1st International Conference on Modelling and Simulation on Engineering, Science and Technology (ICOMSEST) - Kuala Lumpur - Malaysia (2019-02-24)

Modeling and Simulation of Temperature in Polymer Based Tribo-logical Systems
Modeling and Simulation of Temperature in Polymer Based Tribo-logical Systems A. K. Schlarb1,2,3*, N. Ecke1, J. Höller4, J. Niedermeyer5, P. Klein4 1Chair of Composite Engineering (CCe), Technische Universität Kaiserslautern (TUK), Kaiserslautern, Germany 2Research Center OPTIMAS, Technische Universität Kaiserslautern (TUK), Kaiserslautern, Germany 3Qingdao University of Science & Technology (QUST), Qingdao, China 4Fraunhofer Institute for Industrial Mathematics (ITWM), Kaiserslautern, Germany 5Statistics group, Technische Universität Kaiserslautern (TUK), Kaiserslautern, Germany *Corresponding Author: Phone: + 49 631 205 5116; Email: alois.schlarb@mv.uni-kl.de Abstract: Polymer materials are gaining popularity in slide bearing applications due to their low mass and beneficial self-lubrication and damping properties. At the same time, the trend toward compact design causes increased specific loads. Therefore, as a partner in tribological sys-tems, plastics are increasingly being filled with glass or carbon fibers, submicron inorganic fillers, and internal lubricants such as graphite, polytetrafluoroethylene (PTFE) or molyb-denum sulfide (MoS2) in order to improve their tribological performance. These hybrid materials have proven to be excellent solutions for tribological application at high external loads. [1] However, especially the high temperatures that go along with high sliding speeds have a strong impact on the choice of the polymer matrix materials. Since measurement of the temperature is nor feasible in the sliding interfaces, there are numerous approaches to de-termine the temperature in the tribological interaction plane using modeling and simulation. Figure. 1: Heat flow in a tribopair First attempts go back to Blok [2] and Jaeger [3] published in the first half of the last cen-tury. Based on this work numerous researchers [4-12] tried to improve the description of temperature in the critical interaction area. Nowadays, finite element methods are used by default to solve heat and mass transfer problems. Even though first attempts have been published [13], currently there is no relia-ble and simple method for denying the three dimensional temperature distribution in a tribological system, where a polymer based hybrid material is used as a partner in the slid-ing pair. The objective of our present contribution is the comparison of different simulation ap-proaches in terms of temperature assessment in a dry sliding polymer/metal system. The presentation is divided into three parts. First, an evaluation of the average sliding surface temperature calculated using different analytical methods is presented. However, this method only results in the representation of a mean sliding surface temperature. Therefore, in the second step, we propose an approach using finite elements and a numerical simula-tion. Hereby, local temperatures in the sliding interface can be determined as well as the spatial temperature distribution in the entire system. A challenge in this procedure is the determination of the thermal material properties. From our work, it can be concluded that the analytical approaches used to estimate the temperatures in tribological contacts are only of limited use. In particular, the spatial resolu-tion of the thermal situation is possible only in a rudimentary way even with simple geome-tries. In addition, some simplifications have to be made within the framework of analytical modeling, such as neglecting convective heat flows and lateral heat conduction. Using numerical simulations, the prediction of the tree-dimensional temperature distribu-tion in a tribological system is feasible. In order to obtain valid results, such simulations require accurate material models and boundary conditions as an input. The main issue with using this method is that a large number of material data are often not available in litera-ture, especially if multiphase/hybrid materials are concerned. In order to solve this, we pro-pose different methods for homogenizing the material data based on the properties of the individual components of a high performance polymer based tribocompound. Figure. 2: a) Randomized RVE, b) Temperature distribution in the (half) body 1, c) Temperatures at different paths in the body 1 Lieterature [1] Friedrich K, Zhang Z, Schlarb A.K.: Effects of various fillers on the sliding wear of polymer composites. Compos Sci Technol 2005;65:2329–43. doi:10.1016/J.COMPSCITECH.2005.05.028. [2] Blok, H.: Theoretical study of temperature rises at surfaces of actual contact under oiliness conditions. Proc. Inst. Mech. Eng., General discussion on lubrication & lubri-cants, 2 (1937), S. 222-231 [3] Jaeger, J.C.: Moving Sources of Heat and the Temperature at Sliding Contacts. Pro-ceedings of the Royal Society of New South Wales, 76 (1942), S. 203-224 [4] Archard, J.F.: The temperature of rubbing surfaces. Wear, Volume 2 (1959), S. 438-455, DOI: 10.1016/0043-1648(59)90159-0 [5] Greenwood, J.A. An interpolation formula for flash temperatures. Wear 150 (1992), S. 153-158, DOI: 10.1016/0043-1648(91)90312-I [6] Kuhlmann-Wilsdorf, D. Demystifying flash temperatures I. Analytical expressions based on a simple model. Materials Science and Engineering, 93 (1987), S. 107-118, DOI: 10.1016/0025-5416(87)90417-4 [7] Kuhlmann-Wilsdorf, D. Demystifying flash Temperatures II. First-order approxima-tion for plastic contact spots. Materials Science and Engineering, 93 (1987), S. 119-133, DOI: 10.1016/0025-5416(87)90418-6 [8] Tian, X.; Kennedy, F.E.: Maximum and average flash temperatures in sliding contact. Journal of Tribology, 116 (1994), S. 167-174, DOI: 10.1115/1.2927035 [9] Carslaw, H.S.; Jaeger, J.C.: Conduction of heat in solids. Oxford University Press, London, 1959 [10] Ashby, M.F.; Abulawi, J.; Kong, H.S.: Temperature maps for frictional heating in dry sliding. Tribology Transactions, 34 (1991), S. 577-587, DOI: 10.1080/10402009108982074 [11] Künkel, R.: Auswahl und Optimierung von Kunststoffen für tribologisch beanspruchte Systeme. Dissertation, Universität Erlangen-Nürnberg, 2005 [12] Schlarb, A.K.; Zvonkina, I.J.; Prado, L.; Schulte, K.: Performance of CNT-reinforced epoxy resins in tribological applications. IUMRS-ICA 2010, Qingdao, 2010 [13] Schott, M.; Schlarb, A.K.: Simulation des thermischen Haushalts von Kunst-stoff/Metall-Gleitpaarungen mittels FEM. Tribologie + Schmierungstechnik, 65. Jahr-gang 1/2018 Keywords: Analytical modelling; Computational modelling; Finite Element Analysis; Thermal properties; Tribology
Professor Alois K. Schlarb, Mr. Nicholas Ecke, Dr. Johannes Hoeller, Mr. Jan Niedermeyer