What is Flexural Strength?
Flexural strength, also called bending strength, is a material’s ability to resist deformation or failure when subjected to a bending load.
It measures how well a material can withstand forces that cause it to bend before it cracks, fractures, or breaks.
Why is it Important?
The flexural strength test is used to evaluate materials that experience bending forces during service.
The Test Helps Determine:
- Resistance to bending loads
- Structural performance
- Material toughness
- Ability to withstand combined tensile and compressive stresses
Flexural strength is particularly important for coatings, composites, plastics, repair materials, and structural components.
How is the Test Performed?
- A test specimen with standardized dimensions is prepared.
- The specimen is supported at two points.
- A load is applied at the center (three-point bending) or at two loading points (four-point bending).
- The load is increased at a controlled rate.
- The test continues until the specimen fractures or reaches a specified deformation.
What Happens During the Test?
As the specimen bends:
- The top surface experiences compressive stress.
- The bottom surface experiences tensile stress.
Failure usually occurs on the side subjected to the highest tensile stress.
What Does the Result Mean?
Flexural Strength is the maximum stress developed in the specimen just before failure.
The result is typically reported in:
- MPa (Megapascals)
- psi (Pounds per Square Inch)
A higher flexural strength value indicates that the material can withstand greater bending forces before breaking.
Example
If Material A has a flexural strength of 120 MPa and Material B has a flexural strength of 80 MPa, Material A can resist higher bending loads before failure.
Summary
ASTM D790 is a bending test used to measure a material’s flexural strength and flexural properties. A specimen is supported at each end and loaded until it fails. The test indicates how well a material resists bending forces and provides an important measure of its structural performance.
Source: Chesterton ARC Manuals, astm.org
Please note:
Despite thorough research, our description may contain inaccuracies regarding the most current ASTM procedures.
Our description should be considered solely as an overview for informational purposes.