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Hire Clemens D.
Germany
USD 40 /hr

Automotive Engineering Research Consultant | Technical Manuscript Review | Publication Strategy

Profile Summary
Subject Matter Expertise
Services
Research Scientific and Technical Research
Consulting Scientific and Technical Consulting
Work Experience

Resarcher

Chair of Automobile Engineering | TU Dresden

September 2023 - Present

Researcher

Automobilforschung Dresden

July 2017 - September 2023

Education

Dipl-Ing.

Technische Universität Dresden - Germany

October 2014 - June 2017

BEng in Mechanical Engineering

Hochschule für Technik, Wirtschaft und Kultur Leipzig (FH) - Germany

October 2011 - September 2014

Certifications
  • Certification details not provided.
Publications
JOURNAL ARTICLE
Clemens Deubel, Benjamin Dittrich, Johannes Meinck, Günther Prokop (2026). Experimental analysis and modelling of friction in automotive shock absorbers operating under side forces . Tribology International.
Experimental analysis and modelling of friction in automotive shock absorbers operating under side forces @article{ea96b648401740cb859617d84a2865d1, title = "Experimental analysis and modelling of friction in automotive shock absorbers operating under side forces", abstract = "In automotive suspension systems, the shock absorber plays a crucial role in decoupling the chassis from the wheel, making its design essential for achieving a good ride comfort. In addition to the damping force generated by hydraulic shock absorbers, the friction significantly contributes to the total force particularly at low relative velocities. For strut-type suspensions, fluctuating side forces considerably impact the normal loads of the friction contacts and thus the friction state. However, its dynamics under varying normal loads have not yet been thoroughly investigated and modelled, which is necessary to accurately analyse the effect of shock absorber friction in vehicle dynamics simulations. In this study, both stationary and non-stationary friction phenomena occurring in an automotive shock absorber are presented. The observances highlight the interdependent effect of relative velocity and normal force on the friction force. This requires new modelling approaches and is addressed by extending the LuGre formulation. The proposed formulation more accurately replicates the experimentally observed non-stationary behaviour over a wide variation of velocities and side forces during sine excitation. An iterative parameterisation process enables the incorporation of varying normal force effects on the Stribeck curve by expressing parameters as side-force dependent, which is new to the field. The enhanced friction model is validated using stochastic, real-driving shock absorber motion sequences, confirming a good agreement with the experimentally observed friction force. Based on this, a simplified heuristic approach is developed that further increases accuracy and is suitable for future suspension simulation. Eventually, a much higher accuracy can be achieved compared to state-of-the-art models.", keywords = "Friction lag, Stribeck curve, Shock absorber, Friction modelling, Parameter identification", author = "Clemens Deubel and Johannes Meinck and G{\"u}nther Prokop", note = "Publisher Copyright: {\textcopyright} 2025 The Authors.", year = "2026", month = mar, doi = "10.1016/j.triboint.2025.111328", language = "English", volume = "215", journal = "Tribology International", issn = "0301-679X", publisher = "Elsevier, New York [u. a.]", number = "Part A", } . Tribology International.
Clemens Deubel, Tobias Schramm, Günther Prokop (2026). A suspension friction model to investigate the influence of degraded shock absorbers on vehicle dynamics . Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering.
A suspension friction model to investigate the influence of degraded shock absorbers on vehicle dynamics @article{92ef7f70e8fb49338a9c4875d0c4bf97, title = "A suspension friction model to investigate the influence of degraded shock absorbers on vehicle dynamics", abstract = "Friction in vehicle suspensions is an important property for modeling vertical dynamics. Conventionally, suspension friction is modeled with a simple Dahl friction model in full vehicle simulation models. However, this approach appears to be insufficient for investigations involving degraded shock absorbers or semi-active damping systems. At high shock absorber excitation velocities, the suspension friction is overshadowed by the fluid force of the shock absorbers. When investigating the effect of degraded shock absorbers due to oil and gas loss on the driving dynamics of passenger cars, the correct representation of suspension friction is particularly important, since the masking effect of the hydraulic force is absent for these conditions. This work therefore presents a phenomenological mathematical model of suspension friction, which takes into account the dependencies of suspension friction on the deflection velocity of the vehicle shock absorbers, the oil level of the vehicle shock absorbers and the horizontal forces on the wheel carriers. To parameterize the model, measurements of a MacPherson axle and a fixed beam axle as well as of various vehicle shock absorbers are analyzed. To validate the model approach, a test vehicle with identical axles is used to perform single obstacle crossings at 8 km/h and sinusoidal steering at 50 km/h for the intact vehicle and for oil-empty front axle shock absorbers and oil-empty rear axle shock absorbers. The driving tests are simulated using a mathematical, characteristic curve-based five-mass full vehicle model. The simulation results show that the presented friction model is necessary to obtain a high level of accordance between the simulation and experimental investigation of driving maneuvers with degraded shock absorbers. If the suspension friction for the vehicle with oil-empty rear axle shock absorbers is modeled using a Dahl friction model considering only nominal conditions, that is neglecting the aforementioned impacts on the amount of friction, a root-mean-square error that is 65 times higher is calculated.", keywords = "vehicle dynamics, degradation, numerical simulation, friction model, shock absorber", author = "Tobias Schramm and Clemens Deubel and G{\"u}nther Prokop", note = "Publisher Copyright: {\textcopyright} IMechE 2026. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).", year = "2026", month = jan, day = "2", doi = "10.1177/09544070251381918", language = "English", journal = "Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering", issn = "0954-4070", publisher = "SAGE Publications", } . Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering.
Clemens Deubel, Günther Prokop (2025). The relevance of shock absorber friction on the total friction of a MacPherson suspension system during lateral manoeuvres . Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering.
Clemens Deubel, Bastian Schubert, Günther Prokop (2025). Quasi-static shock absorber friction at low velocity reciprocating sliding conditions . Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering.
Quasi-static shock absorber friction at low velocity reciprocating sliding conditions @article{be9ec97a1a6c439882280102a9feac90, title = "Quasi-static shock absorber friction at low velocity reciprocating sliding conditions", abstract = "The characteristics of vehicle shock absorbers have a major significance regarding vehicle dynamics, thus affecting vehicle ride comfort, handling and safety. Although much research focuses particularly on the hydraulic damping properties of this vital suspension component, friction properties are not considered in great detail. However, for driving scenarios of low excitation and velocity of the shock absorber due to moderate roughness of the road, the friction force generated by the shock absorbers and the remaining components is particularly important regarding the transfer of vibration from the road to the passenger. Hence, this study investigates the sensitivity of shock absorber friction to various parameters in the quasi-static domain. The effects of side force, temperature, excitation amplitude and waveform are determined for multiple shock absorbers. The results show no significant influence of the amplitude and waveform used in the conducted tests. Contrarily, the friction force strongly depends on the side force, which represents the variable load perpendicular to the shock absorber{\textquoteright}s main axis arising during various driving events for MacPherson suspensions. An increased temperature reduces the side force effect.", keywords = "Damper friction, friction, MacPherson, shock absorber friction, side force, side load", author = "Clemens Deubel and Bastian Schubert and G{\"u}nther Prokop", note = "Publisher Copyright: {\textcopyright} IMechE 2023.", year = "2025", month = jan, doi = "10.1177/09544070231201688", language = "English", volume = "239", pages = "391--402", journal = "Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering", issn = "0954-4070", publisher = "SAGE Publications", number = "1", } . Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering.
Effect of Shock Absorber Friction on Vehicle Vertical Dynamics @article{bf29e11e29764d41ba428c4219d0e966, title = "Effect of Shock Absorber Friction on Vehicle Vertical Dynamics", abstract = "In order to efficiently predict and investigate a vehicle's vertical dynamics, it is necessary to consider the suspension component properties holistically. Although the effects of suspension stiffness and damping characteristics on vertical dynamics are widely understood, the impact of suspension friction in various driving scenarios has rarely been studied in both simulation and road tests for several decades. The present study addresses this issue by performing driving tests using a special device that allows a modification of the shock absorber or damper friction, and thus the suspension friction to be modified independently of other suspension parameters. Initially, its correct functioning is verified on a shock absorber test rig. A calibration and application routine is established in order to assign definite additional friction forces at high reproducibility levels. The device is equipped in a medium-class passenger vehicle, which is driven on various irregular road sections as well as over single obstacles. For all tested road sections, a linear decrease of ride comfort in terms of specific relevant vertical objective values is found by increasing the friction force. This emphasizes a definite link between suspension friction and vertical vehicle body vibration, resulting in a negative impact on vertical ride comfort. However, the longitudinal vehicle body vibration is not significantly affected. The relevance of friction in terms of transmitting the energy associated with road unevenness to the chassis in the frequency range of the chassis' natural frequency is found to be remarkably high on smooth roads, and still considerably high on bumpy roads. The chassis and wheel resonance frequencies are significantly friction-dependent due to the damper's slip or stick states. The results obtained from smooth road tests demonstrate the practical relevance of accurately considering friction for the given suspension type in terms of vertical ride comfort prediction.", keywords = "Correlation, Damper Friction, Field Test, Friction, MacPherson, Ride Comfort, Shock Absorber Friction, Vertical Dynamics", author = "Clemens Deubel and Schneider, \{Scott Jarod\} and G{\"u}nther Prokop", note = "Publisher Copyright: {\textcopyright} 2023 SAE International. All Rights Reserved. ", year = "2024", month = apr, day = "10", doi = "10.4271/10-08-02-0010", language = "English", volume = "8", journal = "SAE International Journal of Vehicle Dynamics, Stability, and NVH", issn = "2380-2162", publisher = "SAE INT", number = "2", } . SAE International Journal of Vehicle Dynamics, Stability, and NVH.
Velocity and load dependent dynamic shock absorber friction at stationary conditions @article{1ea8e4965c4c4b348bf456a984634769, title = "Velocity and load dependent dynamic shock absorber friction at stationary conditions", abstract = "When it comes to vehicle vertical dynamics, the characteristics of shock absorbers are of high importance. With the increasing use of active suspension systems, it becomes possible to adapt the hydraulic damping force to the road event, while the friction force is not controllable. As a result, friction becomes more relevant and can negatively affect passenger ride comfort. In many mechanical applications, it is observed that friction in lubricated sliding conditions is velocity and load dependent. In contrast, shock absorber friction, and therefore suspension friction, is commonly considered as quasi-static, i.e. characterised by a constant potential. Since the shock absorber is predominantly in motion over a wide velocity range, it is necessary to improve the understanding of friction characteristics especially in the dynamic domain. In this study, modified valve-free shock absorbers are presented that allow the observation of dynamic friction properties experimentally. As not covered by previous studies, the effect of side force (load) as a main parameter to increase friction is investigated. It is observed that its effect varies significantly with velocity and alters the stationary friction-velocity curve, also known as the Stribeck curve. In addition, the shape of the Stribeck curve depends strongly on the shock absorber's oil volume. These novel results emphasise a substantial, interdependent influence of load and velocity on the (elasto-)hydrodynamic properties of the dynamic shock absorber friction force, which was not identified in the literature. The dynamic friction force exceeds the quasi-static friction force multiple times, and also exceeds the hydraulic damping force for considerable side forces in the lower velocity range up to 60 mm/s. Consequently, the total shock absorber force under presence of side force is determined. The findings can be used to improve active suspension control or to improve vehicle simulation by enabling the parametrisation of dynamic shock absorber friction models.", keywords = "Friction, MacPherson, Shock absorber, Stribeck curve", author = "Clemens Deubel and Bastian Schubert and G{\"u}nther Prokop", note = "Publisher Copyright: {\textcopyright} 2024 The Authors", year = "2024", month = feb, day = "15", doi = "10.1016/j.triboint.2024.109424", language = "English", volume = "193 (2024)", journal = "Tribology international", issn = "0301-679X", publisher = "Elsevier, New York [u. a.]", } . Tribology international.
Clemens Deubel, Günther Prokop (2024). Friction of a MacPherson suspension system at various load cases . Journal of Vibration and Control.
Deubel, Clemens, Prokop, Guenther (2024). Friction of a MacPherson suspension system at various load cases . Journal of Vibration and Control.
Clemens Deubel, Hannes Jochen Vincenz, Günther Prokop (2023). Shock absorber friction testing on a MacPherson suspension considering realistic mounting situation . Journal of Vibration and Control.
C. Deubel, S. Ernst, G. Prokop (2023). Objective evaluation methods of vehicle ride comfort—A literature review . Journal of Sound and Vibration.
Deubel, C., Ernst, S., Prokop, G. (2023). Objective evaluation methods of vehicle ride comfort-A literature review . Journal of Sound and Vibration.
Deubel, Clemens, Vincenz, Hannes Jochen, Prokop, Gunther (2023). Shock absorber friction testing on a MacPherson suspension considering realistic mounting situation . Journal of Vibration and Control.
Daniel Derrix and Clemens Deubel and Jan Kubenz and Günther Prokop(2021). Experimental Analysis of the Influence of Body Stiffness on Dynamic Suspension Kinematics and Compliance Characteristics and Dynamic Body Behavior . SAE International Journal of Vehicle Dynamics, Stability, and NVH. 5. (4). {SAE} International
Experimental Analysis of the Influence of Body Stiffness on Dynamic Suspension Kinematics and Compliance Characteristics and Dynamic Body Behavior @article{e98570d6347c4c7a92aab7685a00f097, title = "Experimental Analysis of the Influence of Body Stiffness on Dynamic Suspension Kinematics and Compliance Characteristics and Dynamic Body Behavior", abstract = "Many disciplines of the current vehicle development process are still based on subjective scoring of prototypes, especially in the field of vehicle dynamics. To further reduce the need for hardware and to discover possible weaknesses early in the development process and therefore reduce costs, suitable simulative methods are required. The influence of body and chassis stiffness on vehicle dynamics is not fully understood and requires further research to implement reliable simulative methods. The development of methods requires an understanding and objective depiction of the physical chain. The influences of stiffening beams at the front of a vehicle on the static and dynamic response of wheels and body are observed by using static and dynamic suspension kinematics and a compliance test rig setup. This response is assessed by acceleration sensors, strain gauges, and optical measurement of wheel positions. Static load cases show that minor differences are caused by varying the vehicle's stiffness. I n the dynamic case, greater differences can be observed, especially by the acceleration sensors applied to the body. Dynamic assessment of the body and chassis stiffness can support future development of light and robust bodies and chassis while allowing for cost reduction by decreasing the need for hardware. Further research and objectification will lead to simulative models that can replace prototypes.", keywords = "Body stiffness, Dynamic test rig, K\&C, Kinematics and compliance, Sensitivity analysis, Suspension, Vehicle dynamics", author = "Daniel Derrix and Clemens Deubel and Jan Kubenz and Guenther Prokop", note = "Publisher Copyright: {\textcopyright}", year = "2021", month = jul, day = "14", doi = "10.4271/10-05-04-0032", language = "English", volume = "5", pages = "475--487", journal = "Sae international journal of vehicle dynamics stability and nvh", issn = "2380-2170", publisher = "SAE INT", number = "4", } . Sae international journal of vehicle dynamics stability and nvh.
Deubel, Clemens, Derrix, Daniel, Kubenz, Jan, Prokop, Guenther (2021). Experimental Analysis of the Influence of Body Stiffness on Dynamic Suspension Kinematics and Compliance Characteristics and Dynamic Body Behavior . SAE International Journal of Vehicle Dynamics, Stability, and NVH.
Deubel, Clemens, Liu, Chao, Zhang, Yi, Kocksch, Felix, Kubenz, Jan, Prokop, Guenther (2020). Identification of Kinematic Points Based on KnC Measurements from the Suspension Motion Simulator . Lecture Notes in Mechanical Engineering.
Experimental analysis of suspension kinematics and compliance characteristics of sensitivities and combined load cases with the suspension motion simulator @article{e7f55bfc2d81448a828545885ea628d0, title = "Experimental analysis of suspension kinematics and compliance characteristics of sensitivities and combined load cases with the suspension motion simulator", abstract = "The vehicle handling dynamics stands in the central place of the automotive developing processes. The accurately parameterized vehicle handling models play an important and useful role at different vehicle developing phases. At the early phase of vehicle development, they can be used to set the desired target by comparing the handling characteristics of competitors' vehicles. For the further developments of active systems, the right parameterized models are the basis to design the control systems in a virtual simulative environment. Therefore, there are the strong needs to develop a systematic methodology to parametrize the vehicle handling models, whose qualities should also be assured by the validation of field tests. The kinematics and compliance (KnC) behavior of the suspension is in the focus of this study. Compared with parameterization methods of other chassis subsystems, sensitivity analyses of suspension KnC testing conditions were very few in literatures published. With the help of the Suspension Motion Simulator (SMS) from MTS Systems Corporation, different factors of testing conditions (such as testing speeds, tire pressures, damper temperatures etc.) have been researched as to find appropriate testing conditions for a reliable and accurate data set of vehicle handling models. Generally for standard KnC testing maneuvers, movement or force \& moment is only in one degree of freedom applied, which is not exactly the same as in the real vehicle driving conditions. New testing maneuvers considering various combined load cases were developed and conducted. A new testing maneuver including the roll movement and lateral compliant inputs is suggested for parameterization of vehicle handling models, as it reproduces more realistic vehicle driving conditions during cornering.", author = "Chao Liu and Clemens Deubel and Junyu Zhou and Axel Gerhard and Jan Kubenz and G{\"u}nther Prokop", note = "Publisher Copyright: {\textcopyright} 2019 SAE International. All Rights Reserved.; SAE World Congress Experience 2019, WCX 2019 ; Conference date: 09-04-2019 Through 11-04-2019", year = "2019", month = apr, day = "2", doi = "10.4271/2019-01-0852", language = "English", volume = "2019-April", journal = "SAE Technical Papers", publisher = "SAE International, Warrendale", number = "April", } . SAE Technical Papers.
BOOK CHAPTER
Clemens Deubel, Günther Prokop, Rico Zimmermann (2024). Cyberphysical Attribute Testing in Vehicle Dynamics, ADAS, and Automated Driving .
Clemens Deubel, Chao Liu, Yi Zhang, Felix Kocksch, Jan Kubenz, Günther Prokop(2020). Identification of Kinematic Points Based on KnC Measurements from the Suspension Motion Simulator . 1786--1793Springer International Publishing
CONFERENCE PAPER
(2020). Hybrid Approach to Identify Kinematic Points of a Suspension System. FISITA Web Congress 2020.
Clemens Deubel, Chao Liu, Yi Zhang, Felix Kocksch, Jan Kubenz, Guenther Prokop(2020). Identification of Kinematic Points Based on KnC Measurements from the Suspension Motion Simulator . ADVANCES IN DYNAMICS OF VEHICLES ON ROADS AND TRACKS, IAVSD 2019. Microsoft.AspNetCore.Mvc.Localization.LocalizedHtmlString 1786--1793. Springer International Publishing AG
OTHER
Clemens Deubel, Chao Liu, Junyu Zhou, Axel Gerhard, Jan Kubenz, Günther Prokop(2019). Experimental Analysis of Suspension Kinematics and Compliance Characteristics of Sensitivities and Combined Load Cases with the Suspension Motion Simulator . SAE Technical Paper Series. {SAE} International