Applications for bending devices and folding devices:

• Determination of material properties of brittle composites, ceramics, metals, wooden panels, rigid plastics 
• Analysis of welded sheets

For the selection of a bending device, various criteria have to be considered based on the test procedures and the standard specification:

• Procedure: 3-point or 4-point bending test or folding test
• Rigid, rotatable or tiltable bending fin and supports
• Dimensions & spacing of supports and fin
• Material, hardness
• Maximum bending force
• Accuracy of deflection
• Possible risks in case of breakage

Bending test and folding test methods

3-point bending test

• Simple test set-up for a variety of test methods
• Especially used for elastic materials

Folding test

• Deformation always up to the plastic range

4-point bending test

• Constant bending moment between both support points (shear force-free area)
• Used mainly to determine the flexural modulus of elasticity of brittle materials.

Options for the supports and bending fins of bending devices

• Bearing can be swivelled, tilted and fixed → Purpose: avoidance of transverse loads with non-symmetrical specimens
• Different bearing surfaces and radii at the bending edges

Bearing distances

• Mostly specified by test standard / specimen dimensions.
• The adjustment of the support distances is carried out either via screws or via a crank. The distances can be read off with millimetre precision using an applied scale.

Determination of the deflection in bending tests

Measuring probe/control probe

• For accurate measurement of deflection

Support with angle sensors

• Direct determination of the bending angle via angle sensors on both supports, e.g. according to DIN EN 12814-1

Safety equipment for bending devices

• Safety enclosure of the bending device: especially for testing ceramics
• Safety door over the entire test area