OPTICAL STRAIN TESTING OF LASER-JOINED SHEET STEELS

H. Haferkamp(1), M. Niemeyer(1), F. v. Alvensleben(2), M. Goede(2), C. Schmid(2), M. Höfemann(1), A. Bormann(2)

(1) University of Hannover, Germany; (2) Laser Zentrum Hannover, Germany

In order to investigate the progression of tensile strength at the joints of a laser beam welded sheet metal, the results of an laser optical measurement procedure applied during a tension test are being utilised. With the aid of a laser speckle interferometer and an interpretation software of the diagrams, the extension of the samples may be observed during the tension test. This measuring device allows the investigation of its elastic an plastic behaviour and the local tensile strength in the area of the joint including the heat affected zone. It is our intention to identify the properties of the sheet metal joints, which may serve as an aid for optimising future production processes and characteristic features.

Keywords: laser, sheets, speckle, extension