SMAC/HVOSM tire model analytical formulations
Posted: Mon Jun 22, 2009 4:08 pm
Q: I am doing a study of the tire force models used in various vehicle dynamic simulation programs. The McHenry write-up on Cornering Stiffness from your accident reconstruction seminar sketches out the form of the m-smac tire model but does not give details. For example, how are the lateral stiffness and sliding friction specified simultaneously? The non-dimensional equation has no parameters. Can you supply me with a description of the model's mathematical formulas?
A: Are you planning on a detailed technical presentation of the various tire models or merely an overview?
I would suggest you review the two tire models developed for the HVOSM-RD2 and the HVOSM-VD2 models by Raymond R. McHenry. The source documents contain a plethora of information on the analytical models, etc.
The HVOSM-76 report by Segal (available on NTIS, see below) is a 4 volume collection of the work and includes most of the pertinent information (it is basically a republication of the earlier 10 volumes of work by McHenry, etc. on HVOSM development).
Please also note that McHenry Consultants did additional development on the RD2 tire model, particularly the tire saturation and friction aspects, and it has been incorporated as part of rollover and pavement shoulder research which we performed and published with Midwest research, Calspan, HSRC, etc. Please see the McHenry publications page under the subject McHenry papers on HVOSM - Highway Vehicle Object Simulation Model for documents related to that research.
The model used in the SMAC model is a simplification of the HVOSM tire models.
The earlier SMAC research reports contain the analytical models, etc. Please also see the SMAC tire model analytical equations.
Two papers which include discussion of the tire model (non-dimensional side-slip, etc.) that McHenry 1st implemented in HVOSM and then in SMAC are:
A: Are you planning on a detailed technical presentation of the various tire models or merely an overview?
I would suggest you review the two tire models developed for the HVOSM-RD2 and the HVOSM-VD2 models by Raymond R. McHenry. The source documents contain a plethora of information on the analytical models, etc.
The HVOSM-76 report by Segal (available on NTIS, see below) is a 4 volume collection of the work and includes most of the pertinent information (it is basically a republication of the earlier 10 volumes of work by McHenry, etc. on HVOSM development).
Please also note that McHenry Consultants did additional development on the RD2 tire model, particularly the tire saturation and friction aspects, and it has been incorporated as part of rollover and pavement shoulder research which we performed and published with Midwest research, Calspan, HSRC, etc. Please see the McHenry publications page under the subject McHenry papers on HVOSM - Highway Vehicle Object Simulation Model for documents related to that research.
The model used in the SMAC model is a simplification of the HVOSM tire models.
The earlier SMAC research reports contain the analytical models, etc. Please also see the SMAC tire model analytical equations.
Two papers which include discussion of the tire model (non-dimensional side-slip, etc.) that McHenry 1st implemented in HVOSM and then in SMAC are:
- "Motions of Skidding Automobiles", Radt & Milliken, SAE 60133 (it is on the SAE Accident Reconstruction CD as we requested they add it).
- The Radt & Milliken paper is the extension of the "Fiala tire model".
- The paper is further implementation and the 'putting it all together' tire model into the HVOSM computer model and then portions of which were later implemented into SMAC.
- HVOSM: "Highway-Vehicle Object Simulation Model - 1976","Volume I - User's Manual", (PB-267401) "Volume II - Programmer's Manual" (PB-267402) "Volume III - Engineering Manual - Analysis" (PB-267403) "Volume IV - Engineering Manual - Validation" (PB-267404); SET of 4 volumes: PB267400 Segal, D. J.. http://www.ntis.gov/search/index.aspx