Simulation And Control Of Laser-Controlled Separation Of Brittle Materials

In order to enable laser-controlled separation of brittle materials to be completed and cutting quality to be improved, a simulation method for the separation process and an iterative scheme for controlling crack propagation were proposed. The transient thermal transfer during laser irradiation was analyzed by employing finite element technique. After the transient temperature field was obtained, the corresponding thermal stresses were calculated as a thermo-elastic plane stress problem, and the induced crack propagation was simulated by a suitable fracture criterion and node release method. The simulation of symmetric separation was carried out by the present method. According to the induced maximum temperature and crack propagation of the plate, the effect of two main parameters, laser power and laser scanning speed, on the separation was investigated, and the range of the two parameters for continuous separating was given. For asymmetric and curved separation, because the actual fracture trajectory deviates from the laser scanning path, an iteration scheme for revising of the latter was developed. In the scheme, the crack propagation along desired path is simulated, then the difference between the desired crack growth direction and that predicted at each increment by the Maximum...