This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Bulkhead Loading Calculation of an Aluminum Engine Block Coupled with a Rotating Crankshaft through Elastohydrodynamic Bearings
Technical Paper
2007-01-0267
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
During a new engine development program, or the adaptation of an existing engine to new platform architectures, testing is performed to determine the durability characteristics of the basic engine structure. Such testing helps to uncover High Cycle durability-related issues that can occur at the bulkhead walls as well as cap bolt thread areas in an aluminum cylinder block. When this class of issues occurs, an Elastohydrodynamic (EHD) bearing simulation capability is required.
In this study, analytical methods and processes are established to calculate the localized distributed load on the bulkhead. The complexity in performing a system analysis is due to the nonlinear coupling between the bearing hydrodynamic pressure distribution and the crankshaft and block deformation. A system approach for studying the crankshaft-block interaction requires a crankshaft flexible body dynamics model, an engine block assembly flexible body dynamics model and a main bearing lubrication model. Such a system model is presented in this paper by employing multi-body dynamic system simulation to capture the dynamic characteristics from the engine durability test set-up. By using a multi-body code, DADS, with hydrodynamic (HD) bearings to couple the interaction between the flexible crank and flexible block, the resultant bearing loads and moments were calculated. Then, employing a GMPT EHD code, FLARE, the distributed nodal bearing forces were extracted from the complex interactions between the lubricant film and the solid surface by solving the Reynolds' equation.
All the detailed bearing parameters are taken into account, such as split line relief and eccentricity, upper oil groove, rotating journal oil holes, and asperity contact. Using this approach, a V8 engine was illustrated in this paper. The design parameters such as the location of oil holes in the journal of crank were studied and summarized in this paper. Finally, stress results in the single bulkhead #4 with the distributed bearing reaction EHD forces, head bolt preload and thermal deformation due to different material are also summarized in this paper.
Recommended Content
Citation
Du, H. and Shi, F., "Bulkhead Loading Calculation of an Aluminum Engine Block Coupled with a Rotating Crankshaft through Elastohydrodynamic Bearings," SAE Technical Paper 2007-01-0267, 2007, https://doi.org/10.4271/2007-01-0267.Also In
New SI Engine and Component Design and Engine Lubrication and Bearing Systems
Number: SP-2093; Published: 2007-04-16
Number: SP-2093; Published: 2007-04-16
References
- Boedo, S. Booker, J.F. Wilkie, M.J. “A Mass Conserving Modal Analysis for Elastohydrodynamic Lubrication,” Proceeding 21st Leeds-Lyon Symposium on Tribology Leeds, England September 6-9 1995 513 523
- Boedo, S. Booker, J.F. “Surface Roughness and Structural Inertia in a Mode-Based Mass-Conserving Elastohydrodynamic Lubrication Model,” ASME Journal of Tribology 119 1997 449 455
- Boedo S. Booker J.F. “A Mode-Based Elastohydrodynamic Lubrication Model with Elastic Journal and Sleeve,” ASME Journal of Tribology 122 2000 94 102
- Du, H.Y. “Simulation of Flexible Rotating Crankshaft with Flexible Engine Block and Hydrodynamic Bearings for a V6 engine” SAE Paper No. 1999-01-1752 1999
- Ebrat, O. Mourelatos, Z. Hu, K. Vlahopoulos, N. Vaidyanathan, K. “Structural Vibration of an Engine Block and a Rotating Crankshaft Coupled Through Elastohydrodynamic Bearings” SAE Paper No. 2003-01-1724 2003
- Hanahashi, Mi. Katagiri, T. Okamoto, Y. “Theoretical Analysis of Engine Bearing Considering Both Elastic Deformation and Oil Film Temperature Distribution” SAE Paper No. 2001-01-1076 2001
- Xu, H. Wang, D. Poynton, W. “Effects of Oil Groove Locations on the Performance of the Big End Bearing of a Medium Speed Diesel Engine” SAE Paper No. 1999-01-1316 1999
- Thomas, S. Maassen, F. “A New Transient Elastohydrodynamic (EHD) Bearing Model Linkable to ADAMS” SAE Paper No. 2001-01-1075 2001
- Shabana, A. “Substructure Synthesis Method for Dynamic Analysis of Multibody Systems,” Computers & Structures 20 4 1985 737 744
- Craig, R. R. Bampton, M. C. C. “Coupling of Substructures for Dynamics Analysis,” AIAA Journal 6 7 July 1968 1313 1319
- Knoll, G. Peeken, H. Troppmann, Ph. Zeischka, J. Maessen, F. “The Dynamic Motion of Elastic Crankshaft Considering Main Bearing Stiffness and Hydrodynamic Reaction Force” 6th Internationaler Kongress: Berechnung im Automobilbau 21-23 September 1992 Wurzburg
- Childs, D.W. Moes, H. van Leeuwen, H.J. “Journal Bearing Impedance Descriptions for RotorDynamic Applications,” ASME Journal of Lubrication Technology 1977 198 211
- LaBouff, G.A. Booker, J.F. “Dynamically Loaded Journal Bearings: A Finite Element Treatment for Rigid and Elastic Surfaces,” ASME Journal of Tribology 107 1985 505 515
- Booker, J.F. “Dynamically-Loaded Journal Bearings: Numerical Application of the Mobility Method,” ASME Journal of Lubrication Technology 93 Jan. 1971 168 176