PSI - Issue 47

Bartłomiej Walczak et al. / Procedia Structural Integrity 47 (2023) 723 – 731 Bart ł omiej Walczak et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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1. Introduction Concern for the natural environment forces manufacturers in the bus industry to look for zero-emission solutions, which is a challenge for engineers. Products such as electric buses are more complex and integrate heavier components. What is more, they must be simple and cheap to manufacture and as light as possible to compensate for the weight of heavy aggregates and to allow the transportation of as many passengers as possible. The bus design process is more complicated and, due to the lack of generally available standards such as for instance UNE EN 12663-1:2011 for the rail industry, requires best practices based on own measurements. The purpose of these activities is to measure the loads acting on the electric bus during normal operation. The results are intended to improve the design process and allow for safe optimization. Fig. 1 shows the proposed workflow to meet this requirement. As a first step, the finite element analysis (FEA) of the prototype structure should be performed to select critical nodes for investigation. The next step is the bus instrumentation and testing of maneuvers and obstacle crossings. This is followed by test drive measurements in urban terrain. The fourth point involves analyzing the data and selecting the sections with the greatest impact on fatigue damage. These sections are to be scanned using kinematic LIDAR in order to obtain a high-quality 3D surfaces. 1.1. Research objectives

Fig. 1.Research workflow.

The data collected will serve to establish parameters for various strength calculations. Static load cases will be determined by the highest registered values obtained from maneuvers and urban driving, while advanced dynamic FEA can be carried out by employing scanned road sections that induced the most significant fatigue damage on the structure. To analyze fatigue life, the processed signal time series from city test drives will be employed. Additionally, data from the reference sensors will be utilized to verify the numerical models. The collected data can also be used to plan accelerated durability tests on special test tracks, as outlined for instance by Kepka and Kepka Jr. (2017). 1.2. Investigated structure As a research model, the Solaris Urbino 15 LE electric bus prototype was chosen, as depicted in, Fig. 2. With a nearly 15-meter length and a maximum gross weight of 26 000 kg, this three-axle electric bus can accommodate more than 100 passengers, 65 of whom can be seated. Its detailed parameters are shown in Table 1.