After the moving loads have been defined, define one or more moving-load cases that assign the vehicles classes to paths. The Load Case Data - Moving Load form is used to view and change the definition of a moving-load load case.
Load Case Name edit box. Use the name shown or type a new name in this edit box. It should be unique among all load cases of all types. Click the Set Def Name button to apply the default load case name.
Notes Modify/Show button. Click this button to access the Load Case Notes form. Use that form to add notes to the file concerning this load case.
Design button. Click this button to access the Design Load Type form. Choose Program Determined, or User Specified and then a design type from the drop-down list. Design load types are used in creating automatic design load combinations.
Stiffness to Use Choose to solve for the response using the stiffness of the unstressed structure (i.e., the Zero Initial Conditions - Unstressed State option), or at the end of a nonlinear static or nonlinear direct-integration time-history analysis case (i.e., the Stiffness at End of Nonlinear Case option and drop-down list). See Stiffness to Use for more information. If you don't know what to do, choose the Zero Initial Conditions - Unstressed State option.
Loads Applied Apply loads by specifying one or more paths in which a vehicle class may operate. Every permutation of vehicle classes operating in paths that is permitted by the entries in this table will be considered in the analysis.
Assign Number display box. As loads are defined, the program enters an assignment number in this display box.
Vehicle Class drop-down list. Choose the vehicle class name, which was defined using the Vehicle Class Data form.
Scale Factor edit box. Enter a scale factor that multiplies the load for all vehicles in the class.
Min Loaded Paths edit box. Enter the minimum number of paths that must be occupied by the vehicle class. This is usually zero.
Max Loaded Paths edit box. Enter the maximum number of paths that may be occupied by the vehicle class. A value of zero indicates all paths.
Add button. To add a live load to the set of applied loads, enter the vehicle class and other parameters at the top of the table, then click the Add button. After clicking the Add button, use the Add-> and <-Remove buttons in the "Paths Loaded for Assignment {Number}" area of the form to create a list in the Selected Paths column that indicates all of the paths in which this vehicle class is allowed to operate. All permutations will be considered for the paths that are between the minimum and maximum number of allowed loaded paths.
Modify button. To modify a live load in the set of applied loads, click on the load in the table to select it, make any changes to the vehicle class and other parameters at the top of the table, or to the list of loaded paths, then click the Modify button.
Delete button. To remove a live load from the set of applied loads, click on the load in the table to select it, then click the Delete button.
Paths Loaded display box. The program will display All, Some, or None in this column to specify if paths are involved in the applied load assignment. Use the following list boxes and buttons to modify the path assignments to the applied load.
List of Path Definitions. The paths defined for the model are listed in this list box.
Selected Path Definitions. The paths to be used in a particular load are shown in this list box.
Add and Remove buttons. Use these buttons to add paths to or remove paths from an applied load. Highlight the load in the Loads Applied area (e.g., click on the Assign Number), highlight a path(s) in the List of Defined Paths display box and click the Add button to move the selected path(s) into the Selected Paths display box, which adds the path(s) to the applied load. To remove a path(s) from the applied load, highlight the load in the Loads Applied area, highlight a path(s) in the Selected Paths display box and click the Remove button to move the selected paths into the List of Defined Paths list box, which removes the path(s) from the applied load.
Multi-Path Scale Factors parameter. For each Number of Loaded Paths, enter any Reduction Scale Factors that may apply. This does not apply to any specific paths, but rather to combinations of loaded paths. For example, you may want to set the scale factor to 1 for one or two loaded paths, to 0.9 for three loaded paths, and to 0.75 for four or more loaded paths. These factors will be automatically applied when forming the various permutations of vehicle classes on the paths. Highlight data in the display list, enter a revised Reduction Scale Factor in the edit box, and click the Modify button to change a scale factor.
See Also
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Access the Load Case Data - Moving Load form as follows:
Note: To analyze for vehicle live load, first define a path(s), a vehicle(s), vehicle class(es), a moving load(s) and set the type of moving load results to be saved.
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