Laser cutting of large-aspect-ratio rectangular blanks in thick sheet metal: Thermal stress analysis

Abstract

The laser cutting of high-aspect-ratio (length to width) rectangular blanks from a thick sheet steel is carried out and the temperature and thermal stress fields in the cut sections are examined. The temperature and stress fields are computed using the finite element model and X-ray diffraction (XRD) is used to measure the residual stress levels in the corners of the cut geometry. A scanning electron microscope equipped with an energy dispersive spectroscopy unit is used to examine the morphological and metallurgical changes in the cut section. It is found that the von Mises stress remains high in the region of the cut surfaces and the predicted values of the residual stress closely agree with experimental results. The micrographs reveal that the cut sections are free from cracks.