Fatigue and fracture behaviour of high strength steel S1100Q

The computational and experimental determination of the fatigue and fracture behaviour of high strength steel S1100Q is presented. Fatigue tests (low-cycle fatigue parameters σf′,εf′, b and c) are carried out in a low cycle regime according to ASTM E 606 standard, where standardised uniform-gage test specimens are used. The fracture mechanics parameters (the coefficient of Paris equation C and m) are determined according to ASTM E 647 standard, where three-point bending specimens are use. Based on low-cycle fatigue parameters the computational analysis is performed to determine the number of stress cycles required for fatigue crack initiation. The remain service life up to the final failure can than be determined using the known parameters C and m and calculated stress intensity factor for treated machine part or structure.The computational model has been used to determine the service life of counterweight bar, which is also experimentally tested. Comparison of computational and experimental results shows a reasonable agreement.