Significance and Use
5.1 Instrumented impact testing provides an independent measurement of the absorbed energy associated with fracturing CVN or MCVN specimens for test machines equipped with a dial or optical encoder, or both.
5.2 Instrumented impact testing is particularly effective in MCVN testing since the resolution of a calibrated strain-gaged striker does not necessarily decrease with the magnitude of the measured force.
5.3 In addition to providing a measure of instrumented absorbed energy (Wt), instrumented testing enables the determination of characteristic force, partial instrumented absorbed energy, and displacement parameters. Depending on the material and test temperature, these parameters can provide very useful information (in addition to instrumented absorbed energy) on the fracture behavior of materials such as: the temperature which corresponds to the onset of the lower shelf; the temperature which corresponds to the onset of the upper shelf; partial instrumented absorbed energy up to the maximum force (Wm); partial instrumented absorbed energy up to the force at brittle fracture initiation (Wbf); the partial instrumented absorbed energy after the maximun force (Wt–Wm); the general yield force (Fgy); the force at brittle fracture initiation (Fbf); the arrest force (Fa). The instrumented data may also be used to highlight test results which should be discarded on the basis of misalignment or other critical test factors.
1.1 This test method establishes the requirements for performing instrumented Charpy V-notch (CVN) and instrumented miniaturized Charpy V-notch (MCVN) impact tests on metallic materials. This method, which is based on experience developed testing steels, provides further information (in addition to the absorbed energy) on the fracture behavior of the tested materials. Minimum requirements are given for measurement and recording equipment such that similar sensitivity and comparable absorbed energy measurements to those obtained in Test Methods and are achieved.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.