局部高密度钢纤维混凝土弯曲疲劳损伤演变规律  

DAMAGE AND ITS EVOLUTION FOR PARTIALLY HIGH PERCENTAGEFIBER REINFORCED CONCRETE UNDER FLEXURAL FATIGUE

作　　者：易成[1] 沈世钊[2] 谢和平[1] 

机构地区：[1]中国矿业大学北京校区岩石力学与分形研究所,北京100083 [2]哈尔滨工业大学建筑工程学院,黑龙江哈尔滨150006

出　　处：《工程力学》2002年第5期1-6,共6页Engineering Mechanics

基　　金：国家自然科学基金(19702021);2000年度高等院校博士点学科专项科研基金;广州市建委科学研究基金资助项目

摘　　要：在混凝土弯曲构件底部用高密度钢纤维局部增强称为局部高密度钢纤维混凝土(PHPFRC)与同样纤维掺量的传统钢纤维混凝土(SFRC)比较它可以用相近的价格获得高得多的刚度﹑承载力和抗疲劳断裂性能为了能够预测PHPFRC在循环荷载作用下的疲劳寿命需要确定其疲劳损伤演变规律本文通过试验发现局部高密度钢纤维混凝土的弯曲疲劳损伤表现出韧性材料所具有的性质基本上接近韧性损伤这与素混凝土及传统钢纤维混凝土有本质的不同根据其疲劳特性的实验结果探讨了PHPFRC弯曲疲劳损伤阈值结合损伤理论建立了适合于纤维体积掺量为1.Partially High Percentage Fiber Reinforced Concrete (PHPFRC) is a kind of fiber concrete in which fibers are concentrated with high density in the tension region of component under bending. PHPFRC possesses much higher load bearing capacity, rigidity, fatigue and fracture properties than conventional steel fiber reinforced concrete (SFRC), but its cost is similar to that of SFRC. The fatigue damage evolution rule for PHPFRC is proposed to predict its fatigue life under multi-amplitude cycle load. It was observed that the fatigue damage of PHPFRC is tough damage from test results, being different from plain concrete and most SFRC. Based on the continuum damage mechanics and fatigue behavior of the specimens, damage variable D for fatigue of PHPFRC is defined, and the elementary form of damage evolution function is determined. For the specimens in which average fiber volume fraction is 1.2%, the function parameters are given according to the test results.

关 键 词：钢纤维混凝土 弯曲 疲劳损伤 演变规律 韧性损伤 阈值 等幅疲劳实验 

分 类 号：TU528.572[建筑科学—建筑技术科学]