Point Load, Free

Add a node to describe concentrated loads with locations specified by coordinates. Such loads do not have to be placed in a geometrical point or in a mesh node. This is particularly useful for the following cases:

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Imported meshes, where there may not be suitable points for load application

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Moving loads

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Several point loads, in which case it may be impractical to create points at all load locations

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For each free point load, there will be a search for the mesh element that is closest to the given location. For the load to be active, the location must be within a certain small distance from at least one element. The actual load location is taken as the point on the element that is closest to the given location. If no element is found, the load is silently ignored.

You can check the number of loads that were ignored through the variable <phys>.<load_tag>.num_ignored, for example shell.plf1.num_ignored.

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The local stress field in the element where a point load acts will not be reliable.

Location and Force

Select a — , , or . The default is that the load is applied at the midsurface. The effect of using another surface than the midsurface is that for a tangential load, the distance from the midsurface is used to compute an additional equivalent moment load.

To place the load at another distance from the midsurface, select the check box, and enter a value for the offset, zoffset.


	The coordinates that you enter for the load location are not affected by this setting; they should always refer to the reference surface, that is the coordinates of the mesh.

If the material model is , there may physically not be a well-defined top and bottom surface. If the load is applied at such a surface, the thickness value used to compute the load is taken from the settings in the node.

Select a — or that determines how the given coordinates are interpreted in case of a geometrically nonlinear analysis. When is selected, the load location on the body is interpreted with respect to the initial configuration. When is selected, then the load location is given in space fixed coordinates, which usually means that the material point on the body where the load is applied will change with deformation even if the coordinate values are constant.

For each row in the table, enter the data for one load. If material frame input is used, then the location is specified in terms of the material coordinates (, , ). If spatial frame input is used, then the spatial coordinates (, , ) are used. Then, enter the force and moment values, , , , , and . The force and moment vectors are interpreted in the coordinate system selected in the section.

Linear Buckling

To display this section, click the button (

) and select in the dialog box.

If you are performing a linear buckling analysis with a combination of live and dead loads, select the check box to indicate that the load contributions from this node are constant. The default is that a load is proportional to the load factor.


	For more information about live and dead loads, see Buckling Analysis.

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You can specify this load to be a Harmonic Perturbation in a frequency domain analysis.

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You can assign this load to a load group. See Load Cases in the Structural Mechanics Modeling chapter.


	Pratt Truss Bridge: Application Library path Structural_Mechanics_Module/Beams_and_Shells/pratt_truss_bridge

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