Robotic testing system with optical strain measurement

Optical strain measurement is becoming increasingly important for tensile tests on metals. The integration of a laser speckle extensometer into a robotic tensile testing system allows the user to benefit from the advantages of both systems – automated testing combined with optical strain measurement.

The testing system comprises a Zwick Z100 testing machine for test loads up to 100 kN and a 6-axis industrial robot which transports the specimens from a magazine (capacity up to 250 specimens) into the testing machine. This operation is performed completely automatically, as is measurement of specimen cross-section. The advantages of the robotic system include high specimen throughput and excellent test-result reproducibility (through elimination of subjective influences such as hand-temperature, off-center/crooked insertion etc.). This results in relatively low test costs per specimen, with the consequence that a robotic testing system pays for itself within approximately two years.

By equipping the testing system with a laserXtens, Zwick combines the advantages of automation with those of optical strain measurement. laserXtens requires no gage marks on the specimen and is indispensable for specimens which react critically to knife-edges or would damage contact-measuring extensometers at specimen break. With a resolution of 0.15 µm it is the ideal choice if very high accuracies at low extensions are required. laserXtens is also suitable for strain-rate control to EN ISO 6892-1 (2009), Method A (closed loop).

More information about robotic testing systems.