Momentum – Low Speed Collisions

Overview: Computes the Closure Speed and DeltaV data in Low Speed Collisions.

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 Momentum block and click on Low Speed Collisions 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 an .LSC 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:

· Friction (External) – Sum of the External Friction Forces

· DeltaT – Time of the Collision

· Restitution (e) – Restitution value for the Collision

· Weight 1 – Weight of Vehicle 1

· Weight 2 – Weight of Vehicle 2

· Delta V1 – Change of Velocity for Vehicle 1

Or

· Delta V2 – Change of Velocity for Vehicle 2

Entry of specific (known) data in the data boxes sufficient to generate an answer causes output information to appear in the Data frame. As the input data is changed, the output data is automatically updated without the need to tell the program to update the output.

Output:

The output from this module consists of an acceleration/deceleration factor and rates as well as the Closure velocities of the vehicles expressed in both the primary and secondary output configurations as selected in the Setup > REC-TEC menu.

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

· Save .LSC 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.LSC” of the data at the close of this module or the close of the program.

· Formulae* - Toggles a frame displaying the formulae for computing the unknowns in this module. In addition to the basic formulae, the frame shows intermediate steps with the actual input data shown in the computation.

· Delta V1 – Constant Vc – Displays a table showing a change in Delta V1 for changes in the values of Delta T and Restitution (e).

· Delta V2 – Constant Vc – Displays a table showing a change in Delta V2 for changes in the values of Delta T and Restitution (e).

· Vclosure – Constant V1 – Displays a table showing a change in the Closure Velocity for changes in the values of Delta T and Restitution (e) based on a constant value for V1.

· Vclosure – Constant V2 – Displays a table showing a change in the Closure Velocity for changes in the values of Delta T and Restitution (e) based on a constant value for V2.

· 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.