Configuration - Boundary Conditions

Boundary Conditions

In the Boundary conditions area, the "Plus" button is used to create the boundary conditions required for optimization. To do this, enter a name and select the concerned space. The load case relevant for the boundary condition (several are also possible) is then activated in the lower list of load cases. The boundary condition can be either a force, a fixation or a moment. Forces, fixations and moments are always specified in component notation in the main coordinate directions

Although the units within a model must be consistent, the choice of the unit system is left to the user (see Settings). The metric system is provided with the units kilogram, millimeter and Newton (kg, mm, N). STL files are often stored in mm and forces are given in N. Accordingly, the unit of the appropriate moment is Nmm

For the different boundary conditions, there are different approaches for the structure and design of the optimization model. In the following, different possibilities for the generation of different boundary conditions are presented and special features of the software are pointed out. A specified boundary condition (force, fixation, moment) always refers to the entire object. To support the input process, an area of a volume can be clicked directly after activating the check box "Force" or "Moment" and thus a direction orthogonal to the surface can be defined. This can be particularly advantageous for round surfaces, hollow cylinders of bolting points or bearing seats. By dragging the mouse pointer, an approximate load size can be defined directly afterwards. The exact values of the spatial directions can then be corrected and adapted via the input fields.

• Loads
  • Forces are specified per object (volume) and distributed evenly over this object.
  • For a surface load, the active surface with thickness 0 must be loaded as a separate object (.STL file).
  • If only a single force is to act as a point load, a separate (very small) volume must be generated for this. Here it should be pointed out that an idealized point load in reality always corresponds more to an area/volume load!
• Fixations
  • Displacements can be locked in the x, y and z directions.
  • The activation of all displacement restrictions corresponds to a fixed fixation.
  • A floating bearing can be created by selecting only one or two displacement restriction(s).
  • For optimization, each direction must be locked (activated) at least once on any object, so that no rigid-body movement can occur. (Exception when using symmetry, see below).
• Moments
  • Moments also affect entire objects and can be defined in x, y and z directions. The right hand rule can be used to imagine the direction of rotation.