RG Off-Road Machines About Us The Research Group for Off-Road Machines was established in December 2002 at Ruhr-Universität Bochum. It has since then been under the supervision of Prof. Dr.-Ing. Jan Scholten (junior professor). Our main goal is the focusing and increase of teaching and research activities in the field of OffRoad Machines in Bochum. Through our practice-oriented approach in research and teaching, we are a scientific partner for the industry and the bridge between our students and their future field of work. Our research is focused on the comprehensive areas of • tribological-mechanical systems, • service strength and • acoustics. Bochumer Model www.ibaf-bochum.de IBAF, the Institute of Construction Machinery, Drive Systems and Materials Handling is one of the closest partners of the Research Group for Off-road machines. As a flexible industry based partner, IBAF works on projects based on day to day business and offers support well founded on specialists knowledge in the areas design, structural analysis, simulation and experimental development. Both institutions complement each other for the benefit of industry and university with their focus on day to day business as well as scientific research in an ideal way. How to find us This way, known methods and approaches from other areas can be applied to off-road machines, and research projects not directly connected to off-road machines can be integrated to realize synergy effects. Inside you will find a short description of our approaches to the areas of tribological-mechanical systems, service strength and acoustics. Push us to the limit! Contact Ruhr-Universität Bochum Research Group for Off-Road Maschines (Arbeitsgruppe Baumaschinentechnik) Building IB 1/127 Universitätsstrasse 150 D-44780 Bochum Germany Phone +49 234 32-26722 Fax +49 234 32-14161 Email: [email protected] By Car from A43 Exit at Bochum-Querenburg onto Universitätsstrasse (University Street) in the direction of Ruhr-Universität. Exit again at Uni-Ost (University East - second exit when coming from the Autobahn) and follow the road to the parking areas east of the building IC. By Car from Downtown Bochum Take Universitätsstrasse (University Street) exit UniMitte, Audimax, keep left and head for the visitor's parking. By Public Transportation Take U35 from central train station Bochum Hbf to Hustadt and get off the train at Ruhr-Universität and follow the directions on the map. Ruhr-Universität Bochum tribologicalmechanical systems The determination of the behaviour of tribological-mechanical systems - to improve the understanding of constructional units, for the identification of limits of stress, for optimization or for the creation of tribological simulations - is the goal of this comprehensive area. thermal behaviour mechanical behaviour tribological behaviour Against this background, the research group developed an applicable superordinate methodology in particular for sliding bearings and joints running in dry and boundary friction area. The system description includes internal causal directions. Mechanical Behaviour: surface pressure, velocity FE-contact analysis, reduced stiffness matrices out of FE, parametrical models, … Thermal Behaviour: temperature on sliding surface thermal FE-analysis, identified/reduced multibodymodels, parameter-open models, … Tribological Behaviour: friction coefficient, wear local approach, experimentally determined and parameterised, … The modelling needs an experimental verification – therefore the Research Group for Off-Road Machines performs a wide spectrum of tests on own test rigs for complete constructional units as well as for simple specimen. The competence shows itself also in the present key aspects of activity in this comprehensive area: simulation of wear for joints in chassis systems lifetime prediction of maintenance-free spherical plain bearings Service Strength Acoustics The proof of service strength and reliability of mechanical components is one of the major competences of the Research Group for Off-Road Machines. Independent of a specific task, the assessment of static and dynamic strength is always based on an integrated concept starting with the identification and quantification of the relevant loads or load combinations, followed by the calculation of the resulting stresses and strains, and concluded with the comparison with the corresponding limit states. Targeted development and optimization processes in the field of acoustics require an extensive system comprehension of the investigated machines which covers the complete mechanism of the noise generation including the excitation, the structure-born sound transmission and the airborne sound emission. Applied tools and assessment methods: modeling of beam-, area- and volume-shaped components application of rigid frame statics- and MBS-software tools for the determination of loads nominal and local stress concepts for the strength assessment; application of FEM-software for the determination of local stresses as a result of mechanical and thermal loads determination of limit states and execution of the proofs of competence according to current technical standards and specifications (e.g. FKM-Guidelines, DIN 743, EN 13001) development of methods to incorporate effects of wear and corrosion At present, the research work of the Research Group for Off-Road Machines in this field is composed of two joint research projects which are supported by the German Federal Ministry of Education and Research (BMBF) and the German Federal Ministry of Economy (BMWi). Several industrial companies as well as universities are involved in these projects. Subject of these projects is the assessment of service strength and reliability of mechanical plant components used for the production of crude oil and gas: identification of relevant components consideration of limit states of service strength (e.g. static and fatigue limits) as well as limit states of serviceability (e.g. deformations, temperature limits) derivation of parametrical models for the development of pumps and plants of higher power ratings, varying operating conditions and plant configurations consideration of the effects of production on-shore, offshore and in barely accessible areas development and implementation of methods to incorporate effects of wear and corrosion into the strength assessment In this context the Research Group for Off-Road Machines has developed a method for acoustic analysis especially for the assessment of highly complex machines and vehicles. The first step of this method is the construction of a global but nevertheless differentiated acoustic image of the machine in order to identify the relevant sound sources and the locations of sound emission. This image also allows for a characterization of the emission in the frequency range. The acquired system comprehension enables to derive targeted optimization and development approaches. This process is based on the classification of the sound sources in relation to their potential of optimization. Finally, in order to establish feasible solutions, not only the acoustic requirements but also the individual operating conditions are considered. Advantages of the method: systematic identification and assessment of the acoustic optimisation potential time-efficient development of feasible solutions for offroad machines specific suggestions for new product development cost reduction in the development process (e.g. less prototypes) parallel optimization and development process Research objectives on this field: Vibro-acoustic analysis and optimization of crawler-tracks: quantification of impact excitation determination of structure-born sound transmission and airborne sound emission development of approaches for the acoustic optimization of crawler tracks Acoustic optimization of driver cabins: experimentally supported analysis of the present acoustic state simulation-supported interior noise analysis of the cabin in order to derive optimized components and linkages of the components during the development process