Quiroga Mellado, Juan AntonioGonzález Cano, Agustín2023-06-202023-06-201998-080957-023310.1088/0957-0233/9/8/010https://hdl.handle.net/20.500.14352/58797© 1998 IOP Publishing Ltd. We thank Professor Eusebio Bernabeu, director of the Optics Department of the Universidad Complutense for his help and continuous support. Also, we thank Hans Steinbichler, of Steinbichler Optotechnik GmbH, for his technical assistance. This work has been partially supported by project MAT 95-0767 of the CICYT (Comisión Interministerial de Ciencia y Tecnología).An application of multigrid techniques for the separation of principal stresses in plane stress systems is presented. By establishing the equilibrium equations and determining the value of shear from photoelastic data a system of partial differential equations is obtained, which can be solved by applying a multigrid method. Multigrid methods are comparable to Fourier methods in efficiency and robustness and can be applied to processing areas of arbitrary shape.engjournal articlehttp://dx.doi.org/10.1088/0957-0233/9/8/010http://iopscience.iop.org/open access535PhaseÓptica (Física)2209.19 Óptica Física