基于损伤理论的预应力混凝土冻融破坏研究

损伤力学提供了一种分析疲劳演化、估算疲劳寿命的有效方法.混凝土冻融破坏是一种低周疲劳损伤,可以利用损伤力学理论进行分析.试验利用损伤力学中疲劳损伤的基本原理对预应力混凝土在冻融循环作用下的损伤与失效过程进行了分析,在比较几种低周疲劳损伤理论的基础上,利用混凝土冻融前后动弹性模量变化的规律建立了预应力混凝土冻融破坏模型.并根据试验结果对模型进行了评价.结果表明在相同冻融循环次数下,随着应力水平的提高,混凝土抗冻能力是提高的;随着冻融的继续进行,应变趋向于定值,此时混凝土不再能承受应力作用而失效破坏.

The research of freeze-thaw damage of prestressed concrete based on damage mechanics

The damage mechanics provides an analysis of the evolution of fatigue damage and an effective way to estimate fatigue life.Concrete's freeze-thaw damage is a low-cycle fatigue damage of injury,damage mechanics theory can be used for analysis.The fatigue damage in prestressed concrete's freeze-thaw cycle of injury and failure process are analysised,in several relatively low-cycle fatigue theory based on the use of concrete before and after cryopreservation dynamic elastic modulus change the law to establish a model of prestressed concrete freeze-thaw damage.Based on the experimental results and the evaluation of the model.The results show that with the stress level and the same times of freeze-thaw,the ability of concrete's antifreeze is improving;With the continuation of freezing and thawing,strain tends to a fixed value,concrete can no longer sustain the stress and time of failure.