PSI - Issue 77

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ScienceDirect

Procedia Structural Integrity 77 (2026) 272–278

© 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSI organizers Keywords: Type your keywords here, separated by semicolons ; Abstract The operation of city buses, trolleybuses and battery buses on uneven roads causes dynamic and variable amplitude loading of these road vehicles. Such loading can lead to fatigue damage to critical nodes of the bodywork or other vehicle components. Stress time histories are most often random processes. Such loading processes can be determined by measurement. Fatigue analysis of these processes is fundamentally different from dynamic analysis. Dynamic analyses are performed in the frequency domain. Fatigue analyses must be performed in the time domain to determine the so-called load spectra (histograms of load cycles). Fatigue damage can then be estimated using an appropriate fatigue damage accumulation hypothesis. The contribution presents the results of extensive measurements on several vehicles and in various operating conditions. The so-called design stress spectra for bodywork dimensioning and load spectra for laboratory tests of their critical structural nodes are derived. 1. Introduction In real-world operation, structures encounter much more complex conditions than static or simple harmonic oscillating loading. They are often exposed to dynamic effects that are characterised by randomness, sometimes even International Conference on Structural Integrity Service load analyses for fatigue life calculations and laboratory tests of welded joints of trolleybus bodyworks Miloslav Kepka a, *, Miloslav Kepka jr. a , Radovan Minich a , Jaroslav Vaclavik b a University of West Bohemia, Faculty of Mechanical Engineering, Regional Technological Institute, Univerzitni 2732/8, 301 00 Pilsen, Czech Republic b Research and Testing Institute Pilsen Ltd., Tylova 1581/46, 301 00 Pilsen, Czech Republic

* Corresponding author. Tel.: +420 604 831 035; fax: +420 377 631 112 E-mail address: kepkam@fst.zcu.cz

2452-3216 © 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSI organizers 10.1016/j.prostr.2026.01.036