Research seminar "FE ohne Schnee" 2025 in Kleinwalsertal

From July 20-23, 2025, three members of our institute participated in the seminar "FE ohne Schnee" in Hirschegg, Austria. The event serves as a special platform for informal scientific exchange between various statics and mechanics institutes at German universities. This year, participants included representatives from the Technical University of Munich, the Technical University of Dortmund, the Leibniz University of Hannover, RWTH Aachen University, the Karlsruhe Institute of Technology, and the University of Stuttgart. Representing our institute this year were Prof. Dr.-Ing. Josef Kiendl, Dr.-Ing. Georgios Michaloudis, and Dr.-Ing.  Mehul Lukhi.

At the 20th FE ohne Schnee Conference in Hirschegg, Dr.-Ing. Mehul Lukhi presented his latest research on "Comprehensive Analysis of Fracture Behavior in Single-Walled FFF PLA Specimens Using DIC, SEM, and Photographic Imaging".

This study investigates how grid orientation affects fracture mechanisms in FDM-printed single-walled PLA specimens. It combines mechanical testing with digital image correlation (DIC), high-resolution photography, and scanning electron microscopy (SEM). Grid angles from 0° to 90° were systematically analyzed under uniaxial tensile loading.

The results showed a transition from strong, brittle transfilament failure at 0° (where the filaments align in the loading direction) to weak, interfacially adhesive failure at 90°, where the crack paths followed the filament boundaries. In particular, in the angular range from 45° to 60°, mixed behavior was observed, with fracture influenced by both shear and the quality of the interfacial bond. Full-area DIC strain maps captured crack initiation and propagation, while SEM imaging provided microscopic insights into the fracture surface morphology across different orientations.

Dr. Lukhi's contribution highlights the importance of understanding anisotropic fracture behavior in FDM structures and provides valuable data for future material model calibration and simulation of 3D printed components.

A varied supporting program, including hikes through the Breitachklamm and up the Hohen Ifen, also offered the opportunity for joint activities and in-depth professional discussions.

Our sincere thanks go to the Institute of Structural Analysis at the University of Stuttgart, especially Dr.-Ing. Malte von Scheven, for the excellent organization.

^{Images: Copyright © 2025, Josef Kiendl}