HS‑SHCC弯曲疲劳变形与疲劳寿命  

Flexural Fatigue Deformation and Fatigue Life of HS‑SHCC

作　　者：周甲佳[1] 董泽华 陈本发 景川 赵军[3] ZHOU Jiajia;DONG Zehua;CHEN Benfa;JING Chuan;ZHAO Jun(School of Mechanics and Safety Engineering,Zhengzhou University,Zhengzhou 450001,China;State Grid Henan Economic Research Institute,Zhengzhou 450052,China;School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学力学与安全工程学院,河南郑州450001 [2]国网河南省电力公司经济技术研究院,河南郑州450052 [3]郑州大学土木工程学院,河南郑州450001

出　　处：《建筑材料学报》2025年第3期193-201,共9页Journal of Building Materials

基　　金：国家自然科学基金资助项目(52178257,51708510);河南省优秀青年基金资助项目(222300420082)。

摘　　要：对抗压强度为83.41 MPa的高强应变硬化水泥基复合材料(HS-SHCC)试件进行了四点弯曲疲劳试验,研究了HS-SHCC试件在不同应力水平(0.70、0.80、0.85、0.90)下的裂缝扩展、跨中挠度及疲劳寿命.结果表明:HS-SHCC试件的疲劳寿命随着应力水平的提高而不断减小;HS-SHCC试件在弯曲疲劳荷载下呈现出多裂缝开裂的特征,随着应力水平的降低,试件表面的裂缝数量减少;当应力水平为0.70~0.85时,HS-SHCC试件的跨中挠度呈现出明显的快速发展、稳定发展、失稳三阶段,而当应力水平为0.90时,HS-SHCC试件的跨中挠度则表现出稳定发展和失稳两阶段特性;与普通SHCC相同,HS-SHCC试件的应力水平-疲劳寿命(λ-N_(f))曲线呈现出双线性趋势.基于λ-N_(f)曲线和三参数Weibull分布理论,提出各失效概率下HS-SHCC的弯曲疲劳寿命预测模型,得出失效概率为0.05时HS-SHCC的疲劳强度极限(疲劳循环200万次)对应的最大应力水平为0.618.Four-point bending fatigue tests were carried out on high strength strain hardening cementitious composite(HS-SHCC)specimens with compressive strength of 83.41 MPa.The crack propagation,mid-span deflection and fatigue life of HS-SHCC specimens at different stress levels(0.70、0.80、0.85、0.90)were studied.The results show that the fatigue life of HS-SHCC specimens decreases with the increase of stress level.The HS-SHCC specimens show multi-cracking characteristic under flexural fatigue loads.As the stress level decreases,the crack numbers on the surface of the specimens show a decreased trend.At the stress level 0.70-0.85,the mid-span deflection of HS-SHCC displays obvious three stages of rapid development,stable development and instability.At the stress level 0.90,the mid-span deflection of HS-SHCC specimens shows two stages of stable development and instability.Similar to ordinary SHCC,the stress level-fatigue life curves(λ-N_(f) curve)of HS-SHCC specimens show a bilinear trend.Based on the obtainedλ-N_(f) curve and the three-parameter Weibull distribution theory,a flexural fatigue life prediction model of HS-SHCC under different failure probabilities is proposed.On this basis,the maximum stress level corresponding to the fatigue strength limit(corresponding to 2 million fatigue cycles)of HS-SHCC is predicted to be 0.618 when the failure probability is 0.05.

关 键 词：高强应变硬化水泥基复合材料 弯曲疲劳 疲劳变形 疲劳寿命预测 

分 类 号：TU528.58[建筑科学—建筑技术科学]