SEDL / STP / STP1130-EB / STP15514S

Using Small Specimens to Measure Dynamic Fracture Properties of High-Toughness Steels

Conque, H
Senior research engineer and manager, Mechanics of Materials, Southwest Research Institute, San Antonio, TX

Dexter, RJ
Senior research engineer, Advanced Technology for Large Structural Systems, Lehigh University, Bethlehem, PA

Hudak, SJ
Senior research engineer and manager, Mechanics of Materials, Southwest Research Institute, San Antonio, TX

Pages: 13    Published: Jan 1992

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Abstract

The use of coupled pressure bars (CPB) to induce dynamic fracture in tough materials using small specimens is investigated. CPB experiments were performed with a nuclear pressure vessel steel, A533 Grade B Class 1, over the temperature range 37 to 100°C. The dynamic fracture initiation toughness at a stress intensity loading rate, K^I, of 2 × 10⁶ MPa∙m^½ s⁻¹ was deduced from the simulation of the fracture experiment with a dynamic viscoplastic finite-element fracture code. At 100°C, no cleavage fracture was observed for either dynamic crack initiation or subsequent propagation and arrest. A procedure to measure initiation, propagation, and arrest toughnesses of nuclear pressure vessel steels up to service temperature with CPB specimens is introduced.