APPLICATION OF A LOCALLY OPERATING LASER-SPECKLE STRAIN SENSOR ON TENSILE DEFORMATION OF MINIATURIZED NANOSTRUCTURED SPECIMENS

摘要

We report on a locally operating strain sensor based on laser-speckle techniques for strain measurement during tensile deformation of miniaturized specimens. The novel technique was applied to nanostructured specimens gained from High Pressure Torsion (HPT). The samples have a parallel gauge length of 2.5 mm and a cross section area of 0.6 x 0.6 mm2. Therefore, measurements with conventional strain gauges are not possible. In order to ensure the accuracy of the new sensor, displacement tests of free standing samples were performed. Thereafter, tensile tests of conventional aluminum foils were conducted using the novel strain sensor and a standard optical sensor simultaneously. Finally, stress strain curves of miniaturized HPT specimens were measured, and a high precision of measurement was achieved.