CAJ | 학술논문

为获得路用水泥混凝土在高应力比作用下其疲劳可靠度的变化规律,首先推导了包括混凝土疲劳寿命在内的单调随机变量的概率密度,然后推导了Miner与Chaboche-Zhao疲劳损伤模型的概率密度.借助室内疲劳试验结果,获得这2种模型的疲劳损伤概率密度函数.最后,将荷载作用次数代入上述函数,从而获得水泥混凝土疲劳可靠度随荷载作用次数的变化规律.结果表明:随着荷载作用次数的增加,相同应力比下,疲劳可靠度从100％逐渐衰减为0％；无论何种应力比,在荷载作用初期,疲劳可靠度均有一个较为稳定的阶段；随着应力比的增加,该稳定阶段逐渐缩短,且可靠度为0％时对应的荷载作用次数也减小；在可靠度衰减阶段,对于相同荷载作用次数,应力比越高,则混凝土可靠度越低；此外,Miner疲劳损伤模型比Chaboche-Zhao疲劳损伤模型偏安全.
위획득로용수니혼응토재고응력비작용하기피로가고도적변화규률,수선추도료포괄혼응토피로수명재내적단조수궤변량적개솔밀도,연후추도료Miner여Chaboche-Zhao피로손상모형적개솔밀도.차조실내피로시험결과,획득저2충모형적피로손상개솔밀도함수.최후,장하재작용차수대입상술함수,종이획득수니혼응토피로가고도수하재작용차수적변화규률.결과표명:수착하재작용차수적증가,상동응력비하,피로가고도종100％축점쇠감위0％；무론하충응력비,재하재작용초기,피로가고도균유일개교위은정적계단；수착응력비적증가,해은정계단축점축단,차가고도위0％시대응적하재작용차수야감소；재가고도쇠감계단,대우상동하재작용차수,응력비월고,칙혼응토가고도월저；차외,Miner피로손상모형비Chaboche-Zhao피로손상모형편안전.
In order to obtain the change law of the fatigue reliability of cement concrete for highway pavement under high stress ratios,first,the probability densities of monotonic random variables including concrete fatigue life are deduced.And then,the fatigue damage probability densities of the Miner and Chaboche-Zhao models are deduced.By virtue of laboratory fatigue test results,the fatigue damage probability density functions of the two models can be obtained,considering different stress ratios.Finally,substituting load cycles into them,the change law of cement concrete fatigue reliability about load cycles can be acquired.The results show that under the same stress ratio,with the increase in the load cycle,the fatigue reliability declines from almost 100％ to 0％ gradually.No matter under what stress ratio,during the initial stage of the load action,there is always a relatively stable phase for fatigue reliability.With the increase in the stress ratio,the stable phase gradually shortens and the load cycle corresponding to the reliability of 0％ also decreases.In the descent phase of reliability,the higher the stress ratio is,the lower the concrete reliability is for the same load cycle.Besides,compared with the Chaboche-Zhao fatigue damage model,the Miner fatigue damage model is safer.