Methods for Determination of Residual Stress of a Formed Plate Using Laser Ablation, Wire EDM and Milling


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In this work laser ablation was used for the determination of residual stress of a formed plate. Manufacturing processes, like bending, create residual stresses in the product and those can be very disadvantageous for fatigue durability. Residual stresses that are generated during the manu-facturing of products can cause distortions, dimensional errors or can even break the products. The research material was ultra-high-strength steel (UHSS) with a yield strength of 1100 MPa. Speci-mens with a 90 degree bent angle were made by air bending using a press brake. Air bending causes variable residual stress patterns in the cross section of the material. The residual stresses of the formed area were determined by removing material and measuring strains caused by the release of stresses. A slot with the width of 1 mm has been manufactured parallel to the edge, both on the outer and on the inner side of the bend. True residual stress distribution can be calculated from the measured strains. A pumped 1064 nm Nd:YVO4 ablation laser, whose pulse length is 90 ns, was used for the removal of material. This process creates a negligible heat affected zone (HAZ) and laser ablation doesn’t increase stresses in the specimen. The results were compared with those ob-tained when slots were produced by milling and wire-EDM, as well as with the stress values meas-ured by X-ray diffraction.



Main Theme:

Edited by:

J.R. Duflou, R. Clarke, M. Merklein, F. Micari, B. Shirvani and K. Kellens




J. Lämsä et al., "Methods for Determination of Residual Stress of a Formed Plate Using Laser Ablation, Wire EDM and Milling", Key Engineering Materials, Vol. 473, pp. 368-375, 2011

Online since:

March 2011




[1] P.J. Withers, H.K.D.H. Bhadeshia: Residual stress part 1 – Measurement techniques. Material Science and Technology Vol. 17 (2001), p.355–365.

[2] J.E. Wyatt, J.T. Berry: A new technique for the determination of superficial residual stresses associated with machining and other manufacturing processes. Journal of Materials Processing Technology Vol. 171 Issue 1 (2005), p.132–140.


[3] T. Ericsson: The effect of final shaping prior to heat treatment. Handbook of residual stress and deformation of steel. (2008), p.150–158.

[4] W.M. Steen: Laser material processing. Springer (2003), p.408.

[5] M.B. Prime: Residual stress measurement by successice extension of a slot: The crack combliance method. Applied Mechanics Reviews Vol. 52 No. 2 (1999), p.75–96.

[6] M.B. Prime: Plasticity effect in incremental slitting measurement of residual stress. Engineering Fracture Mechanics (2010) p.1–15.

[7] V. Yadav, V.K. Jain, P.M. Dixit: Thermal stresses due to electrical discharge machining. International Journal of Machine Tools and Manufacture Vol. 42 Issue 8 (2002), p.877–888.


[8] J. Siiriäinen: Jäännösjännitysten mittausmenetelmät. Espoo. Tek. korkeakoulu (1999), p.103.

[9] S. Heinilä: Kylmämuovatun putkipalkin väsyminen metsätyökoneen puomirakenteessa – Master's thesis, Lappeenranta University of Technology (2003).

[10] C. Achmus: Messung und Berechnung des Randschichtzustandes komplexer Bauteile nach dem Festwalzen. Clausthal-Zellerfeld: Papierflieger, (1999).

[11] W. Loos: Praktikum Werkstoffkunde/Werkstoffmechanik – Röntgendiffraktometrie, Praktikumsunterlagen, Technische Universität München. München: o.V., o. J.

[12] O. Böllig: Aufbau und Test einer Apparatur zur röntgenographischen Eigenspannungsanalyse, Diplomarbeit, Westfälische Wilhelmsuniversität Münster. Münster: o.V., 1996. 6 Literaturverzeichnis 10.