Kalthoff Winkler Test

Background

This test is used to investigate the modes of failure at a pre-cracked specimen impacted by varying velocities.

Instrumented impact tests are currently used to measure the dynamic fracture toughness KId of materials. During the impact event, the load at the peen of the striking hammer is measured as a function of time or deflection of the specimen. From the critical load for onset of crack propagation the dynamic fracture toughness value KId is derived utilizing the conventional static stress intensity factor formulas (ASTM STP 466 (1970)--Impact Testing of Metals, American Society for Testing and Materials, Philadelphia; ASTM STP 563 (1974)--Instrumented Impact Testing, American Society for Testing and Materials, Philadelphia; IIW (International Institute of Welding, Commission X), U.K. Briefing Group on Dynamic Testing (1976), "Some Proposals for Dynamic Toughness Measurement," Proc. Int. Conf. Dynamic Fracture Toughness, London; PVRC/MPC Joint Task Group on Fracture Toughness Properties for Nuclear Components, Working Group on Instrumented Precracked Charpy Test, Chairman C. Buchalet, Westinghouse Nuclear Energy Systems (1974), "Recommended Procedure for Instrumented Precracked Charpy Testing").