Miscellaneous – Weight Shift 

 

Overview:  Computes Passenger Vehicle, Straight Truck, Bus or other non-articulated Vehicle three-axis center of gravity based on information about vehicle and weights on the wheels when level and then raised.  This module will also compute rollover speeds and critical speed of curve data.

 

Entry into Module:

 

This module of the program is normally entered by clicking on the REC-TEC block in the upper left of the REC-TEC Window causing the drop-down menu to appear.  Place the cursor on the Miscellaneous block and click on Weight Shift on the sub-menu to initiate this module.

 

Under certain circumstances, the user may choose to use the Files block instead of the drop-down menu approach.  Selecting any file with a .WST extension in the Dialog box accessed from either the Open Single File or Open Multiple Files block opens this module.

 

Selecting AutoLoad [ON] from either the Setup Menu or the AutoLoad Icon on the upper right side (third line) of the REC-TEC Window automatically loads the scenario that was on the screen when the module was closed, either individually, or when the program was closed.  With AutoLoad [OFF] on the main REC-TEC Window, modules will start without loading a file.

 

Data Entry:

 

This module contains the following data entry blocks within the leftmost frame:

 

Rotation Factor

 

·             Wheelbase – Vehicle Wheelbase

·             Track – Vehicle Track

 

·             Chord – Required with Middle Ordinate

·             Middle Ordinate – Required with Chord

 

OR

 

·             Radius – Radius of Curve

 

·             Mu – Surface Friction

·             Superelevation – Tangent of Angle (Adjustment in direction of Striation Marks)

 

Deceleration Data:

 

·             Drag Fctor (LR) – Drag Factor corrected for grade

·             Drag Fctor (LF) – Drag Factor corrected for grade

·             Drag Fctor (RF) – Drag Factor corrected for grade

·             Drag Fctor (RR) – Drag Factor corrected for grade

 

Distance:

 

·             Distance (LR) – Deceleration Distance of Wheel

·             Distance (LF) – Deceleration Distance of Wheel

·             Distance (RF) – Deceleration Distance of Wheel

·             Distance (RR) – Deceleration Distance of Wheel

 

Level:   (Enter Zero (0) to Manually Place CG)

 

·             Axle Height – Level (Measured from Surface)

 

·             Weight (LR) – Weight on Wheel when Level

·             Weight (LF) – Weight on Wheel when Level

·             Weight (RF) – Weight on Wheel when Level

·             Weight (RR) – Weight on Wheel when Level

 

Raised:   (Enter Zero (0) to Manually Place CG)

 

·             Axle Height – Raised  (Minimum of 30 inches)

 

·             Weight (LF) – Weight on Wheel when Rear Axle Raised

·             Weight (RF) – Weight on Wheel when Rear Axle Raised

 

OR

 

·             Weight (LR) – Weight on Wheel when Front Axle Raised

·             Weight (RR) – Weight on Wheel when Front Axle Raised

 

Manual Placement of CG

 

·             Vertical – CG Vertical from Road Surface

·             Lateral – CG Lateral (from Left)

·             Longitudinal – Longitudinal (from Rear Axle)

·             Vehicle Weight – Total Weight of Vehicle

 

 

Output:

 

·             CG Lat – Lateral CG (Entered or Computed)

·             CG Long – Longitudinal CG (Entered or Computed)

·             CG Vert – Measured from Surface

 

·             WtSftd – Weight shifted to leading Tires

 

 

·             Weight (LR) – Weight on Wheel when Level

·             Weight (LF) – Weight on Wheel when Level

·             Weight (RF) – Weight on Wheel when Level

·             Weight (RR) – Weight on Wheel when Level

 

Deceleration

 

·             D Factor – Drag Factor

·             Rate – Rate of Acceleration (Primary)

·             Rate – Rate of Acceleration (Secondary)

 

·             Braking – Braking %

 

·             Speed – Speed (Primary)

·             Speed – Speed (Secondary)

 

Critical Speed of Curve

 

·             Angle – Subtended Angle

·             Radius – Entered or Computed

·             (f)riction – Entered

 

Arc

 

·             Time – Time on Arc at Constant Speed

·             Distance – Distance on Arc

·             Speed – Speed (Primary)

·             Speed – Speed (Secondary)

 

Roll Over (Left or Right)

 

·             f(Critical) – if f lower than f(Crt) Something caused Tripping – No Rollover

·             Speed – Speed (Primary)

·             Speed – Speed (Secondary)

 

Options: 

 

Several Command Buttons appear in a frame located at the lower right corner of the module Window.  The Command Buttons allow the user to engage options including the option to Open and Save the data required to generate the scenario shown on the screen at the time the file was saved. 

 

·             Open .WST File – Calls up a Dialog box, which Opens any pre-existing .WST file and displays the output results.

 

·             Save .WST File – Calls up a Dialog box, which Saves data on the screen to files with any user-selectable filenames.  This is independent of the automatic saving as “LastFile.WST” of the data at the close of this module or the close of the program.

 

·             Formulae – Opens a word processor (set by the user in Setup) with a file showing the basic formulae used in this mdoule of the program.  While the user may add to or modify the information in this file, it does not change the formulae imbedded into the program.

 

·             N – This button toggles a graphical number pad on the screen that can be used to enter data into the input boxes without using your keyboard number pad.  This may be useful for presentations as data entry can be accomplished using a wired/wireless mouse.