Flexure/bend testing is also known as transverse testing or modulus of rupture testing. It is a way of determining the flexural strength, or how something will react, when it is being bent. This is done by supporting the specimen at given points along its length and applying an axial compressive load evenly at one or more points.
Many products are designed to flex and bend, and return to their original state so, for example, sports equipment and tools need to be tested under repeated flexure to ensure required performance.
This type of test is performed to assess the strength of components and materials e.g. PVC/ABS pipes; ceramic or polymer rods and bars; stiff metal wire; rods; tubing; structural panels and beams of wood, metal, composites or concrete. Other applications where testing bending strength is just as critical include 3-point bend testing of hypodermic needles and vascular stents.
Stiffness is a required flexure measure in paper, board or films, and there are industry standards and methods, and special fixtures for these kinds of test under what can be extremely light forces.
There are many standards for flexure/bend testing, developed by organisations such as ASTM, BS, DIN, ISO and MIL. They include: