engleski

ANALYSIS OF COMPLIANCE FOR EVALUATION OF INSTRUMENTED IMPACT TEST DATA

Unlike static tensile testing machines, the stiffness determination of Charpy impact machines is more complex and there is still no described method for precise determination. Since the foundation and the way of connection between machine and foundation have influence on the values of energy and forces during testing, it is necessary to determine the stiffness for every installed machine. Reliable method to review the stiffness is carried out by using the CRM (Certified Reference Materials) samples where deviation from the specified value of energy is a good indicator for machine stiffness. During direct calibration of the pendulum impact tester with CRM samples, the measuring uncertainty (as a measuring result) includes all known factors that have influance on the energy loss. Compliance, the reciprocal value of stiffness, is a measure for the deformation under the applied load. Donald R. Ireland had developed methods in his work to evaluate the compliance. In this paper evaluation of compliance of the instrumented RKP 450 Zwick/Roell impact machine is described. For the purpose of evaluation, CRM samples of 70 J from IfEP GmbH (Institut für Eignungsprüfung) were used. Forces from the instrumented force – displacement diagram were evaluated as well.

compliance, instrumented impact testing, force

nije evidentirano