| 摘要: |
| 为探究橡胶水泥基材料的疲劳及损伤演化特性，以橡胶水泥砂浆为研究对象，对其分别进行10、20、30 kN荷载等级下的10次（低次/限次）等荷循环加-卸载试验，并对试件产生的加载应变、加载应变差、累积残余应变、累积残余应变差、不闭合度、累积残余应变损伤（塑性损伤），以及加载和卸载变形模量进行分析.结果表明：试件的加载应变和累积残余应变均随着循环荷载等级的增大而增大；试件的加载应变差和累积残余应变差随着循环次数的增加以互相交错波动的形式逐渐减小至0附近；随着循环次数的增加，试件的不闭合度减小，塑性损伤增大，且两者均随循环荷载等级增大而增大；试件的加载和卸载变形模量随着循环次数的增加以分段线性波动的形式增大，也随着循环荷载等级的增大而增大.同时建立了基于临界塑性损伤假定条件下的塑性损伤模型和刚度变化模型，对试件在高次/不限次等荷循环加-卸载过程中的疲劳塑性损伤和刚度演化特征进行了初步预测和表征. |
| 关键词: 橡胶水泥砂浆 循环加-卸载 循环荷载等级 不闭合度 塑性损伤 |
| DOI：10.3969/j.issn.1007-9629.2021.05.009 |
| 分类号:TB332 |
| 基金项目:国家自然科学基金资助项目（52008003、52074009）；安徽省重点研究与开发项目（201904a07020081） |
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| Fatigue and Damage Evolution Characteristics of Rubber Cement Mortar under Graded Constant Load Cyclic Compression |
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YANG Rongzhou, XU Ying, ZHENG Qiangqian, CHEN Peiyuan, WANG Jia
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School of Civil Engineering and Architecture， Anhui University of Science and Technology， Huainan 232001， China
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| Abstract: |
| To explore the fatigue and damage evolution characteristics of rubber cement-based materials， 10 （low/finite cycles） equal load cyclic loading-unloading cycle tests were carried out on rubber cement mortar under 10，20，30 kN load grades respectively. The loading strain， the loading strain difference， the cumulative residual strain， the cumulative residual strain difference， the degree of non-closure， the cumulative residual strain damage （plastic damage）， and the modulus of deformation under loading and unloading were analyzed. The results show that both the loading strain and the cumulative residual strain increase with the increase of the cyclic load grade， and the loading strain difference and the cumulative residual strain difference gradually decrease to about 0 with the increase of the number of cycles. With the increase of the number of cycles， the degree of non-closure decreases， and the plastic damage increases， and both the degree of non-closure and plastic damage increase with the increase of the cyclic load grade. The deformation modulus of loading and unloading increases in the form of piecewise linear fluctuation with the increase of the number of cycles， and also increases with the increase of the cyclic load grade. Finally， both the plastic damage model and stiffness change model based on critical plastic damage assumption were established to predict the fatigue plastic damage and stiffness evolution characteristics of specimens in the process of loading-unloading with high/unlimited cycles. |
| Key words: rubber cement mortar cyclic loading-unloading cyclic load grade degree of non-closure plastic damage |
