Enter the mass of the pendulum hammer, acceleration due to gravity, initial height of the pendulum hammer, and the distance the pendulum hammer travels after impact into the calculator to determine the energy absorbed in a Charpy Impact Test.

Charpy Impact Test Formula

The following formula is used to calculate the energy absorbed in a Charpy Impact Test.

E = (m * g * h) - (m * g * d)

Variables:

  • E is the energy absorbed by the material (Joules)
  • m is the mass of the pendulum hammer (kg)
  • g is the acceleration due to gravity (9.81 m/s²)
  • h is the initial height of the pendulum hammer (m)
  • d is the distance the pendulum hammer travels after impact (m)

To calculate the energy absorbed in a Charpy Impact Test, multiply the mass of the pendulum hammer by the acceleration due to gravity and the initial height of the pendulum hammer. Then, subtract the product of the mass of the pendulum hammer, the acceleration due to gravity, and the distance the pendulum hammer travels after impact. The result is the energy absorbed by the material.

What is a Charpy Impact Test?

A Charpy Impact Test is a method used to measure the toughness, or the amount of energy a material can absorb before fracturing, of a material. This is done by striking a notched specimen with a pendulum hammer and measuring the energy absorbed in the break. The test is often used to determine the ductility and notch sensitivity of materials, particularly in the field of metallurgy. It is named after its developer, French scientist Georges Charpy.

How to Calculate Charpy Impact Test?

The following steps outline how to calculate the Charpy Impact Test using the given formula:


  1. First, determine the mass of the pendulum hammer (m) in kilograms (kg).
  2. Next, determine the acceleration due to gravity (g) in meters per second squared (m/s²). Use the value 9.81 m/s².
  3. Next, determine the initial height of the pendulum hammer (h) in meters (m).
  4. Next, determine the distance the pendulum hammer travels after impact (d) in meters (m).
  5. Finally, calculate the energy absorbed by the material (E) using the formula E = (m * g * h) – (m * g * d).

Example Problem:

Use the following variables as an example problem to test your knowledge:

mass of the pendulum hammer (m) = 2 kg

acceleration due to gravity (g) = 9.81 m/s²

initial height of the pendulum hammer (h) = 1.5 m

distance the pendulum hammer travels after impact (d) = 0.8 m