Nicolas Brötz

Technical University of Darmstadt

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Peter F. Pelz

Technical University of Darmstadt

Manuel Rexer

Technical University of Darmstadt

Philipp Hedrich

Technical University of Darmstadt

Felix Geßner

Technical University of Darmstadt

Christian Bölling

Museum für Naturkunde

Hermann Kloberdanz

Technical University of Darmstadt

Ingo Dietrich

Technical University of Darmstadt

Maximilian Knoll

Krankenhaus der Barmherzigen Brüder Trier

Tristan Gally

Technical University of Darmstadt

Philipp Leise

Technical University of Darmstadt

Cooperative Institutions

Technical University of Darmstadt

Institut für Umformtechnik (Germany)

Materials Science & Engineering

Heidelberg University

Darmstadt University of Applied Sciences

Fraunhofer Institute for Structural Durability and System Reliability

Fraunhofer Society

Technical University of Denmark

TU Wien

University of Stuttgart

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Fluid dynamic vibration absorber for cabin suspension

Nicolas Brötz Manuel Rexer Peter F. Pelz

Truck drivers spend all day moving goods.They are exposed to vibrations every time they drive.Modern cabin suspension and an air-suspended seat already offer a high level of comfort.This, however, is designed for vertical dynamics and you can observe the cab of a truck performs large pitching vibrations during acceleration.These are examined here.A pitch model of the cabin is set up for this purpose.On the basis of this model it is examined which reduction of the vibration can be achieved by the use of a hydraulically translated vibration absorber.The advantage of this absorber is the use of the hydraulic transmission to reduce the heavy mass at high absorber inertia.4 kg of fluid mass act as 131 kg absorber mass reducing vibrations by more than 10%.The conventional vibration absorber is inacceptable due to the additional load.The investigation based on VDI 2057 Part 1 shows that driving comfort can be increased.

Suspension

Dynamic Vibration Absorber

10.25368/2020.103

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Resilience in Mechanical Engineering - A Concept for Controlling Uncertainty during Design, Production and Usage Phase of Load-Carrying Structures

Applied Mechanics and Materials (2018)

Lena C. Altherr Nicolas Brötz Ingo Dietrich Tristan Gally Felix Geßner

Resilience as a concept has found its way into different disciplines to describe the ability of an individual or system to withstand and adapt to changes in its environment. In this paper, we provide an overview of the concept in different communities and extend it to the area of mechanical engineering. Furthermore, we present metrics to measure resilience in technical systems and illustrate them by applying them to load-carrying structures. By giving application examples from the Collaborative Research Centre (CRC) 805, we show how the concept of resilience can be used to control uncertainty during different stages of product life.

Resilience

10.4028/www.scientific.net/amm.885.187

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Citations (25)

Mastering Model Uncertainty by Transfer from Virtual to Real System

Lecture notes in mechanical engineering (2021)

Nicolas Brötz Manuel Rexer Peter F. Pelz

Abstract Two chassis components were developed at the Technische Universität Darmstadt that are used to isolate the body and to reduce wheel load fluctuation. The frequency responses of the components were identified with a stochastic foot point excitation in a hardware-in-the-loop (HiL) simulation environment at the hydropulser. The modelling of the transmission behaviour influence of the testing machine on the frequency response was approximately represented with a time delay of $$10\,\mathrm {ms}$$ 10ms in the frequency range up to $$25\,\mathrm {Hz}$$ 25Hz . This is considered by a Padé approximation. It can be seen that the dynamics of the testing machine have an influence on the wheel load fluctuation and the body acceleration, especially in the natural frequency of the unsprung mass. Therefor, the HiL stability is analysed by mapping the poles of the system in the complex plane, influenced by the time delay and virtual damping. This paper presents the transfer from virtual to real quarter car to quantify the model uncertainty of the component, since the time delay impact does not occur in the real quarter car test rig. The base point excitation directly is provided by the testing machine and not like in the case of the HiL test rig, the compression of the spring damper calculated in the real-time simulation.

Chassis

10.1007/978-3-030-77256-7_4

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Citations (2)

Resilient Product Development - A New Approach for Controlling Uncertainty

Applied Mechanics and Materials (2018)

Philipp Hedrich Nicolas Brötz Peter F. Pelz

By combining the established development method according to VDI guideline 2206 and the new approach of resilience, resilient product development makes it possible to control uncertainty in the early development phases. Based on the uncertainty that can occur in a classical product development process, such as uncertainty due to (i) the transition from function to building structure, (ii) interaction of modules and (iii) planning uncertainty, we first discuss the limits of existing product development guidelines and introduce the concept of resilience. The basic idea is that a resilient process can control uncertainty through the four resilience functions (i) monitoring, (ii) responding, (iii) learning and (iv) anticipating. We apply this new approach to the product development of the actuators of the active airspring of the TU Darmstadt. The active air spring can be used to increase driving comfort in a vehicle or, for example, to minimize kinetosis during autonomous driving.

Resilience

10.4028/www.scientific.net/amm.885.88

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Citations (4)

Integrated Fluid Dynamic Vibration Absorber for Mobile Applications

Nicolas Brötz Philipp Hedrich Peter F. Pelz

Dynamic Vibration Absorber

10.18154/rwth-2018-224361

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Citations (6)

Much does not help much: 3D pareto front of safety, comfort and energy consumption for an active pneumatic suspension strut

Manuel Rexer Nicolas Brötz Peter F. Pelz

With regard to autonomous driving the demands on comfort are increasing.This makes it attractive to use active suspension systems.The system developed at TU Darmstadt is able to increase driving comfort up to 28 % while maintaining driving safety compared to a passive suspension system.This paper investigates the influence of available energy and power of the active system.The investigation is based on a simulation of a quarter car model and an uneven country road.This paper shows that the more energy the active system has at its disposition, the greater is the range between a comfortable and a sporty chassis.Furthermore the driving comfort can be increased by 28 % with constant driving safety.The average power required for this is 15 W and the maximum power is 300 W.

Chassis

Active suspension

Suspension

Active safety

10.25368/2020.91

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Citations (3)

Application of Resilience Metrics to the Fluid Dynamic Vibration Absorber in Drop Tests

Nicolas Brötz Peter F. Pelz

Resilience

Source

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Methods and Technologies for Mastering Uncertainty

Springer tracts in mechanical engineering (2021)

Peter Groche Eberhard Abele Nassr Al-Baradoni Sabine Bartsch Christian Bölling

Abstract Uncertainty affects all phases of the product life cycle of technical systems, from design and production to their usage, even beyond the phase boundaries. Its identification, analysis and representation are discussed in the previous chapter. Based on the gained knowledge, our specific approach on mastering uncertainty can be applied. These approaches follow common strategies that are described in the subsequent chapter, but require individual methods and technologies. In this chapter, first legal and technical aspects for mastering uncertainty are discussed. Then, techniques for product design of technical systems under uncertainty are presented. The propagation of uncertainty is analysed for particular examples of process chains. Finally, semi-active and active technical systems and their relation to uncertainty are discussed.

Identification

Representation

Propagation of uncertainty

10.1007/978-3-030-78354-9_5

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Citations (1)

Strategies for Mastering Uncertainty

Springer tracts in mechanical engineering (2021)

Marc E. Pfetsch Eberhard Abele Lena C. Altherr Christian Bölling Nicolas Brötz

Abstract This chapter describes three general strategies to master uncertainty in technical systems: robustness, flexibility and resilience. It builds on the previous chapters about methods to analyse and identify uncertainty and may rely on the availability of technologies for particular systems, such as active components. Robustness aims for the design of technical systems that are insensitive to anticipated uncertainties. Flexibility increases the ability of a system to work under different situations. Resilience extends this characteristic by requiring a given minimal functional performance, even after disturbances or failure of system components, and it may incorporate recovery. The three strategies are described and discussed in turn. Moreover, they are demonstrated on specific technical systems.

Robustness

Resilience

10.1007/978-3-030-78354-9_6

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Citations (1)

Shock Absorber With Integrated Hydraulic Vibration Absorber to Improve Driving Dynamics

Nicolas Brötz Peter F. Pelz

Shock absorber

Dynamic Vibration Absorber

Dynamics

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