Kinetic energy lost by the pendulum striker when a notched specimen fractures, reported in joules after friction corrections per Charpy or Izod methods.
Kinetic energy lost by the pendulum striker when a notched specimen fractures, reported in joules after friction corrections per Charpy or Izod methods.
Formula
KV = E0 − E1
E0 is initial pendulum energy and E1 is residual energy after fracture; ISO 148-1 / ASTM E23 define friction and geometry corrections.
Absorbed energy is the energy dissipated in notch fracture during a pendulum impact test. It is a screening toughness metric for metals and some plastics, not a direct fracture mechanics parameter.
A calibrated pendulum releases from a fixed height, strikes the specimen, and records rise after fracture. Machine software or tables convert angle/height to energy with periodic verification using certified reference specimens.
Report method (Charpy V, Izod), specimen size, and temperature. Sub-size specimens require notation per standard (e.g., KV2 for 10×10 mm Charpy).
Worn strikers, loose anvils, incorrect notch orientation, and neglecting friction calibration bias energy low or high.
Charpy impact test systems and Charpy testing machines for metals — absorbed energy, notch toughness, ISO 148-1 and ASTM E23. Vector designs manual, semi-automatic, and robotic Charpy lines from 300 J to 750 J, including sub-zero Charpy, tailored to your laboratory.
Series: Charpy
Izod impact test systems and Izod testing machines for plastics, polymers, and metals — cantilever notch-bar absorbed energy per ISO 180, ASTM D256, and ASTM E23 Izod methods. Vector configures pendulum impact testers from 5.5 J to 50 J (and higher-energy metals options) to your laboratory.
Series: Izod
Normalize Charpy or Izod absorbed energy to impact toughness aK using ligament area beneath the notch.
Open calculator →Charpy Impact Test
A notched bar is broken by a swinging pendulum striker; absorbed energy KV or KU (joules) characterizes toughness and ductile-to-brittle transition versus temperature.
Izod Impact Test
A notched cantilever specimen is struck on its notched face by a pendulum; absorbed energy reflects toughness with a different stress distribution than Charpy.
Ductile-to-Brittle Transition
Temperature range where ferritic steels shift from high absorbed impact energy (ductile) to low energy (brittle) fracture; mapped with Charpy or Izod energy versus test temperature.
