疲劳试验中柔度系数的求解方法及影响因素

SOLUTING METHOD OF COMPLIANCE COFFICIENT AND EFFECT FACTORS IN FATIGUE TESTING

在疲劳裂纹扩展速率及断裂力学试验中 ,用柔度法测量疲劳裂纹长度 ,以其方便、快捷、准确而被广泛应用 ,但在腐蚀环境下测量疲劳裂纹长度时 ,测量裂纹尖端张开位移的引伸计 ,即COD(crackopeningdisplacement)规无法直接装卡在标准CT(compacttension)试样上 ,因此设计制作适用于腐蚀环境下的Ⅰ型和Ⅱ型类标准CT试样及其相应的腐蚀疲劳循环装置 ;但由于COD规装卡位置或试样型式的改变 ,必须求出相应的柔度系数才能方便地进行腐蚀环境下的各类试验。通过试验研究 ,建立不同试样型式下柔度系数的求解方法 ,并求出Ⅰ型和Ⅱ型类标准CT试样的柔度系数 ,分析讨论影响柔度系数求解精度的因素 ,通过大量验证试验 。

In fatigue crack growth rate test, the fatigue crack length was measured by compliance method and used extensively because of its being suitable,fast and accurate. But when the fatigue crack length was measured under corrosive circumstance, COD(crack opening displacement) gauge will not be directly used on standard CT(compact tension) sample. Therefore design and prepare the substandard compact tension specimens of two types of Ⅰ and Ⅱ under corrosive circumstance and their corresponding corrosion fatigue cycle apparatus. According to changing of location for COD gauge installed in test sample type,must resolve the compliance coefficient, which can be suitable to carry out the testing. Thus tablished the solution method for compliance coefficient in various test sample types was established and solutioned the compliance coefficient of substandard compact tension specimens of two types of Ⅰ and Ⅱ was formd analysed and discussed the factors of solution precision, can affect the compliance coefficient. A great of testing experiments proved the correction of solution compliance coeffience.