FLEXURE TEST

The flexure test method measures behavior of materials subjected to simple beam loading.

It is also called a transverse beam test with some materials. Maximum fiber

stress and maximum strain are calculated for increments of load.

Results are plotted in a stress-strain diagram. Flexural strength is defined as the maximum stress in the outermost fiber. Flexural modulus is calculated

from the slope of the stress vs. deflection curve.

Flexural strength -also known as modulus of rupture, bend strength, or

fracture strength, a mechanical parameter for brittle material,

is defined as a material's ability to resist deformation

under load. The flexural strength represents the

highest stress experienced within the material at its

moment of rupture.

Why Perform a Flexure Test?

A flexure test produces tensile stress in the convex side of the specimen and compression stress in the concave side. This creates an area of shear stress along the midline. To ensure the primary failure comes from tensile or compression stress the shear stress must be minimized. This is done

Types of Flexure Tests

1.) Three – Point Flex

The Three point bending flexural test provides values for the modulus of elasticity in bending , flexural stress , flexural strain and the flexural stress-strain response of the material. The main advantage of a three point flexural test is the ease of the specimen preparation and testing. However, this method has also some disadvantages: the results of the testing method are sensitive to specimen and loading geometry and strain rate.

2.) Four – Point Flex

TEST PROCEDURE

Generally, the plastic specimen is placed on a support span and the load is applied to the center by a loading nose that produces three point bending at a specified rate. The basic criterion for the test are the support span; the maximum deflection for the test; and the speed of loading the material. These parameters are based on the thickness of test specimen.

Applications

The flexural strength testers are widely used in different areas like:

Plastic IndustryCeramic IndustryConcrete/Cement IndustryRubber Industry

FLEXURAL TESTING MACHINES