These histories were used to test the Phase II material from the hardened
shaft round robin program.
Test Specimen: (J.Bonnen PhD thesis)
Strain History (repeated): (J.Bonnen PhD thesis)
As indicated in the figure above each test consists of a single
large overload/strain cycle followed by a number of smaller cycles which
share the same maximum strain as the overload cycle.
A block of cycles refers to one overload cycle plus eta small
cycles. In the tests the block was repeatedly applied until
the specimen failed or was deemed a "runout".
sc_amp ol_amp eta Small_Cyc Overload_Cyc No.SmallCycles strainAmpl. StrainAmpl. between overloads
Test 1 : 0.00235 0.00475 50 Test 2 : 0.002 0.00475 100 Test 3 : 0.00167 0.00475 100 Test 4 : 0.00125 0.00475 250 Test 5 : 0.00125 0.0065 250 Test 6 : 0.001 0.00475 500 Test 7 : 0.0009 0.00475 500 Test 8 : 0.00085 0.00462 5000 Test 9 : 0.00082 0.00475 1000 Test 10 : 0.0008 0.00475 1000 Test 11 : 0.0008 0.00462 5000 Test 12 : 0.00075 0.00462 10000 Test 13 : 0.0007 0.0045 20000
We hope that many people will try to predict the fatigue lives of these
specimens. You can find the constant amplitude material properties below.