Quantifying the Brittle Fracture Resistance of ROPS and FOPS Steels

Several heats of ASTM A36 and A572 Grade 42 steels were tested for brittle fracture resistance using Charpy V-notch (CVN), dynamic tear, static and dynamic fracture toughness tests. Sheet steels were characterized by subsize Charpy and double edge notch specimen testing. The effects of strain rate, temperature, section size and notch geometry on toughness were explored. Dynamic fracture toughness (K_Id) tests were conducted on full thickness (12 mm) specimens at strain rates close to those felt by the ROPS in a typical roll over of a large machine, and a CVN-K_Id correlation given by K_Id = 26(CVN)^0.43 was derived.