Merge the nodes of two touching structural elements
The merge option fuses all nodes that lie within a small circle (or sphere) of area (or space), renumbers nodes in sequence, and then removes any gaps in the numbering system. User can select which structural elements are to be merged together or can request that all structural elements be merged togethe. You must give the merge tolerance, or raidus of this circle (or sphere), which all nodes within this area will be merged.
For example, suppose that two separate but coincident nodes need to be fused. When these nodes are merged, the higher numbered node is deleted and will be replaced with the lower numbered coincident node. These two nodes are thus be replaced by a single node.
Setting merge tolerance to an optimal value is important. If it is set too small nodes may not be merged and it set too large undesired nodes will be merged causing distortion to attached elements.
Merge tool may resolve the Exit 2004 error message when solving. This typically means convergence can not happen due to rigid body motions.
If a merge nodes is required to be executed, the user should know that three options are available for it.
2 Struct. elem. option makes possible that the nearest nodes of two selected structural elements keep together. A tolerance must be defined so as to specify the limiting distance.
All nodes selection execute a merge nodes in the whole structure showed in the model view. That is, merge node will be only available for structural elements which are visible in the model view.
Nodes group option allows to effectuate a merge nodes only in those nodes which have been directly selected by the user.
Add the deformed shape of a results file to the mesh
This tool updates the geometry of the finite element model according to the computed displacement results of the previous analysis and creates a revised geometry with the deformed configuration.
If this command is issued repeatedly, it creates a revised geometry of the finite element model in a cumulative process, i.e., it adds displacement results on the previously generated deformed geometry. Note that the geometry (points, lines, surfaces, volumes) is not updated. This tool affects on all nodes.
A solved results file (.rcf) must exist from a previously homogeneous model. Then its deformed shape shall be scaled:
Scale by max, displacement.
Scale by factor.
This utility is helpful in a nonlinear collapse analysis where imperfections must be performed on a structure. Since a perfect model will not show signs of buckling, imperfections may be added by using eigenvectors that result from an eigenvalue buckling analysis. The eigenvector determined is the closest estimate of the actual mode of buckling. Imperfections added should be small when compared to a typical thickness of the beam is being analyzed.
CivilFEM allows to change nodes or elements number. This is not only available to be executed in a global context, that is, to the whole amount of nodes, but also in groups.
