路用水泥混凝土疲劳损伤的可靠度分析

发布时间：2018-05-24 21:02

本文选题：水泥混凝土 + 疲劳损伤　；参考：《建筑材料学报》2014年06期

【摘要】：为获得路用水泥混凝土在高应力比作用下疲劳可靠度的变化规律,首先推导了水泥混凝土疲劳寿命等单调随机变量的概率密度,然后推导了Miner,Chaboche-Zhao和修正Chaboche-Zhao疲劳损伤模型的损伤概率密度;借助疲劳试验结果,获得这3种模型的疲劳损伤概率密度函数,最后将荷载循环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循环作用次数的变化规律.结果表明:随着荷载循环作用次数增加,相同应力比下,疲劳可靠度从几乎为100%逐渐衰减为0%;无论何种应力比,在荷载循环作用初期,疲劳可靠度均有一个较稳定阶段,但随着应力比的增加,该阶段逐渐减小,且可靠度为0%时对应的荷载循环作用次数也减小;在可靠度衰减阶段,对于相同荷载循环作用次数,应力比越高,则可靠度越低;此外,Miner疲劳损伤模型比修正Chaboche-Zhao疲劳损伤模型偏安全.
[Abstract]:In order to obtain the variation rule of fatigue reliability of road cement concrete under the action of high stress ratio, the probability density of monotone random variables such as fatigue life of cement concrete is first deduced. Then the damage probability density of the Chaboche-Zhao fatigue damage model is derived, and the fatigue damage probability density function of the three models is obtained by using the fatigue test results. Finally, the load cycle times are substituted into the above function. Thus, the variation of fatigue reliability of cement concrete with the number of cyclic loads is obtained. The results show that the fatigue reliability decreases from almost 100% to 0 at the same stress ratio with the increase of the number of load cycles, regardless of the stress ratio, there is a relatively stable stage of fatigue reliability at the initial stage of load cycle. However, with the increase of the stress ratio, the stress ratio decreases gradually, and the number of load cycles corresponding to the reliability is reduced when the reliability is 0, and in the reliability attenuation stage, the higher the stress ratio is, the lower the reliability is. In addition, the Miner fatigue damage model is safer than the modified Chaboche-Zhao fatigue damage model.
【作者单位】：镇江市交通运输局;镇江市公路管理处;
【基金】：国家自然科学基金资助项目(51008071) 江苏省自然科学基金资助项目(BK2010413)
【分类号】：U414

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