摘要
采用声发射平均频率和相对能量以及幅值识别了3D C/SiC复合材料的拉伸损伤模式,探讨了拉伸加卸载过程中材料的费利西蒂(Felicity)效应。通过分析具有不同拉伸性能试样的损伤过程,研究了不同损伤模式的时间分布特征对材料拉伸性能的影响关系。分析结果表明,3D C/SiC复合材料中基本不存在凯瑟(Kaiser)效应,Felicity比随着应力水平的升高而降低,相对应力水平高于65%时出现突降。3D C/SiC复合材料高性能的决定性因素不是声发射波击总数,而是高幅高能量信号发生的时间和次数。在加载前期(应变<0.15%)损伤较少是材料高强度的必要条件,纤维簇断裂在加载中后期的分散分布有利于提高拉伸强度。
The various damage mechanisms in 3D C/SiC composites were identified using acoustic emission（AE） signal parameters,and the Felicity effect was studied with tensile loading-unloading procedure.The effect of damage characterization on tensile behavior was investigated.As a result,the Kaiser effect is almost absent and the Felicity ratio decreases with the increase of the stress level and drops when the relative stress ratio is above 65%.The key factor of high performance of 3D C/SiC composite is not the amount of all AE hits but the time and quantity of major signals with higher energy and amplitude.The lower damage quantity is necessary to improv tensile strength of the composite during smaller deformation stage（strain0.15%）.The fiber cluster failure dispersion on bigger deformation stage is benificial to the enhancement of the tensile strength.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2010年第6期82-87,共6页
Acta Materiae Compositae Sinica
基金
国家自然科学基金项目(90405015
90815001
10902025)
中国博士后科学基金(20090460839)
