Tension - Torsion Testing

Tension – Torsion Testing

Torsion testing allows the determination of shear properties in a material. Torsion testing twists a specimen to a specified degree, with a specified force, or until the material fractures. This when combined with tensile testing (either as a combined application of tension and torsion, or sequentially) allows a number of engineering behaviours to be explored that cannot be achieved with uniaxial testing alone.
The test can also be performed under fatigue conditions
and at elevated temperature. SMaRT has the capability
to carry out such testing at loads of up to 50kN in both
tension and torsion and at temperatures up to 900C.

The purpose of a torsion test is to determine sample behaviour when twisted, or under torsional forces, as a result of applied moments that cause shear stress about the axis. Measurable values include: the modulus of elasticity in shear, yield shear strength, torsional fatigue life, ductility, ultimate shear strength, and modulus of rupture in shear. These values are dissimilar to those measured by an axial tensile test and are important in manufacturing as they may be used to simulate the service conditions, check the product’s quality and design, and ensure correct manufacture.

SMaRT routinely conducts torsion testing in compliance with the following international and industry standards (working to other methods are available upon request):

ISO 1352 Metallic materials – Torque-controlled fatigue testing
ASTM E2207 Standard practise for strain-controlled axial-torsional fatigue testing of thin-walled tubular specimens