Collaborative Research Advancing Engineering Solutions for Real-World Challenges 2

In this study a theory of rods is developed and analyzed by taking into account long-range force interactions between cross sections. The balance of momentum and principle of virtual work are formulated. Different variants of the displacement and force boundary conditions are introduced by the specifying force and virtual power fluxes through a cross section of the rod. With a special constitutive assumption for the interaction force a peridynamic type theory is derived. Based on the analytical solutions under both static and dynamic loadings and for several types of boundary conditions including fixed-fixed and fixed-free edges, benchmark problems are formulated. The numerical mesh free type method is applied to solve the governing equations and numerical results are compared with analytical solutions.

The aim of the work is to investigate the behavior of laminated glass plates subjected to ball drop impact. Laminated glasses are known for their safety and impact resistance. One of the important features of laminates is a sufficiently thin polymer interlayer with a pliable structure. This study evaluates the mechanical properties of a laminated glass plate configuration consisting of two glass layers and one layer of polymeric interlayer. The finite element method was used to perform the computational model, that focuses on the dependencies of displacements and first principal stresses on transverse shear strain and the interlayer plate thickness. Results indicate significant insights into the deformation characteristics and stress distribution within the laminated glass structure. The study’s outcomes provide a foundation for further research and development, particularly in optimizing the interlayer properties and thickness for better impact resistance. This work contributes to advancing the knowledge in the field of laminated glass structures, promoting the development of more resilient and safer glass products for various applications.

Hydrogen is a carbon-free alternative to fossil fuels that can be used in internal combustion engines allowing the transfer of know-how gained over the last 100 years of internal combustion engine development. Mass market adoption of these powertrains depend on making them zero-impact vehicles. This means restricting their exhaust emissions even though they are, in most cases, lower than the gasoline counterparts. With this in mind, experiments were carried out in an optically accessible hydrogen-fuelled engine to understand flame propagation through the piston top and ring lands, and to understand oil combustion in these regions. The results were then compared to similar phenomena with gasoline operation in the same engine. A correlation between the observed optical phenomena in the piston lands and the exhaust measurement was also derived which lays the path for improvement of hydrogen internal combustion engines towards zero-impact-emission powertrains. Moreover, indications for the cause of abnormal combustion phenomena could be observed.

The implementation of new methods and tools is essential to achieve the desired shift-left concept of vehicle development. The off-car development method outlines a data-driven approach for the continuous adaptation of vehicle software in accordance with the evolving overall system. With the intention of utilising the exploratory nature of road testing in early development stages, off-car robustness testing and automated off-car calibration are integrated into the product development process. These tools serve to bridge the gap between conceptual design and road testing. It is necessary to provide suitable stimuli for simulations and test benches in order to imitate road testing. To enhance the focus on customer applications, this paper uses test drives to emulate in-service operations. Using a big data infrastructure, an algorithm is presented that enables the efficient determination of probabilistic stimuli.

Electrical steel strips are functional materials employed to enhance the efficiency of motors. The rotor design incorporates small bridges that are critical areas susceptible to failure. For the fatigue assessment of those bridges both statistical size effect and dynamic support effect has to be taken into account. Stress-controlled tests are conducted on NO30-15 using unnotched specimens of varying sizes as well as notched specimens. The material exhibits significant statistical size and support effects. Various methods for determining the Weibull exponent are evaluated based on these test results. By applying concepts of material-mechanical support effects, it is shown that determining the Weibull exponent in the limit lifetime regime results in strong agreement between theoretical predictions and experimental data.

Enhancing the longevity of high-voltage traction inverters is critical for the reliability of future electric vehicles. This paper presents innovative damage mitigation strategies targeting converter components with the highest failure rates. By evaluating two distinct inverter topologies, the research outlines the damage mitigation potential for both semiconductor switches and DC-link capacitors. Advanced control and modulation techniques, such as the selective application of discontinuous pulse-width modulation methods, are used to underscore their efficacy in mitigating damage. Utilizing an extensive dataset from real-world driving conditions, the study comprehensively assesses component degradation and operational longevity. Both explicit and implicit damage avoidance strategies are introduced, with a focus on preemptive and real-time protective measures. An eight-step calculation framework is employed to analyze power losses, thermal behavior, and damage fractions, yielding valuable insights for enhancing the reliability and lifespan of modern power electronic systems.

The improved magnetic force-stroke characteristics of electromagnetic solenoid valves provide benefits for quick-exhaust systems regarding their design, functionality, control strategies and costs. The quick-exhaust membrane, as the key component, is analyzed in terms of design, materials, and performance. A novel control strategy for solenoid valves is introduced, reducing system complexity by replacing an additional valve with a bypass mechanism. System modeling is performed using differential equations for motion and pressure state variables. The simulation model design is verified through the utilization of empirical data, whereby discrepancies are elucidated. This study offers insights into optimizing electro-pneumatic systems and highlights opportunities for more robust, cost-efficient and controllable quick-exhaust concepts.

Industrial networks must meet stringent requirements for security, robustness, and performance to ensure stable and reliable process control in automation environments. These networks achieve the requirements by using isolated and independent special-purpose segments. However, the transformation towards more flexible and modular (SFs) introduces significant challenges. We identify three major transformation factors demanding novel solutions to maintain industrial standards: growing interconnectivity, expanding multi-tenant capability, and increasing application dynamics. This work analyzes the tension between the fundamental requirements and the transformation factors driving the evolution of industrial networks. We also examine existing solutions, highlighting their inadequacies in addressing the comprehensive needs of SFs. The aim is to identify open areas of research necessary for developing equally secure, robust, and high-performing networks in modern industrial settings.

Industry is increasingly using additively manufactured components in the field of laser powderbed fusion (L-PBF). When it is necessary to manufacture complex component geometries in small quantities, common processes like L-PBF come into play. Often, the costs of subtractive, conventional manufacturing processes and the expensive post-processing of the workpiece are higher than when using a generative build-up. However, the use of these conventional manufacturing processes remains common. This is due to the extensive knowledge and research on the mechanical properties and material behavior during processing. In contrast, the material behavior of the metal powder is significantly and seemingly uncontrollably influenced by high heating and cooling rates, dynamic melt pool behavior and spatter formation. The standard Gaussian energy density distribution of a laser beam has certain physical limits when processing powder material. This is where beam shaping comes into play. Specially manipulated laser beam intensity distributions have a direct influence on the behavior of the molten pool, making the mechanical properties of the material more controllable. This paper, therefore, deals with various methods of beam shaping. This paper summarizes potential defects in an additively manufactured component and demonstrates how shaped laser beams can minimize these defects. The last chapter shows a schematic test setup that should lay the foundation for future research on this topic.

This study investigates the fluid mechanical behaviour of outgoing free jets from circular nozzles, focusing on jet angle and velocity profile analysis. Two nozzles with outlet diameters of 8 and 12 mm were examined using schlieren photography and Pitot tube measurements. Schlieren imaging revealed a consistent jet angle of approximately 22\(^{\circ }\) unaffected by variations in pressure or nozzle diameter. Additionally, the schlieren method revealed that turbulence within the jet boundary increased at lower pressures due to greater mixing with the ambient air. The velocity profiles, obtained through dynamic pressure measurements, followed a Gaussian distribution within the core and transition regions, with the larger 12 mm nozzle producing a more stable and extended core region compared to the 8 mm nozzle. Deviations were observed near the jet boundaries, particularly at lower velocities, highlighting the challenges in measuring low dynamic pressures. The study’s findings contribute to the understanding of free jet dynamics, offering insights for optimising industrial cooling and drying systems.

This chapter provides an introduction to the topic of judging the lightweight potential of structures. Two different concepts, i.e. the so-called lightweight index and the specific energy absorption, are discussed. The basic idea of shape optimization is discussed in the context of one-dimensional structural members, i.e., bars and beams, and one- and two design variables are considered.