4 point bending test. describe the stresses and moments. what happens at fracture. where and how will it fail.

Question

Accepted Answer

In a 4 point bending test, the stresses and moments are described, along with the failure and fracture behavior.

In a 4 point bending test, a beam is subjected to bending forces at two points and supported at two other points.
The stresses in the beam are highest at the top and bottom surfaces, resulting in tension and compression.
The moments in the beam are highest at the points of loading and decrease towards the supports.
At fracture, the beam fails due to excessive tensile stress or a combination of tensile and shear stress.
Failure can occur at the center of the beam where the stress is highest or at any other point with critical stress concentration.

Accepted Answer

Engineering stress is calculated by dividing the applied force (load) by the original cross-sectional area of the specimen before any deformation occurs.

Actual stress, also known as true stress, takes into account the change in cross-sectional area of the specimen as it deforms under the applied force.

4 point bending test. describe the stresses and moments. what happens at fracture. where and how will it fail.

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