This paper describes a nonlinear FEA (finite element analysis) framework that examines the impact energy to fracture unnotched Charpy specimens by an oversized, nonstandard pendulum impactor called the BFCM (Bulk Fracture Charpy Machine). The specimens are made from railroad tank car steel, have different thicknesses and interact with impact tups with different sharpness. The FEA employs a Ramberg-Osgood equation for plastic deformations. Progressive damage and failure modeling is applied to predict initiation and evolution of fracture and ultimate material failure. Two types of fracture initiation criterion, the constant equivalent strain criterion and the stress triaxiality dependent equivalent strain criterion, are compared in material modeling. The impact energy needed to fracture a BFCM specimen is calculated from the FEA. Comparisons with the test data show that the FEA results obtained using the stress triaxiality dependent fracture criterion are in excellent agreement with the BFCM test data currently exists to quantify the puncture behaviour of materials. Different material failure criteria are used in conjunction with the nonlinear FEA to simulate the tests and to calculate fracture energy. The criteria are based on the state of stress and strain in the impacted specimen. Moreover, a failure criterion based on stress triaxiality, which is a parameter related to the state of stress, provides excellent agreement with the test data for fracture energy.
Analysis of impact energy to fracture unnotched charpy specimens made from railroad tank car steel
2007
8 Seiten, 15 Bilder, 4 Tabellen, 9 Quellen
Aufsatz (Konferenz)
Englisch
British Library Conference Proceedings | 2007
|Investigation of Energy Absorbed from an Instrumented Charpy Impact on Automotive Specimens
British Library Conference Proceedings | 2012
|Vibration testing of railroad tank car specimens
Tema Archiv | 1982
|Characteristics of Charpy impact tests using C-notch specimens
Tema Archiv | 1984
|Algorithm to measure automatically the ductile/brittle fracture of Charpy test specimens
British Library Online Contents | 2010
|