Force

The Force/Torque PropertyManager applies forces, moments, or torques with uniform distribution to faces, edges, reference points, vertices and beams in any direction for use in structural studies. The specified force value is applied to each selected vertex, edge, face or beam. When you apply a force to a face or edge, the specified value represents the magnitude only. For example, if you apply a force that is normal to a full cylindrical face, the vector sum of the applied forces is zero.

You can apply nonuniform forces to faces and to shell edges. A nonuniform force is specified by a force value and force distribution. The force value is set equal to the summation of the absolute values of the forces applied to each face. The force distribution is described by the coefficients of a second-order polynomial in terms of x and y axes of the reference coordinate system as described for variable pressure.

Nonuniform torque is not supported in this release.

• Type. Sets the type of force to apply.

• Force .

• Torque .

• . Select the entities to which the force or moment or torque load is to be applied in the graphics area. Valid entities depend on the load type as follows:

• If you choose Force and select Normal, you can select faces and shell edges.

• If you choose Force and select Selected direction, you can select faces, edges, vertices, or reference points for force. The reference points must lie within the model’s boundary.

• If you choose Torque, you can select faces only.

• Selection. Applies to beams.

• Points. Select points defined by inserting reference geometries.

• Joints . Select the beam joints to apply the force/moment load in the graphics area. Available for mixed and beam mesh only.

• Beams . Select the structural members to apply force/moment loads. Available for mixed and beam mesh only.

• Face, Edge, Plane, Axis for Direction . Select an entity to specify the direction of the selected load. Valid entities depend on the load type as follows:

• If you right-click External Loads and select Force, you can select a face, edge, plane or axis for direction.

• If you right-click External Loads and select Torque, you can select a reference axis, an edge, or a cylindrical face.

In an assembly, you can use reference geometry from the assembly or the components (parts and sub-assemblies) of the assembly.

• Units . Sets the units that will be used to enter numerical values of the force/moment/torque. Available units are: SI, English (IPS), and Metric (G).

• Force/Normal Force/Torque. Sets values for the force components, normal force, or torque.

• If you choose Selected direction, your input depends on the selected entity for direction as follows:

• If you select a plane or a face for direction, specify at least one of the following components:

• Along Plane Dir 1 . Sets the value of the force component along Dir 1 of the plane or face.

• Along Plane Dir 2 . Sets the value of the force component along Dir 2 of the plane or face.

• Normal to plane . Sets the value of the force component normal to the plane or face.

• If you select an axis for direction, specify at least one of the following components:

• Radial . Sets the value of the force component in the radial direction.

• Circumferential . Sets the value of the force component in the circumferential direction.

• Axial . Sets the value of the force component along the axis.

• If you select an edge for direction, specify the following component:

• Along Edge . Sets the value of the force along the selected edge. To reverse the direction of the force, enter a negative value.

• If you select Normal, specify the value of the force .

• If you select Torque , specify the value of the torque.

• Per item. Applies the force or torque value per selected entity.

• Total. Divides the force or torque among selected entities. Applies only when selected entities are of the same type.

• Variation with Time. For linear and nonlinear dynamic studies, you can define a time-dependent force.

• Nonuniform Distribution. Sets options for nonuniform force applied to faces or shell edges.

Check the component's box to specify nonuniform distribution.

• Select a Coordinate System . Select a coordinate system to define the nonuniform force.

• Equation Coefficients. Sets the polynomial coefficients which describe the spatial variation of the force in the selected coordinate system. The coefficients should be specified based on the units of x and y as shown in the following table:

• Symbol Settings. Sets the color and size of the force/torque symbols.

• Edit color. Select a color for the force/torque symbols from the color palette.

• Symbol size . Use the spin arrows to change the size of the force/torque symbols.

• Show preview. Turns on/off the display of the force/moment/torque symbols.

NOTES

The nonuniform force distribution is defined by a reference coordinate system and the associated coefficients of a second-order polynomial.

F(X,Y) = A + B*X  +  C*Y + D*X*Y  + E*X^2 +  F*Y^2

Where:

F(X,Y) = relative magnitude of force applied at a point with coordinates x and y in the selected coordinate system

X, Y  = coordinates of the point relative to the selected coordinate system

A, B, C, D, E, and F are polynomial coefficients

* indicates multiplication

The force value you enter in the force field is the value actually applied to the selected entities, if the force doesn't reverse direction on the geometric entity to which it is applied. If the force reverses direction along a geometric entity (face or edge), the applied force value is equal to the summation of the absolute values of the forces applied to all nodes on the face or edge.

Click here for a summary on specifying force and torque.