ASTM E1820 is a standard test method that is used to determine the fracture toughness of metallic materials using the essential work of fracture (EWF) method. This method is widely used in the aerospace, automotive, and materials industries to evaluate the performance and reliability of metallic materials under various loading conditions.
Fracture toughness is an important property of metallic materials that measures their resistance to crack propagation. The essential work of fracture (EWF) method used in E1820 provides an effective way to measure this property by measuring the amount of energy required to propagate a crack in a material.
ASTM E1820 Test Method
The test method ASTM E1820 involves creating a crack in a metallic sample and measuring the amount of energy required to propagate the crack. The test is typically performed using a standard compact tension (CT) specimen, which is a flat plate with a centrally located crack. The test consists of several steps, as outlined below:
| Applying Load | The testing procedure involves applying a load to the specimen and measuring the amount of energy required to propagate the crack. The load is applied using a specialized machine that can apply both tensile and compressive loads. The load is applied in a controlled manner to ensure that the crack propagates in a stable manner. |
| Measurement of Essential Work of Fracture (EWF) | The measurement of essential work of fracture (EWF) involves measuring the amount of energy required to propagate the crack in the specimen. The energy required to propagate the crack is calculated by measuring the force required to load the specimen and the displacement of the crack during loading. The essential work of fracture is then calculated using the formula provided in the standard. |
