flexure test
TRANSCRIPT
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