PSI - Issue 58

Radovan Minich et al. / Procedia Structural Integrity 58 (2024) 80–86 R. Minich et al./ Structural Integrity Procedia 00 (2019) 000–000

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2. Knowledge base principles There is a need for analyzing hands-on experience from previous development projects and from the operation of existing vehicles and addressing new trends. Current challenges include the rise of electro-mobility and battery powered electric buses, which open new fields of research. Heavy battery packs significantly change the vehicle dynamics and stresses in the chassis and bodywork. Stainless steels and steels of increased strength are widely used in bodywork constructions. In the past, the methodology and specific results were presented several times in professional literature, Kepka and Řehoř (1992), and recently Kepka and Kepka Jr. (2021). Over the years, several milestones have influenced the methodology, Fig. 2, the main ones being: • Participation of the authors in the solution of the European Commission project: Bus-Expert-System for Dynamics Simulation, Design, and Quality Control, Grant agreement ID: CP94-520; • Implementation of design stress spectra according to Heuler and Klätschke (2005); • Introduction of a simplified probabilistic approach to the interpretation of fatigue life according to Kliman et al. (2010). • New R&D projects with bus producers from the Czech Republic and from abroad.

Fig. 2. Publications and key influences to improve the methodology.

The goal of current research and development, carried out as part of doctoral studies, is to create a knowledge base for expert evaluation of the fatigue life of the bodyworks of buses, trolleybuses, and battery electric buses. The knowledge base will be based on a number of already performed laboratory fatigue tests of welded joints of thin-