摘要
computer controled procedure is developed for automatic measurementsof the crack opening stress Sop dunng fatigue tests. A crack opening displacement gauge(COD meter) is used to obtain digital data on the load-COD curves. Three methods forderiving S op from the data sets are compared:(1) slope method, (2) tangent lines inter-secting method, and (3) tangent point method. The effect of the position of the CODmeter with respect to the crack tip on Sop is studied in tests of 2024-T3 specimens. Re-sults of crack growth and Sop are presented for CA loading with an overload and withan overload followed by an underload.
computer controled procedure is developed for automatic measurementsof the crack opening stress Sop dunng fatigue tests. A crack opening displacement gauge(COD meter) is used to obtain digital data on the load-COD curves. Three methods forderiving S op from the data sets are compared:(1) slope method, (2) tangent lines inter-secting method, and (3) tangent point method. The effect of the position of the CODmeter with respect to the crack tip on Sop is studied in tests of 2024-T3 specimens. Re-sults of crack growth and Sop are presented for CA loading with an overload and withan overload followed by an underload.
