Yield-Before-Break Fracture Mechanics Analysis og High Strength Steel Pressure Vehicles
Abstract:
Case study examples of fracture mechanics testing and analysis of Ni- Cr-Mo high strength steel cannon tubes are presented. The testing and analysis include significant plastic deformation accompanying fracture, which often occurs when high pressure is applied to high toughness steel pressure vessels. The analysis is based on a comparison of the size of the Irwin crack-tip plastic zone with the remaining ligament of the tube in the critical fatigue crack area that cause final failure. The results of the study show that the type of final failure can be predicted as either a relatively safe yield-before-break failure or a less safe running-crack type of failure for a variety of material, configuration, and loading conditions. Pressure vessels, Fracture mechanics, High strength steel, Plastic yielding, Fatigue failure.