Digital speckle correlation method (DSCM) has been widely used in experimental mechanics to obtain
the surface deformation fields. But one of the challenges in practical applications is how to obtain the
high accuracy with micros-strain at the measurement precision of
με. A double-microscopic of digital
speckle correlation measurement is described in this paper. The design concept for the optical system, for
which double microscope and double CCD is combined to measure micro-displacement in our
experiment. The experiment shown the proposed correlation theory and measurement system method is
sufficient satisfies the security engineering measurement needing.
The internal boundary conditions analytical model of laser heat treatment temperature field calculation results, which is validated by experiment, is used to reconstruct three dimensional temperature field distributions by DELPHI. The different lays temperature field of laser treatment is reality reappeared; it is useful to the research of laser heat treatment.
The experiment of laser heat treatment of workpieces with a sharp board milled to be 90°, 55°, 45° and 35° has been finished to investigate the influences of the sharp board on the temperature field and the heat-affected zone. The spot of laser has been sampled using the thermal paper in two planes of different height h1 and h2, and the power distribution of laser has been simulated numerically. A finite element model of numerical calculation is developed to simulate the transient three-dimensional temperature field, and the shade plot and isotherm can be output in any longitudinal and transverse sections and then the hardened zones are determined. The several cross sections of treated workpieces are chosen to make the metallographical analysis and the comparisons with the numerical results. It has proved that the numerical results are in a good agreement with the experimental data and the sharp boards have a great influence on the temperature and the heat-affected zone when laser approaches to the sharp board of workpiece.