Flexural Bend Testing: 3, 4 Point & Micro Bend Test

Flexural bend testing uses bending, flexural stress and flexural strain to determine a materials elasticity and its ability resist deformation under load.

Different bend methods, including 3 point, 4 point and micro-bend result in differing stress distributions.

3 point and 4 point bend test is used for general materials testing and can be applied to organic substrates (PCB laminates for example) to measure rigidity and flexural strength.

The 3 point flexure fixture produces its peak stress at the specimen mid-point with reduced stress elsewhere. This stress localisation is ideal for testing for specific isolation of stress on a component or material.

The 4 point flexure fixture produces peak stresses along an extended region of the specimen hence exposing a larger length of the specimen with more potential for defects and flaws to be highlighted.

Micro bend solutions are ideal for assessing the impact of defects introduced by dicing or surface grinding on the strength of brittle materials.