By construction data implies how the construction is built up, which forces are on the bars and junction points, which junction points are wedged in etc.
The entered data is divided into:
• Geometry
• Loads and supports
Geometry
The geometry is determined by the position of the nodal points, the profiles to be used, the bars and how these are connected to 2 nodal points. In such cases the bars can be either hinged or set directly onto the nodal points.
The order of entering data is:
1. Junction points
2. Profiles
3. Rod
4. Loads
5. Supports.
In summary:
A construction exists of rods, interconnected by junction points. Each rod represents a profile. On the rod forces and/or (un)equal loads may be exerted. To the nodal points forces and/or moments may be applied. At the same time a junction point may also be defined as a support.
Rods may be connected to each other directly or hinged.
Entering of Junction points
A nodal point is a point to which one or more bars are attached. You may not create nodal points without connecting bars. The position of the nodal points are determined through the use of X and Y coordinates.
The diagram below represents a lifting mechanism, which we shall use as a guide in this chapter. The construction consists of UNP profiles of which some are hinged to one another.
The lifting is done by a hydraulic cylinder.
