AbstractThe objective of this work was to test modifications of an autographic impact device which would make autographic impact testing more suitable for routine work. Autographic impact devices allow the force transmitted to a specimen during impact to be recorded and displayed; thus, a detailed analysis of the impact process is possible. In addition to the measurement of the breaking energy, information on the load at which yielding begins and how the impact energy is absorbed by the specimen during impact can be obtained. Through the use of autographic impact devices, the impact resistance of plastics during an impact test has been shown to be composed of three basic areas of contribution: (1) an elastic deformation stage, (2) a plastic deformation stage, and (3) a tearing stage. The autographic method is not practical for routine evaluations because of the excessive time and effort necessary to set up, calibrate, and interpret each test. The following modifications of the autographic device were made to improve the efficiency of the method: (1) improved triggering technique, (2) improved calibration procedure, (3) elimination of the preloading force, and (4) a computer program to analyze the data much more efficiently. It is expected that these modifications will allow autographic tests to be performed efficiently.
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