovery of strain only began to accelerate; 2) at the same number of cycles, the dissipation energy increases with the increase of lateral stress, which indicates that the unit dissipation energy has obvious sensitivity to lateral stress. 3) the two-parameter damage estimation model can fit well the relationship between cyclic loading and unloading damage and cumulative residual strain. 4) with the increase of lateral pressure ratio, the damage development rate of concrete gradually slows down, and the path of damage accumulation is greatly prolonged.
【作者單位】： 三峽大學土木與建筑學院;三峽地區(qū)地質(zhì)災(zāi)害與生態(tài)環(huán)境湖北省協(xié)同創(chuàng)新中心;
【基金】：國家自然科學基金項目(51279092) 三峽大學科研創(chuàng)新項目(CX2015025)
【分類號】：TU528
【正文快照】： 1研究背景混凝土結(jié)構(gòu)在服役期間常處于復雜應(yīng)力作用下,同時還會承受相應(yīng)應(yīng)力的循環(huán)作用,如機場跑道上飛機降落的沖擊、橋涵隧道中車輛的來往、采油平臺下海浪的往復等。研究循環(huán)加卸載作用下的混凝土力學性能與損傷機理更加符合實際工程情況,有利于提高人們對于混凝土建筑物抗

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