The European Group of Research in Tolerance (E-GRT) consists of the French Group of Research in Tolerance (GRT), Wingquist Laboratory at Chalmers University, the Mechanical Engineering Department of the Polytechnico of Milan and the Chair of Engineering Design of the Friedrich-Alexander University Erlangen-Nuremberg.
The first E-GRT seminar was held in Erlangen 2015, followed by a second seminar in Metz 2017.
During the seminar, young PhD students and researchers in the field of tolerance and geometric variation management, get the opportunity to present and discuss new ideas and approaches. Senior researcher will contribute to intensive discussions at their specific experience.
From Additive Manufacturing to Perceived Quality
This year's program was divided into five sessions: Additive Manufacturing, Digital Twins, Robust Design, Tolerance Analysis and Perceived Quality.
Some examples among the presentations: Hallman, Schleich and Wartzack proposed a novel approach for the process-oriented "Statistical Tolerance Analysis of Additively Manufactured Non-Assembly Mechanisms" and the use of appropriate meta-models.
Zhu, Ferreira, Anwer and Mathieu, ENS Paris-Saclay talked about "Data-driven Skin Model Shapes for Additive Manufacturing" which strives to streamline modeling to avoid geometric deviations.
Other AM-related tolerance issues were highlighted when researchers from Bordeaux and Grenoble talked about geometrical defects occurring in EBM (Electron Beam Melting) and SLM (Selektive Laser Melting) overhang parts.
Chalmers University of Technology and Wingquist Laboratory presented papers within geometrical assurance. One example was Aderiani, Wärmefjord and Söderberg on “Selective Assembly and Individualized Locator Adjustments in Improving Geometrical Quality of Assemblies” which presents new methods and tools to develop the application and study of two techniques in compliant assemblies, particularly sheet metals.
(Scroll down for full list of presentations)
Simulation and Digital twins - hot future topics
The day ended with a summary of the director Rikard Söderberg, and co-director Kristina Wärmefjord, where the results of a survey was presented. It concluded that Simulation and Digital twins are the two most important areas in future development for both industrial and academic societies, regarding tolerancing. The survey also found that group together held almost 300 years of competence within tolerancing!
Upcoming events
Nabil Anwer, ENS Paris-Sanclay, reminded the audience of some upcoming conferences:
6-8 May, 2020
CIRP Design 2020 with conference theme “Enhancing design through the 4th revolution thinking”, Kruger national Park, South Africa
15-17 June, 2020
The 16th CIRP CAT Conference, with conference theme “Opportunities and constraints in the standardization of geometrical product specifications”, Charlotte NC, USA
Nabil Anwer ended with an early save-the-date for CIRP CAT 2022, that will be held in Metz, France.
Text: Carina Schultz
Photos: Carina Schultz, Abolfazl Rezaei Aderiani and Marcus Folino

Professor Rikard Söderberg, director for Wingquist Laboratory, held the closing session.
Kostas Stylidis presented "Perceived Quality in the Age of Industry 4.0"
"Selective Assembly and Individualized Locator Adjustments in Improving Geometrical Quality of Assemblies" was the title of Abolfazl Rezaei Aderianis presentation.
Kristina Wärmefjord presented the results from the survey among the researchers at the conference.
Nabil Anwer, Professor at ENS Paris-Sanclay, reminded the audience about upcoming conferences.
Presentations at the 3rd Seminar of the European Group of Research in Tolerancing (E-GRT)
Chalmers University of Technology, 18-19th June, 2019
SESSION 1 – Additive Manufacturing
Statistical Tolerance Analysis of Additively Manufactured Non-Assembly Mechanisms
Martin Hallmann, Benjamin Schleich, and Sandro Wartzack
Friedrich-Alexander-University Erlangen
Data-Driven Skin Model Shapes for Additive Manufacturing
Zuowei Zhu, Kevin Ferreira, Nabil Anwer, and Luc Mathieu
LURPA, ENS Paris-Saclay, Université Paris-Sud, Université Paris-Saclay
A volumetric lifecycle management for additive manufacturing
Stefano Petrò and Giovanni Moroni
Politecnico di Milano
Investigation on geometrical defects occurred in EBM and SLM overhang parts
Soukaina Ghaoui, Yann Ledoux and Alex Ballu from University of Bordeaux, Talence, together with
Thanh Hoang VO, Matthieu Museau, Frédéric Vignat and François Villeneuve from University of Grenoble Alpes, Grenoble
SESSION 2 – Digital Twins
Selective Assembly and Individualized Locator Adjustments in Improving Geometrical Quality of Assemblies
Abolfazl Rezaei Aderiani, Kristina Wärmefjord, and Rikard Söderberg
Chalmers University of Technology, Gothenburg
Spot Welding Sequence Optimization in a Geometry Assurance Digital Twin
Roham Sadeghi Tabar, Kristina Wärmefjord, and Rikard Söderberg
Chalmers University of Technology, Gothenburg
SESSION 3 – Robust Design
Robust and tolerance design in early product development stages
Stefan Goetz, Benjamin Schleich, and Sandro Wartzack
Friedrich-Alexander-University, Erlangen
Barriers for efficient virtual assessment of structural robustness
Tim Brix Nerenst, and Tobias Eifler
Technical University of Denmark
SESSION 4 - Tolerance Analysis
Tolerance analysis; Overview of intermediate results of AHTOLAnD (French research project): Statistical tolerance analysis of over-constrained mechanisms with form defects & Tolerance sensitivity assessment
Lazhar Homri (1), Pierre Beaurepaire (2), Edoh Goka (1), Dana Idriss (2), Nicolas Gayton (2), Jean-Yves Dantan (1), Antoine Dumas (3), and Paul Clozel (4)
(1) LCFC, Arts et Métiers ParisTech, ENSAM, METZ
(2) Université Clermont Auvergne, CNRS, SIGMA Clermont
(3) Phimeca SA, Paris
(4) Mecamaster, Ecully
Demo RD&T software for variation simulation
Rikard Söderberg, Lars Lindkvist, Kristina Wärmefjord
SESSION 5 – Perceived Quality
Perceived Quality in the Age of Industry 4.0
Kostas Stylidis and Rikard Söderberg
Chalmers University of Technology, Gothenburg