Creating and using loads


An analysis study requires that at least one load or one constraint is defined. Solid Edge Simulation provides geometry-based load types and a variety of methods for placing these loads on your FEA model.

Using loads

A static analysis calculates the effects of steady loading conditions on a structure, while ignoring the effects of loads that vary with time. Common loading conditions in a linear static analysis include:

  • Externally applied forces and pressures—An example of a static force is a building's dead load, which is comprised of the weight of the building, plus the weight of offices, equipment, and furniture. This dead load is often expressed in terms of lb/sq ft or N/sq m. Such loads are often defined using a maximum expected load with some factor of safety applied.

  • Steady-state inertial forces (such as gravity or rotational velocity)

  • Imposed displacements—An enforced displacement can be a static load, such as when a building foundation that may settle somewhat, inducing static loads.

  • Temperatures (for thermal strain)—For example, a steady-state temperature field. The applied temperatures cause thermal expansion which, in turn, causes induced forces.

Example:

A linear static study of a wall-mounted pressurized container with nozzle connections to other pipes might include the following loads:

  • Internal pressure

  • Support forces

  • Temperature

  • Forces applied at each nozzle location

  • Beam bending moments (only available for Beam mesh types)

These loads can be solved at the same time. You also can solve loads one at a time to compare the effect of each on the model. For more information, see Suppress individual loads to compare results.

Defining loads

You define loads by first selecting model geometry, and then specifying a direction to apply the load and a value for the magnitude of the load. When defining some types of loads, such as a pressure load, geometry selection also defines a load direction vector, which you can accept or reverse.

The commands in the following Loads groups on the Simulation tab define a variety of loads based on environment, model type, study type, and mesh type:

  • In the Structural Loads group, you can select Force, Pressure, Hydrostatic Pressure, Torque, Displacement, and Bearing.

  • In the Body Loads group, you can select loads that apply to the entire model at once: Body Temperature, Centrifugal, and Gravity.

  • In the Thermal Loads group, you can select loads used in heat transfer analysis: Heat Generation, Heat Flux, Convection, Radiation, and (gradient) Temperature.

  • In the External Loads group, you can apply the results from a Simcenter FLOEFD for QY CAD analysis file (*.fld) to an assembly model using the Import Fluid Pressure or Import Fluid Temperature commands.

Note:

For Beam mesh types, Force, Moment, and Displacement load types are available.

Selecting geometry

The specific load command you choose determines the type of geometry you can select.

In general, you can select bodies, edges, points, curves, and surfaces to apply the load to. If you are using a tetrahedral or surface mesh type, you also can select face sets and features. The structural nodes or elements that are associated with the selected geometry will have the load applied to them when analysis begins.

You can select geometry from PathFinder or by selecting it in the graphics window.

Note:

  • If possible, avoid applying a load on a point or curve, as it can concentrate stresses.

  • Split surfaces distribute loads and constraints more realistically.

Defining load magnitude

Every load requires a value to specify the magnitude of the load to apply. A dynamic input box is displayed for you to enter this value when you create or modify a load. The default units that are displayed in the box are predefined on the Units tab in the QY CAD Options dialog box, when you select the Advanced Units button.

You also can enter the load value using different units, and the value converts and displays in the default units.

For some load types, such as force, torque, bearing, and moment loads, you can select the Total Load option on the command bar to distribute the load value proportionally based upon the area or length of similar entities.

If the Total Load option is not available, or if you choose not to use it, then the full load value is applied to each entity.

Modifying loads

To modify a load, you first select the load name on the Simulation pane or double-click the load handle in the graphics window.

  • To rename or delete the load, right-click the load name in the Simulation study navigator pane.

  • To modify the load definition, such as to redefine the load value or direction, use the Loads command bar. You can click the load edit definition handle in the graphics window to display the command bar.

You also can double-click a load name in the Simulation pane.

See Modifying and reusing analysis studies.

Suppress, unsuppress, and remove study geometry Define a load

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