2024T3铝板试件疲劳裂纹张开应力测量

FATIGUE CRACK CLOSURE MEASUREMENTS ON 2024T3SHEET SPECIMENS

建立了一种用裂纹张开位移引伸计对２０２４Ｔ３铝板试件的疲劳裂纹张开应力进行自动测量的方法。比较了斜率法、切线相交法和切点法所得结果的差别及测点位置的影响。并给出了超载作用下的疲劳裂纹张开应力的测量结果。

A computer controlled procedure is developed for automatic measurements of the crack opening stress Sop during fatigue tests A crack opening displacement gauge(CODmeter)is used to obtain digital data on load COD curves. Three methods for deriving Sop from the da- ta sets are compared:(1) slope method,(2)tangent lines intersection method,and(3)tangent point method. The effect of the position of the COD meter with respect to the crack tip is studied in tests on 2024T3 specimens. Results on crack growth and Sop are presented for CA loading with an overload and with an overload followed bv an underload.