Research into the vibrations of vehicle and mechanical engineering components, as well as into the sound radiation of vibrating structures (generally referred to by the term NVH (Noise, Vibration, Harshness)), has been successfully conducted for many years. For instance, power units installed in a ‘thin-walled’ housing emit a great deal of sound via this housing, which acts as a resonating body. This noise can be significantly reduced through “intelligent” housing design. Extensive parametric studies are used to establish guidelines for the design of acoustically favourable housing configurations and to quantify the “potential noise reduction”. Vibration excitation caused by gear wheels and rolling bearings can be measured directly in the load path on a dedicated gearbox test bench and calculated using multi-body simulation models. This work is underpinned by more than 30 years’ experience in the field of numerical airborne noise calculation and the experimental validation of calculations at every stage, including the auralisation (making audible) of the simulated noises.
In the Laboratory for Structural Mechanics and Acoustics (rooms F028 to F031) there are eight workstations for measurement and simulation tasks, each equipped with appropriate hardware and software.
A separate high-quality anechoic room is available for sound field measurements, as well as a counterpart room with reverberant walls (reverberation room).
Using the reverberation chamber, sound measurements of accuracy class 2 in accordance with DIN EN ISO 3743-1 can be carried out to measure:
The maximum reference cuboid size is 1.2 m³, whereby each dimension must be < 1 m The lower cut-off frequency is 432 Hz.
Full free-field room with a sound absorption coefficient of 99% from 175 Hz. Suitable for:
The internal dimensions of the room are 5.05 x 4.6 x 1.94 m (length x width x height).
StruA-MeaDyn (in-house development), DataPhysics and LMS Test.Lab for:
We have many years of experience with the following software packages for calculating force excitation, e.g. on gears, vibration response and sound radiation:
Project manager: Prof. Dr.-Ing. Jochen Neher
Collaborators: M. Sc. Elias Paul Wilhelm Issel, B. Eng. Samuel Fuchs, Prof. Dr.-Ing. Bernd Graf
Project partners: JASCO Applied Sciences (Europe) GmbH ShipConsult Division, VULKAN Group Service Hackforth Holding GmbH & Co KG, Everllence SE, Hamburgische Schiffbau-Versuchsanstalt GmbH
Project duration: 01.01.2026 - 31.12.2028
Funded by: Federal Government - BMWE
Program name: Maritime Research Program
Project description:
The aim of this project is to reduce low-frequency noise emissions from ships. To this end, innovative bearing element demonstrators made of polyurethane foams (PUR) for large engines are to be developed, which can replace the natural rubber elements commonly used today and contribute to a significant reduction in sound propagation on board ships and under water. Ulm University of Applied Sciences would like to continue its research work in the field of structural mechanics and acoustics and further establish itself as a development partner for the maritime industry through the project. The aim is to create the possibility of developing acoustically highly sophisticated, innovative bearing elements on the basis of simulations and supplemented by the possibilities of test rigs for test specimens and demonstrators of real size. A bearing test rig for determining transfer stiffness is to be developed on an existing basis. Measurements of various demonstrators and batches are to be carried out and virtualized throughout on the basis of simulations. The results obtained are to be used by project partners in the simulations for system design. The development of this expertise at Ulm University of Applied Sciences will strengthen the maritime industry by creating the opportunity to develop sophisticated bearing elements together with partners more quickly and thus also on a project-specific basis.
Project manager THU: Prof. Dr.-Ing. Bernd Graf, Prof. Dr.-Ing. Jochen Neher
Collaborator: M. Eng. Simon Keller
Project partner: Dr. Ing. Ernst Braun GmbH
Project duration: 01.04.2026 - 30.09.2028
Funding provider: Federal Government - BMWE
Program name: ZIM
Project description:
The noise emission of water-cooled electric motors is currently not exactly predictable, resulting in high follow-up costs for subsequent noise reduction measures and avoidable noise pollution overall. Through the targeted development of a test specimen, a new simulation method for noise generation and propagation and experimental investigations, this problem is being fundamentally addressed for the first time in this project.
The aim of the project is to develop a method with which water-cooled electric motors can already be evaluated and optimized in terms of their noise development during the development phase.
Project manager THU: Prof. Dr.-Ing. Bernd Graf, Prof. Dr.-Ing. Jochen Neher
Employees: M. Sc. Elias Paul Wilhelm Issel, M. Eng. Simon Keller, B. Eng. Samuel Fuchs
Project duration: 01.04.2026 - 01.04.2030
Funded by: DFG, MWK, THU
Program name: Large-scale research equipment according to Art. 91b GG
Project description:
The approved renewal of the acoustic test field includes:
Project leader THU: Prof. Dr.-Ing. Bernd Graf
Collaborator: M. Eng. Simon Schneider
Project partner: Faculty of Mathematics at Ulm University
Project duration: from 01.12.2020
Program type: PhD
Project description:
The PhD project is dedicated to the further development of the transient boundary element method in acoustics, with a special focus on practical engineering applications. The main objective of this research project is to improve the efficient calculation of sound radiation caused by structural vibrations of assemblies in mechanical engineering. Since structural vibrations are often the main cause of sound radiation, acoustic calculations are usually based on previous dynamic analysis. In recent years, flexible multi-body simulation (FMBS) has made it possible to capture the dynamic behavior of structures directly in the time domain. However, the calculation of sound radiation in the time domain represents a significant computational burden and can often be prone to instabilities. The project therefore aims to further develop acoustic calculation in the time domain in such a way that it can be carried out in parallel with dynamic simulations, which promises considerable advantages for industrial applications.
Project manager THU: Prof. Dr.-Ing. Jochen Neher
Project partner: DW-Shipconsult GmbH
Project duration: 15.11.2021 - 14.11.2023
Funded by: Federal Government - BMWi
Program name: ZIM
Project description:
In this cooperation project, simulation models for highly stressed bearings of heavy machinery are developed, which enable the valid design of elastic bearing elements with regard to their acoustic effectiveness under different load scenarios. Based on the simulation models, the project aims to develop bearing elements with improved acoustic effectiveness compared to classic natural rubber materials. The acoustic properties of test specimens are to be demonstrated experimentally on a newly developed test rig.
Project manager THU: Prof. Dr.-Ing. Bernd Graf
Project partner: FunctionBay GmbH
Project duration: 01.03.2020 - 28.02.2022
Funded by: Federal Government - BMWi
Program name: ZIM
Project description:
For the efficient development of machine and vehicle components, such as transmissions, the calculation of the expected noise development is essential. Vibrations of non-linear components or transient operating conditions are mainly simulated with multi-body simulation programs (MBS) in the time domain, while the noise calculation is calculated with separate software in the frequency domain. In order to avoid transformation errors, cosimulation software is therefore being developed for the RecurDyn MBS program, for a more resource-efficient sound calculation directly in the time domain. By applying the boundary element method, the number of degrees of freedom to be considered can be extremely reduced, the airborne sound can be calculated in parallel to the structural simulation and analyzed directly after each simulation time step.
In addition to numerical proof of the stability, efficiency and accuracy of the method, an evaluation is carried out with the aid of sound measurements on gearbox housings.
Project manager: Prof. Dr.-Ing. Bernd Wender
Project duration: 10.05.2016 - 09.05.2023
Project type: PhD
Project description:
In the past, the investigation of the acoustic behavior of vehicle transmissions consisted of several consecutive steps. The radiating element, namely the housing, was considered separately from the excitation mechanism of the gear-shaft-bearing system. This is due in particular to the limited computing power. By introducing so-called condensed models for the housing, shafts and gears and meta-models for the rolling bearings, it is now possible to build a multi-body simulation model of the entire gearbox and calculate it in a realistic time. However, the accuracy of this approach has not yet been comprehensively verified by measurement, which requires measurements along the entire sound generation chain. The bearing seats represent a crucial interface, as this is where the vibrations from inside the gearbox are transmitted to the radiating housing. For this reason, a special gearbox was constructed in which the bearing forces are measured directly during operation.
The sensors thus record the interaction between the housing and the gear stages and provide valuable data for validating the calculation. Two types of sensors are used. The sensors record the interaction between the housing and the gear stages and provide valuable data for validating the calculation. Two types of sensors are used. The use of piezoelectric force transducers has already been tested.
In addition, the surface accelerations and the emitted sound power are recorded, which can also be compared directly with the simulation results. This allows the influence of errors in the calculation of the bearing forces on the resulting housing vibration and radiation to be evaluated and statements to be made as to where the calculation approach needs to be made more accurate. Only when it is possible to calculate the sound power accurately enough can the individual gearbox components be subjected to targeted, purely digital optimization. the surface accelerations and the radiated sound power are recorded, which can also be compared directly with the simulation results. This allows the influence of errors in the calculation of the bearing forces on the resulting housing vibration and radiation to be evaluated and statements to be made as to where the calculation approach needs to be more precise. Only when it is possible to calculate the sound power accurately enough can the individual gearbox components be subjected to targeted, purely digital optimization.
Project manager: Prof. Dr.-Ing. Bernd Wender
Project duration: 11/2012 - 06/2016
Project description:
The aim of this research task is to simulate the vibration excitation caused by gear mesh in the transmission. The seat of the bearing outer ring is defined as the interface between the gearbox housing and the gearbox shafts. The multi-body simulation is used to calculate the dynamic forces that are generated by the torque transmission from the driving gear to the driven gear and are introduced into the gearbox housing via the "gear-shaft-bearing" force flow at the seat of the bearing outer ring.
Project manager: Prof. Dr.-Ing. Bernd Wender
Project duration: 10/2012 - 06/2016
Project description:
The aim of this research task is to develop a transmission test bench that can be used to measure the dynamic bearing force in the acoustically relevant frequency range. Measurements are carried out in the speed range from 800 1/min to 3500 1/min and up to a torque of 120 Nm to investigate the vibration excitation of the transmission housing. The concept is based on a standard automotive gearbox and a self-constructed principle gearbox housing with one helical and one spur gear stage. A piezoelectric measuring system has been developed between the bearing outer ring and the bearing seat in the gearbox housing in order to record the dynamic bearing forces in the three axial directions.
Project manager: Prof. Dr.-Ing. Bernd Graf
Project duration: 05/2015 - 04/2016
Project description:
Development and testing of noise reduction measures on a smaller passenger ship on the Danube, the "Ulmer Spatz", which did not comply with the applicable regulation on permissible noise emissions. In order to meet the requirements of the responsible shipping authority, the sound pressure level had to be reduced by approx. 6 dB(A).
The following concept was developed to reduce noise emissions: By recording the actual acoustic boundary conditions, based on a quantitative survey to locate surfaces and components with high sound power/sound radiation, conclusions are to be drawn about relevant sound sources and sound propagation. These findings were used to develop and evaluate possible measures to reduce noise and thus create a detailed plan for implementing the measures.
After the measures were implemented, a comparative measurement was carried out to confirm the effectiveness of the measures, meaning that the shipping authority's acoustic requirements are now being met.
Schneider, Simon; Özdemir, Ceyhun; Gimperlein, Heiko, Urban, Karsten; Graf, Bernd
A stable boundary element method for reliable long-time industrial sound emission
Article in Computational Mechanics, Springer Nature, March 18, 2026
Schneider, Simon; Özdemir, Ceyhun; Gimperlein, Heiko; Urban, Karsten; Graf, Bernd
Stability and Instability of Time-Domain Boundary Element Methods for the Acoustic Neumann Problem
Proceedings in Applied Mathematics and Mechanics, July 30, 2025
Donderer, Matthias
Reducing Engine-Induced Ship Noise at Source
Doctoral Dissertation 2025; Hamburg University of Technology
1st Reviewer: Prof. DSc. (Tech.) Sören Ehlers, Hamburg University of Technology
2nd Reviewer: Prof. Dr.-Ing. Jochen Neher, Ulm University of Technology
Schneider, Simon; Giese, Timo; Marano, Davide:
Gearbox NVH Analysis - An Engineering Approach
Proceedings of the 2024 Fall Technical Meeting (FT), Rosemont IL
Donderer, Matthias; Rieß, Alexander; Waldenmaier, Ulf; Neher, Jochen; Ehlers, Sören:
Participation factor based identification of mode shapes
Proceedings of ISMA 2024, KU Leuven, 2024
Schneider, Simon; Graf, Bernd; Refik, Erin; Giese, Timo:
Advanced practical gearbox NVH analyses: an engineerng guide
Proceedings of ISMA 2024, KU Leuven, Department Werktuigkunde, 2024
Prof. Dr.-Ing. Jochen Neher, Ulm University of Applied Sciences, Dr.-Ing. Dietrich Wittekind, DW-ShipConsult GmbH, Schwentinental
Development of novel spring elements for the elastic mounting of large marine engines
Presentation at the 118th Annual General Meeting of the Schiffbautechnische Gesellschaft e.V.
Dipl.-Ing. Carsten Rickert, Matthias Donderer M. Sc., Dr.-Ing. Ulf Waldenmaier, Prof. Dr.-Ing. Jochen Neher, MAN Energy Solutions SE, Augsburg; Prof. DSc. (Tech.) Sören Ehlers, TUHH
Multibody simulation-based structure-borne noise prognosis for large-bore engines aboard ships
Evaluation of Multibody Simulation-based SBN Prognosis for Large-bore Engines aboard Ships
Presentation at the 118th Annual General Meeting of the Schiffbautechnische Gesellschaft e.V.
Werner, Denis;
Validation of sound power calculation for passenger car transmissions
Dissertation 2023; Ilmenau University of Technology; carried out in the Laboratory for Structural Mechanics and Acoustics at Ulm University of Applied Sciences, supervised and reviewed by Prof. Dr. B. Wender
Schneider, Simon;
Practical Application and Validation of the Time-Domain Boundary Element Method in Acoustics
RecurDyn TechnologyDays, Munich, 03.-04.05.2023
Werner, Denis
Influences on the accuracy of sound power calculations for vehicle transmissions
AVL INTERNATIONAL SIMULATION CONFERENCE 2022; 27-28.09.2022
Werner, Denis; Schneider, Simon; Graf, Bernd; Neher, Jochen; Wender, Bernd:
Sound radiation of gearboxes - Reasons for deviations between calculated and measured sound power levels in NVH analyses,
in: Proceedings of ISMA 2022, KU Leuven, Departement Werktuigkunde, 2022, Pages 15 (No. 138).
ISBN: 9789082893151
Schneider, Simon; Graf, Bernd; Heinrich, Marco; Giese, Timo; Haralampiev, Ivaylo:
Practical application and validation of the time-domain boundary element method in acoustics,
in: Proceedings of ISMA 2022, KU Leuven, Departement Werktuigkunde, 2022, pages 4419-4433 (no. 293).
ISBN: 9789082893151
Donderer, Matthias; Rieß, Alexander; Waldenmaier, Ulf; Neher, Jochen; Ehlers, Sören:
Excitation analysis on resilient mounting eigenmodes of large-bore internal combustion engines,
in: Proceedings of ISMA 2022, 2022, pages 4157 - 4171 (15 pages, no. 221).
Donderer, M.; Rieß, A.; Waldenmaier, U.; Neher, J.; Ehlers, S.:
Efficient Simulation of Damping for Resiliently Mounted Large-Bore Engines.
AVL INTERNATIONAL SIMULATION CONFERENCE 2021; 22.-24.06.2021
Schneider, Simon; Graf, Bernd; Giese, Timo; Haralampiev, Ivaylo:
Validation of the Time Domain Boundary Element Method in Acoustics regarding Flexible Multibody Simulations and Acoustic Measurements,
in: IOP Conf. Series: Materials Science and Engineering World Symposium on Mechanical-Materials Engineering & Science - WMMES 2021, IOP Publishing, IOP Publishing, 2021, pages 10.
DOI: 10.1088/1757-899X/1190/1/012007
ISSN: 1757-8981
Werner, D., Scurria, L., Di Lorenzo, E., Graf, B., Neher, J., Wender, B.; Validation of Multibody NVH Gearbox Calculations with Order Based Modal Analysis and Measurement of Operational Bearing Forces; Proceedings of the International Conference on Noise and Vibration Engineering (ISMA) Leuven, 7. - 9.09.2020
Donderer, M.; Waldenmaier, U.; Neher, J.; Ehlers, S.:
Evaluation of a multibody combustion engine simulation model for underwater noise calculation,
in: ISMA 2020, (ed.), 2020, pages 2001-2012.
ISBN: 978-9-0828-9311-3
Donderer, M.; Waldenmaier, U.; Neher, J.; Ehlers, S.:
Motor vibration simulation for comfort and underwater noise applications
STG Technical Committee Meeting "Vibrations and Noise", Augsburg, 6.2.2020
Donderer, M.; Waldenmaier, U.; Neher, J.; Ehlers, S.:
ACombustion Engine Simulation Model for Underwater Noise Application
DNV GL Nordic Maritime University Workshop 2020, Hamburg, 31.01.2020
Werner,D.; Graf, B.; Falkenberger, S.; Neher, J.; Wender, B.:
Validation of NVH Gearbox Simulations in AVL EXCITE™ with Measurements;
Proceedings of the AVL International Simulation Conference 2019 in Graz (AT), 22. - 24.10.2019
Graf, B., Werner, D.;
On the vibration of gearboxes and generator stator using measured modal parameters only;
Proceedings of the International Conference on Structural Engineering Dynamics (ICEDyn) 2019 Viana do Castelo, 24 - 26.06.2019
Werner, D., Falkenberger, S., Neher, J., Graf, B., Wender, B.; Full model multibody approach for the sound calculation of gearboxes; Proceedings of the International Conference on Noise and Vibration Engineering (ISMA) Leuven, 17 - 19.09.2018
Werner, D., Falkenberger, S., Neher, J., Graf, B., Wender, B.; Calculation Chain for the Sound calculation of Gearboxes with Multibody Models; 13th World Congress on Computational Mechanics (WCCM), New York, 22. - 27.07.2018
Werner, D., Falkenberger, S., Neher, J., Graf, B., Wender, B.; Calculation of the sound radiation of gearboxes; European Altair Technology Conference; Frankenthal, 26.06.2017
Falkenberger, S., Werner, D., Neher, J., Graf, B., Wender, B.;Validation of the measured and calculated dynamic bearing forces in gearboxes concerning the sound radiation of gearboxes;Proceedings of the International CAE-Conference Parma, 17.-18.10. 2016
Falkenberger, S., Werner, D., Neher, J., Graf, B., Wender, B.;Sound radiation of gearboxes - Investigation of the measured and calculated dynamic bearing force in gearboxes;Proceedings of the International Conference on Noise and Vibration Engineering (ISMA) Leuven, 19-21.09.2016
Falkenberger, S., Werner, D., Neher, J., Graf, B., Wender, B.;Validation of the measured and calculated dynamic bearing forces in gearboxes concerning the sound radiation of gearboxes;RecurDyn Technology Days 2016 Munich, 27.04.2016
Werner, D., Falkenberger, S., Neher, J., Graf, B., Wender, B.;Gearbox test bench for determining the accuracy of sound radiation calculations;2016 research report for mechanical engineering in Baden-Württemberg
Falkenberger S., Neher J., Graf B., Wender B.;Experimental and computational studies of the noise generation of gearboxes;ICSV22 Florence (Italy), 12-16.07.2015
Falkenberger S., Neher J., Graf B., Wender B.;Experimental and computational studies of the sound radiation of gearboxes;ICEDyn2015 Lagos (Portugal), 22-24.06.2015
Falkenberger S., Neher J., Graf B., Wender B.;Experimental and computational studies of the sound radiation of gearboxes;ISMA 2014 at the Katholieke Universiteit Leuven (Belgium), 15.-17.09.2014
Falkenberger S., Neher J., Graf B., Wender B.;Computational and experimental studies of the noise development and sound radiation of gearboxes;Research report for mechanical engineering in Baden-Württemberg, WS2013/14.
Neher J., Graf B., Falkenberger S., Wender B.;Sound radiation simulation methods for gearboxes - with a special focus on ribs.;ISMA 2012 at the Katholieke Universiteit Leuven (Belgium), 17.-19.09.2012
Löfflad, J.; Eissner, M.; Graf, B.; Strain gauge Measurements of rotating parts with telemetry;IGHEM 2012 Trondheim (Norway); 27. - 30.06.2012
Neher, J.; Graf, B.; Wender, B.;Simulation methods for the sound radiation of gearboxes;PERMAS User's Conference, Heidelberg, April 26-27, 2012
D'Amico, R.; Neher, J.; Wender, B.; Pierini, M.;On the improvement of the solution accuracy for exterior acoustic problems with BEM and FMBEM;Engineering Analysis with Boundary Elements 36 (2012), pp. 1104-1115
Graf, B.; Chen, L.;Acoustic Fluid-Structural Interaction Method for Modal Analysis with Experimental Results of a Hydraulic Prototype Turbine Runner in Water; 36th MPA-Seminar Stuttgart; 07.10.2010
Graf, B.; Chen, L.;Acoustic Fluid-Structural Interaction Method for Modal Analysis with Experimental Results of a Hydraulic Prototype Turbine Runner in Water;ISMA 2010 at the Katholieke Universiteit Leuven (Belgium), 20.-22.09.2010
Neher, J.; Wender, B.;Validated modeling of joints for the sound radiation simulation of gearboxes;ISMA 2010 at the Katholieke Universiteit Leuven (Belgium), 20.-22.09.2010
Neher, J.; Wender, B.;Simulated Gearbox Noise;NVC 2010, Universiti Kebangsaan Malaysia, Putrajaya, Malaysia, 28.-30.06.2010
Neher, J.; Wender, B.; Modelling of bolted joints for the simulation of the sound radiation; The Sixteenth International Congress on Sound and Vibration (ICSV16), Krakow, 5.-9.7.2009
Husung, S.; Neher, J.; Gramstat, S.; Weber, C.; Wender, B.; Augsburg, K.; Auralization of simulated acoustic properties of a rear axle transmission using VR (Best Paper Award); 8th Paderborn Workshop Augmented & Virtual Reality in Product Development, 29.5.2009
Wender, B.; Simulation of the sound radiation of "thin-walled" housings in machine and vehicle construction; Technical Simulation Economy/ Science, IHK Ulm, 19.3.2009
Graf, B.; Wender, B.; Calculation and reduction of sound radiation from gearbox housings; Forschungswerk 2009, Ulm University of Applied Sciences
B. Eng. Johannes Beckmann
Phone: +49 731 96537-349
Room: F030
Johannes.Beckmann(at)thu.de
M. Eng. Simon Schneider
Phone: +49 731 96537-591
Room: F030
Simon.Schneider(at)thu.de
M. Sc. Elias Paul Wilhelm Issel
Phone: +49 731 96537-594
Room: F030
Elias.Issel(at)thu.de
M. Eng. Simon Keller
Phone: +49 731 96537-723
Room: F030
Simon.Keller(at)thu.de
B. Eng. Samuel Fuchs
Phone: +49 731 96537-669
Room: F030
Samuel.Fuchs(at)thu.de
