摘要
为了研究三维碳纤维编织体增强碳化硅陶瓷基复合材料(3D C/SiC)在疲劳过程中的损伤演化并建立其电阻变化率(ΔR/R0)随疲劳周次变化的模型,对其进行了应力比为0.1、频率为20 Hz、最大疲劳应力为250、255、260 MPa的拉-拉疲劳试验,通过电阻增量仪器测量了连续3D C/SiC在疲劳中的电阻变化率。实验结果表明,ΔR/R0除首次循环降低外,随着疲劳周次的增加呈缓慢增加、台阶式增加和急剧增加3个阶段。根据损伤力学理论,以ΔR/R0为损伤参量,得到了ΔR/R0随疲劳周次变化的模型,该模型结果与实验结果吻合较好。
In order to investigate the damage evolution of 3-dimensional braided carbon-fiber reinforced SiC matrix composite（3D C/SiC） during fatigue and establish the model of relationship between variation rate of electrical resistance（ΔR/R0） and fatigue cycles,tension-tension fatigue tests of 3D C/SiC were carried out under a maximum stress of 250,255,260 MPa,a sinusoidal loading frequency of 20 Hz,a stress ratio of 0.1.ΔR/R0 was measured by electrical resistance appearance.The experimental results show that its ΔR/R0 decreases at the first cycle and then monotonic increases with the increase of fatigue cycles,which mainly consist of steady increases,spurting and abrupt increases.Finally,based on the damage mechanics theory,ΔR/R0 is selected as the fatigue damage variable,and the relationship between ΔR/R0 and fatigue cycles was obtained,the modeling results have good agreement with the experimental results.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2011年第2期165-169,共5页
Acta Materiae Compositae Sinica
