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Loads Cascading in the Frequency Domain
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 03, 2018 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
A previous SAE paper (ref. 1) did a comparative study of automotive system fatigue models processed in the time and frequency domain. A subsequent paper (ref. 2) looked at relative random analysis under base shake loading conditions. This paper proposes to merge these two analysis procedures to implement a new “Loads Cascading” procedure.
The objective of this paper will be to show how loads (accelerations, displacements, forces) can be cascaded (transferred) from input load position such as road load data (RLD) body loads to some internal location, for example a battery pack location. Also note that the response from one “module” could form the input to another, therefore, once the loadings are in the frequency domain, the possibility exists to “cascade” the loads through a system. For example, from the chassis, to the subframe to attached components.
The term “cascading” is used to represent a process (in the frequency domain) where an input is related to an output via a set of system properties (transfer functions). In a conventional analysis, the input might be road load data (forces) applied near the wheels to the body of, for example, a trailer. And, in a conventional analysis, the output might be the stress distribution that will be used for a fatigue life calculation. But with loads cascading the additional requested output could be the same as the input (e.g. force) or another variable used as a loading function to a secondary system, like displacement or acceleration. And the additional advantage is that this kind of loads cascading can be done in parallel with a conventional stress analysis with no additional computational expense. In this way, the loads can be cascaded to multiple required internal locations.
Examples of internal locations could be subframes, battery packs, spare wheel locations, etc. The same truck frame model (or similar) as used in the previous 2016 SAE paper (ref. 1) will be used for the loads cascading analysis.
CitationBishop, N., Sweitzer, K., Ferreira, W., Cardoso, V. et al., "Loads Cascading in the Frequency Domain," SAE Technical Paper 2018-01-0138, 2018, https://doi.org/10.4271/2018-01-0138.
Data Sets - Support Documents
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- Ferreira , W.G. , Meehan , T.S. , Bishop , N. , and Cardoso , V.M. Comparative Study of Automotive System Fatigue Models Processed in the Time and Frequency Domain SAE Technical Paper 2016-01-0377 2016 10.4271/2016-01-0377
- Datta , S. , Bishop , N. , Sweitzer , K. , and Atkins , A. Simultaneous Durability Assessment and Relative Random Analysis Under Base Shake Loading Conditions SAE Technical Paper 2017-01-0339 2017 10.4271/2017-01-0339
- Bishop , N.W.M. and Sherratt , F. Finite Element Based Fatigue Calculations NAFEMS 2000
- Lee , Y.-L. , Barkey , M.E. , and Kang , H.-T. Metal Fatigue Analysis Handbook. Practical Problem-Solving Techniques for Computer-Aided Engineering Butterworth-Heinemann, Elsevier 2012
- Landgraf , R.W. Fatigue Technology in Vehicle Development Proceedings of SAE Brasil-International Conference on Fatigue São Paulo Society of Automotive Engineers 2001 21 29
- Haiba , M. et al. Review of Life Assessment Techniques Applied to Dynamically Loaded Automotive Components Computers and Structures 80 39 53 2002
- Conle , F.A. Durability Analysis under Complex Multiaxial Loading SAE Technical Paper 871969 1987 10.4271/871969
- Conle , A. et al. Computer-Based Prediction of Cyclic Deformation and Fatigue Behavior Low Cycle Fatigue 1988
- Conle , F.A. and Mousseau , C.W. Using Vehicle Dynamics Simulations and Finite-Element Results to Generate Fatigue Life Contours for Chassis Components International Journal of Fatigue 3 195 205 1991
- Conle , F.A. and Chu , C.-C. Fatigue Analysis and the Local Stress-Strain Approach in Complex Vehicular Structures International Journal of Fatigue 19 1 317 323 1997
- Chu , C.-C. Multiaxial Fatigue Life Prediction Method in the Ground Vehicle Industry International Journal of Fatigue 19 1 325 330 1997
- Bishop , N. , Kerr , S. , Murthy , P. , and Sweitzer , K Time vs Frequency Domain Analysis for Large Automotive Systems SAE Technical Paper 2015-01-0535 2015 10.4271/2015-01-0535
- Bishop , N. , Kerr , S. , and Murthy , P. Advances Relating to Fatigue Calculations for Combined Random and Deterministic Loads SAE Technical Paper 2014-01-0725 2014 10.4271/2014-01-0725
- Palmer , T. and Bishop , N. Solver Embedded Fatigue SAE Technical Paper 2014-01-0904 2014 10.4271/2014-01-0904
- Costa , E. , Bishop , N. , and Cardoso , V. Frequency FE-Based Weld Fatigue Life Prediction of Dynamic Systems SAE Technical Paper 2017-01-0355 2017 10.4271/2017-01-0355
- Gannamani , R. , Gupta , A. , Bishop , N. , Caserio , A. Sine on Random Vibration Fatigue NAFEMS World Congress Stockholm 2017
- Nienkemper , R. and Bishop , N. Simultaneous Durability Assessment and Relative Random Analysis Under Base Shake Loading Conditions NAFEMS World Congress Stockholm 2017
- Udayakumar , G. , Murthy , P. , Bishop , N. , Moolam , R. Creating Accurate Surrogate and/or Accelerated Loads for Known Models or Structural Systems Types NAFEMS World Congress Stockholm 2017
- Sweitzer , K.A. 1994
- Rice , R.C. , Society of Automotive Engineers, Fatigue Design and Evaluation Committee SAE Fatigue Design Handbook SAE-Society of Automotive Engineers, Inc. Warrendale 1997
- Slavic , J. et al. Frequency-Domain Methods for a Vibration-Fatigue-Life Estimation-Application to Real Data Proceedings of International Conference on Noise and Vibration Engineering (ISMA2012-USD2012) Leuven 2012
- Larsen , C.E. and Irvine , T. A Review of Spectral Methods for Variable Amplitude Fatigue Prediction and New Results 3rd International Conference on Material and Component Performance under Variable Amplitude Loading Procedia Engineering 243 250 2015
- Bishop , N. and Sherratt , F. Fatigue Life Prediction from Power Spectral Density Data. Part 1, Traditional Approaches and Part 2, Recent Developments Env. Eng. 2 1989 An Introduction to Random Vibrations, Spectral & Wavelet Analysis
- Bishop , N. , Lack , L. , Li , T. , and Kerr , S. Analytical Fatigue Life Assessment of Vibration Induced Fatigue Damage Proceedings of MSC World Users Conference Universal City 1995
- Thesing , T. , and Bishop , N. Modern Methods for Random Fatigue of Automotive Parts SAE Technical Paper 2016-01-0372 2016 10.4271/2016-01-0372
- Bishop , N. , Murthy P. , and Sweitzer , K. Advances Relating To Fatigue Calculations For Combined Random and Deterministic Loads 13th International ASTM/ESIS Symposium on Fatigue and Fracture Mechanics (39th National Symposium on Fatigue and Fracture Mechanics) Jacksonville 2013
- Sweitzer , K.A. , Bishop , N.W.M. , and Genberg , V.L. Efficient Computation of Spectral Moments for Determination of Random Response Statistics International Conference on Noise and Vibration Engineering-ISMA Leuven 2004