In the Charpy impact test, the specimen is typically:

Explanation:

Charpy Impact Test

• The Charpy impact test, also known as the Charpy V-notch test, is a standardized high strain-rate test that determines the amount of energy absorbed by a material during fracture. This absorbed energy is a measure of the material's toughness and acts as an indicator of its ability to resist brittle fracture.

Working Principle: In the Charpy impact test, a notched specimen is struck by a swinging pendulum hammer at a fixed speed. The specimen is typically supported at both ends, and the hammer impacts the specimen at the notch. The energy absorbed by the specimen during fracture is measured by the height to which the pendulum rises after breaking the specimen. This energy is directly related to the toughness of the material.

Procedure:

• A rectangular bar specimen, usually with a V-notch or U-notch in the middle, is prepared according to standardized dimensions.
• The specimen is placed horizontally between two supports in the testing machine.
• The pendulum hammer is released from a known height to strike the specimen at the notch.
• The pendulum swings through the specimen, breaking it and rising to a height determined by the energy absorbed during fracture.
• The difference in the height of the pendulum before and after the impact is used to calculate the absorbed energy.