Pendelschlag

Pendelschlag is a term used in materials testing for an impact test that determines the toughness or notch sensitivity of a material by striking a notched specimen with a swinging pendulum hammer. The test, commonly referred to as the pendulum impact test, is used to quantify how much energy a material can absorb before fracturing.

Principle: A pendulum of known mass is released from a fixed height and strikes a notched specimen supported as a beam. The impact absorbs energy from the pendulum; the remaining energy in the pendulum after fracture is measured, or the angle through which the pendulum swings is recorded. The energy absorbed by the specimen, expressed in joules, is the difference between the pendulum’s initial potential energy and its residual energy after breaking the specimen. The result is commonly reported as impact energy, with variants such as Charpy (V-notch) and Izod tests, and in some regions as CVN (Charpy V-notch).

Equipment and procedure: A pendulum impact tester (Pendelschlagapparat) includes a swinging hammer, a defined mass, a release mechanism, supports for the specimen, and a means to measure energy or angular displacement. Specimens are notched to create a stress concentration, typically in standardized sizes and notch geometries. Tests are performed at controlled temperatures to study temperature-dependent behavior, such as the ductile-to-brittle transition in steels.

Applications and interpretation: Pendelschlag tests are widely used in metals engineering for quality control and research to compare toughness and notch sensitivity across materials and heat treatments. They provide a rapid, standardized measure of a material’s resistance to sudden impact and fracture.