## Card 44 - TIRMU Tables: Veh1

The Optional TIRMU inputs permits the simulation of individual tires which have drag factors different than the nominal MU (i.e., metal gouging, etc.). If entered as 0.0, program assumes default value of 1.0 (normal).A value of TIRMU of 0.86 would reduce the effective friction coefficient for a tire from a nominal of 0.70 to 0.60. The nominal friction coefficient is determined for an individual wheel by either the friction zone as specified on input card 12 or by a polygon friction zone specified on card(s) 30,31,32.

Card(s) 44,49 permit the inputs for the Tirmu tire cornering stiffness as time history tables. This permits varying the tire cornering stiffness and/or tire friction factor multipliers during a simulation run (e.g., to simulate a tire deflating and/or rim gouging).

The first card for each input table is the table header card which describes the size and format for the input  tables to follow.

 TBTirmu1 TETirmu1 TINCT1 NTBLT1 VARINC 44

 Card:  Field Variable Description Original Units Default Units Metric Units Optional TIRMU (TIRe friction MUltiplier) Table Inputs for V1 The control inputs for TIRMU Friction multiplier for vehicle No. 1 are entered as time history tables of Friction Factor as a function of time on card(s) 44. The first card for each TIRMU table is the table header card which describes the size and format for the input tables to follow. 44:1 TBTirmu1 Initial time for V1's inputs. Seconds 44:2 TETirmu1 End time for V1's inputs Seconds 44:3 TINCT1 Time increment for TIRMU inputs for V1. One value for TIRMU is input  for each increment, so the size of TINCT1 determines the detail with which the TIRMU Variations can be described by the mathematical model.  NOTE: If field 6 (VarInc, Option Variable increment input) is set=1, then the definition of this variable is for the number of table inputs. Maximum 50. Seconds 44:4 NTBLT1 Normally = 0.0. If < 0.0, the program reads in and ignores the TIRMU tables included following card #44.  (This option is to permit de-activating tables without having to delete the data in the tables.) 44:5 Not used 44:6 VARINC (optional) Set =1.0 to indicate Variable time increment Table inputs. Field 4 is then used to indicate the number of inputs in the table. The Table Header card is followed by tables containing the values for the TIRMU for Vehicle No. 1: RF, LF, RR &  LR tires  (and RRR & LRR for trailer option), one set of values per card,  and up to 50 table values. The format for the tables is as follows: (n is a sequence number starting at 1) Time Tirmu1RF Tirmu1LF Tirmu1RR Tirmu1LR RRR1 LRR1 n 44

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Card 49 - TIRMU Tables: Veh2