Pendulum Impact Tester for Metal Specimens

Operating Principle of a Pendulum Impact Tester

The name "pendulum impact tester" is self explanatory for the function of the machine. A lifted mass has potential energy. This is converted to kinetic energy by the mass being subjected to a free fall. Binding the mass to a fixed pivot (pendulum) deflects the velocity vector. Impact loading of a material being tested is realized at the point of maximum kinetic energy (equal to the minimum potential energy) of the mass. This takes the form of a "flexure test".

This pendulum impact tester is used for examining the break behavior of metallic materials at impact loading. A suitable standardized specimen is loaded in the flexure test until it is completely broken. The work required is measured and is known as the energy absorbed A_V. The term "notched impact strength" a_K is often used, which refers to the energy absorbed A_V on specimen cross-section S; it is measured in j/cm². However, modern test methods examine the functions of the energy absorbed or the flexural force in time and/or travel (deformation of the specimen). Since thermal energy influences the notched bar impact test to a high degree, this method always depends on the temperature of the specimen. This becomes increasingly important if the temperature deviates from ambient temperature through the use of temperature conditioning devices.