Analysis Model Consistency Checker

Select ‘Modify Geometry> Check and Modify Analytical Model> Check Analysis Model Connectivity’. This open the ‘Analysis Model Consistency Checker’ window.

This function is extremely powerful and useful for detecting, and in some cases repairing, modelling inconsistencies. Modelling inconsistencies refer to cases where the analytical model does not connect, however the physical members appear to connect through collision detection that is performed.

The preceding Model Auto Connect section deals with situations where the analytical centre lines do intersect and manages their node point connections.

Modelling inconsistencies may arise in a number of ways, however inaccurate drawing within MasterFrame and models imported from an external source (particularly ones where consideration has not been given to the accuracy required from an analytical model connection point of view) are two of the most common causes.

Typical modelling inconsistencies are

The end of a physical member falls short of the centre line or end point of another member where connection is intended.

Member do intersect on centre lines and connect analytically; however, they produce multiple node points at very small distances from each other.

Members overlap physically and are intended to be connected, however their centre lines do not intersect.

Running the Check

When this function opens it runs a check operation using the current settings. This operation uses collision detection on the physical member 3D shapes to determine cases where there is collision, but no direct or indirect (connection between points by other members) analytical connection. The settings influence this operation as follows.

Clash detection minimum distance (mm) – This input sets a distance limit beyond which checking the collision of physical members is ignored. For example, if you had 1m deep beam and another beam passing perpendicularly under it that was 0.4m away (hence would be colliding), with this value set to 300mm the clash would be ignored and no issue would be reported.

Merge connected nodes tolerance (mm) – Where physical members collide but are only indirectly connected (by other members), and if the distance between the indirectly connected points is less that this tolerance value, then the points are listed as a suggested change set. This can be seen as the desired minimum distance between node points. It is generally advisable to avoid having node points that are “very close” together, in particular where they cause short members. This can lead to ill-conditioning of the stiffness matrix and undesirable modelling behaviour. The “very short” distance will depend on the model and its section sizes. The default in the function is 50mm.

Changes made to these settings are saved in the registry of the PC, and hence will persist between files.

If you change the settings and/or wish to rerun the check, click on the blue ‘Check’ button.

Viewing the Checks Results

The results of the checks are listed as individual change sets in the tree view window. A change set consists of one or ‘move points’ moving to a new common ‘move to’ position. All change sets are highlighted graphically, with the move points drawn in a smaller light grey dot and the ‘move to’ points drawn in larger grey dot.

You can navigate to a change set either by picking on it the frame graphics (tree view will scroll to the change set item and select it), or by selecting the item in the tree view. You can also move to the previous/next item in the list using the  arrow buttons in the tree view header area. Using these buttons also zooms the frame graphics to the selected change set. You can zoom the frame graphics to the selected change set using the  button in the tree view header.

The current change set is then highlighted with the ‘move points’ in blue and ‘move to’ point in red.

The change sets are listed in the tree view in two main categories as follows.

Auto-connected suggested changes

This lists out the change sets that can be automatically resolved by the program.

Each item/change set can be selected to accept that suggested change using the check box on the tree node item or using the  button in the tree view header area. To reject the suggested change set and remove it from the list click on the  button in the tree view header area. To select/deselect all suggested changes click use the  buttons. A selected change set is drawn in a pale blue/violet colour.

To action the selected/checked changes, click on the ‘Connect All Selected Elements’ button at the bottom of the window. This moves the selected change set ‘move points’ to their ‘move to’ point. When complete the program automatically reruns the check. Items that were previously rejected may reappear in the list.

Disconnected colliding elements – Manual Review

This lists potential model connectivity issues for information purposes only. No automatic changes can be made to these items. Issues such as overlapping internally colliding members that are disconnected are listed in this category. Change sets that conflict with those listed in the Auto -connect suggested changes category are listed here.

It is recommended to firstly review/fix the ‘Auto Connect Suggested Changes’ category before examining the item in this category. If any changes to the modes are required to resolve listed potential issues, then the functions in the Modify Geometry menu should be used.