Fracture resistance (J-R) curves are used for elastic-plastic fracture mech
anics analyses. The specimen geometry and the reversed cyclic loading affec
t the fracture resistance (J-R) curve. On the specimen geometry, The effect
s of specimen size, plane size, specimen thickness, side grooving and crack
length were studied. On the reversed cyclic loading, the effects of load r
atio and incremental plastic displacement were studied. The results reveale
d that the J-R curves increased with increasing plane size and decreased wi
th increasing a/ W and the J-R curves decreased with decreasing the load ra
tio and the incremental plastic displacement, respectively.