Department of Machine and Industrial Product Design Contact person: Dr. Tibor Goda (

Department of Machine and Industrial Product Design2 GM research topics relating to this area : 8, 10, 65 LUBRICATION AND FRICTION PREDICTION Competence in: 1. Modeling of adhesion 2. Boundary lubrication (shear strength of the boundary layer) 3. Numerical modeling of fluid and mixed friction Geometrical sizes of the seal and the rod Material properties of the rubber seal (E,n) Sealed pressure (psealed) Rod speed (outstroke+instroke) Fluid viscosity at atmospheric pressure (m 0 ) Pressure viscosity coefficient (a) Combined surface roughness of the rod and the seal (s,R,h) Coefficient of friction at asperity contact (f) Length of the sealing zone (L) Number and coordinates of contact nodes Static contact pressure at the contact nodes (p sc ) Influence coefficient matrix for the contact nodes (I ij ) Static film thickness at the contact nodes (H s ) Initial guess for the film thickness (distance between mean surfaces at the given node) Contact analysis (Greenwood- Williamson contact model) Calculation of the flow factors Calculation of the truncated film thickness (h T ) Discretized Reynolds equation (linear algebraic equations) non-linearity induced by pressure dependent viscosity Calculation of the total pressure (p t =p fluid +p contact ) Calculation of seal deformation induced by hydrodynamic and contact pressure Calculation of leakage and friction force Contact pressure due to asperity contact (p contact ) Fluid pressure (p fluid ) Location of the full film and the cavitated regions Updated film thickness

LUBRICATION AND FRICTION PREDICTION Present research activity of the department in this field: EU FP6 research project „Knowledge-based Radical Innovation Surfacing for Tribology and Advanced Lubrication” (EU Project Reference NMP3-CT , References: [1] Kozma, M.: „Hydrodynamic and boundary lubrication of elastomer seals”, 19th International Conference on Fluid Sealing, Poitiers, France [2] Goda T. J.: "Numerical modelling of lubrication in reciprocating hydraulic rod seals„, Proceedings of sixth conference on mechanical engineering, ISBN , (2008) 4. Oil/grease lubricated sliding contact 5. Modeling of rheological behavior of lubricants

Department of Machine and Industrial Product Design4 GM research topics relating to this area : 31 RUBBER PHYSICS Competence in: 1. Modeling of the non-linear, time- and temperature-dependent material behavior of rubber and rubber-like materials 2. Characterization of the asphalt’s surface topography (Power Spectral Analysis, surface roughness measurements, etc.) 3. Contact modeling of rubber/ rough counterpart sliding pairs CONTACT MECHANICS, RUBBER FRICTION (SLIDING AND ROLLING), FE MODELLING

Department of Machine and Industrial Product Design5 RUBBER PHYSICS 4. FE modeling of hysteresis induced rolling and sliding resistance 5. FE modeling of hysteresis induced and friction related heat generation (thermo-mechanical coupled analysis) Present research activity of the department in this field: EU FP6 research project „Knowledge-based Radical Innovation Surfacing for Tribology and Advanced Lubrication” (EU Project Reference NMP3-CT , project.org) project.org References: [1] Goda, T.; Pálfi, L.; Váradi, K.; Garbayo, E.; Bielsa, J.M.: “FE prediction of the hysteretic component of rubber friction: importance of the Maxwell-parameters”, Fall Rubber Colloquium, (2008), pp. 128 [2] Felhős, D.; Xu, D.; Schlarb, A.K.; Váradi, K.; Goda, T.:”Viscoelastic characterization of an EPDM rubber and finite element simulation of its dry rolling friction”, EXPRESS POLYMER LETTERS, Vol. 2, No.3, (2008) pp CONTACT MECHANICS, RUBBER FRICTION (SLIDING AND ROLLING), FE MODELLING

Department of Machine and Industrial Product Design6 GM research topics relating to this area : 67 FE THERMAL MODELLING Competence in: 1. Transient and steady-state FE thermal modeling (heat partition, thermal contact resistance, contact conductive heat flux, etc.) 2. Stick-slip related thermal problems 3. Coupled thermo-mechanical analysis

Department of Machine and Industrial Product Design7 FE THERMAL MODELLING 4. Moving and distributed heat source models Present research activity of the department in this field: Hungarian National Scientific Research Foundation project: „Friction behaviour and failure mechanisms of polymer, elastomer, ceramic and composite structural components”, OTKA (NI 62729) References [1] Lestyán, Z.; Váradi, K.; Albers, A.: „Contact and thermal analysis of an alumina-steel dry sliding friction pair considering the surface roughness”, TRIBOLOGY INTERNATIONAL, Vol. 40, pp (2007) [2] Fekete, G.; Váradi, K.; Leali, M.; Bottarelli, F.: "Thermal FE analysis of a pneumatic cylinder„, Proceedings of sixth conference on mechanical engineering, ISBN , (2008)

Department of Machine and Industrial Product Design8 GM research topics relating to this area : 101 WEAR DETECTION AND SIMULATION Competence in: 1. FE wear simulation

Department of Machine and Industrial Product Design9 WEAR DETECTION AND SIMULATION Present research activity of the department in this field: Hungarian National Scientific Research Foundation project: „Friction behaviour and failure mechanisms of polymer, elastomer, ceramic and composite structural components”, OTKA (NI 62729) References: [1] Kónya, L.; Váradi, K.: „Wear simulation of a polymer-steel sliding pair considering temperature- and time-dependent material properties”, in Friedrich, K.; Schlarb, A.K. (editors) „Tribology of Polymeric Nanocomposites”, TRIBOLOGY AND INTERFACE ENGINEERING SERIES, No. 55, Elsevier, (2008) ISBN Modeling and interpretation of typical wear mechanisms 3. Characterization of worn surfaces