A microtensile device ~MTD! especially designed to carry out test on nonstandard specimens such as thin wires, polymers, and biological samples is described. The use of a feedback control system in order to apply the load and simultaneously assure axial deformations allows for measurement with great accuracy even on specimens of only a few millimeters. Within the device, a laser interferometer gives high-resolution elongation measurements. The prototype allows for the evaluation of specimen stiffness, defined as the ratio of the applied load versus the specimen axial deformation. This measurement can be performed with an accuracy better than 1.5%, depending on the accuracy class of the load cell and its positioning in the MTD body, while the elongation measurement is affected by a systematic error of 0.1 mm/N proportional to the applied load. In order to compare the obtained results to commonly available data, some tests have been performed on specimens of well-known mechanical characteristics, such as optical fibers. A typical optical fiber Young modulus evaluation was (6761.5) GPa. Other tests have been carried out on nonconventional ~biological! specimens with the aim of demonstrating the MTD specific application field.
Micro Tensile Device for stress - elongation tests on non standard specimens / F., Branca; Marinozzi, Franco. - In: REVIEW OF SCIENTIFIC INSTRUMENTS. - ISSN 0034-6748. - 71:(2000), pp. 2526-2531.
Micro Tensile Device for stress - elongation tests on non standard specimens
MARINOZZI, Franco
2000
Abstract
A microtensile device ~MTD! especially designed to carry out test on nonstandard specimens such as thin wires, polymers, and biological samples is described. The use of a feedback control system in order to apply the load and simultaneously assure axial deformations allows for measurement with great accuracy even on specimens of only a few millimeters. Within the device, a laser interferometer gives high-resolution elongation measurements. The prototype allows for the evaluation of specimen stiffness, defined as the ratio of the applied load versus the specimen axial deformation. This measurement can be performed with an accuracy better than 1.5%, depending on the accuracy class of the load cell and its positioning in the MTD body, while the elongation measurement is affected by a systematic error of 0.1 mm/N proportional to the applied load. In order to compare the obtained results to commonly available data, some tests have been performed on specimens of well-known mechanical characteristics, such as optical fibers. A typical optical fiber Young modulus evaluation was (6761.5) GPa. Other tests have been carried out on nonconventional ~biological! specimens with the aim of demonstrating the MTD specific application field.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.