| 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-Nf![]() ![]() ）曲线呈现出双线性趋势.基于λ-Nf![]() ![]() 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. |
| 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 |
| DOI：10.3969/j.issn.1007-9629.2025.03.001 |
| 分类号:TU528.58 |
| 基金项目: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） |
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| Flexural Fatigue Deformation and Fatigue Life of HS-SHCC |
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ZHOU Jiajia1, DONG Zehua1, CHEN Benfa1, JING Chuan2, ZHAO Jun3
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1.School of Mechanics and Safety Engineering， Zhengzhou University， Zhengzhou 450001， China;2.State Grid Henan Economic Research Institute， Zhengzhou 450052， China;3.School of Civil Engineering， Zhengzhou University， Zhengzhou 450001， China
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| Abstract: |
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-Nf![]() ![]() curve） of HS-SHCC specimens show a bilinear trend. Based on the obtained λ-Nf![]() ![]() 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. |
| Key words: high strength strain hardening cementitious composite flexual fatigue fatigue deformation fatigue life prediction |
