基于直流电压降法的三点弯曲试样疲劳裂纹扩展速率测量方法

发布时间：2018-10-15 11:27

【摘要】：通过有限元分析得到了三点弯曲试样的裂纹长度与电压降及裂纹尖端应力强度因子的关系式,开发了可以在应力强度因子恒定、可控升高和降低的条件下进行疲劳试验的软件,通过编写测试程序的方式连续进行不同载荷、载荷比、频率条件下的疲劳试验,在线测量裂纹扩展速率,且根据裂纹长度扩展情况自动改变测试条件.通过对2种镍铝青铜合金材料疲劳裂纹扩展速率测量,对该方法进行了验证,得到了裂纹扩展速率与应力强度因子关系曲线,并利用Priddle公式和ParisErdogan公式拟合得到了裂纹扩展应力强度因子门槛值等疲劳特征参数.
[Abstract]:The relationship between crack length and voltage drop and stress intensity factor at crack tip of three-point bending specimen is obtained by finite element analysis. A software is developed for fatigue test under the condition of constant stress intensity factor, controllable increasing and decreasing stress intensity factor. Fatigue tests under different load, load ratio and frequency were carried out continuously by writing test program. The crack growth rate was measured online and the test conditions were automatically changed according to the crack length growth. By measuring the fatigue crack growth rate of two kinds of Ni-Al bronze alloy materials, the method is verified, and the curve of the relationship between the crack growth rate and the stress intensity factor is obtained. The fatigue characteristic parameters such as the threshold value of the stress intensity factor of crack propagation are obtained by fitting the Priddle formula and the ParisErdogan formula.
【作者单位】：上海交通大学核科学与工程学院;
【基金】：国家重点基础研究发展规划(973)项目(2014CB046701)资助
【分类号】：TG115.57

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