Crack Paths 2012

b)

12500 cycles

a)

Figure 3. Crack shape at interrupted tests with = 211 MPa.

Figure 4. Cracks found in interrupted tests with = 211 MPa.

The tests were run until failure, but also several tests at 211 M P awere interrupted

before failure. Someof these specimens were sectioned and polished to look for cracks

with the microscope. The test interrupted at 5000 cycles (19% of total life) showed no

1037