Adjustment Rules

This is a panel of the Structural Analytical Model Generation Rules dialog.

The Goal: A Continuous Structural Analytical Model

In order to perform a structural analysis correctly, the exported model must be continuous: the nodes should be connected. This continuity is required for structural analysis, because a disconnected model results in errors.

The first image below shows the initial Structural Analytical Model: though the physical elements are connected to each other at their core, nevertheless the red (disconnected) nodes of 1D and 2D Members indicate several places where they ought to be connected.

One solution is to create and/or apply Adjustment Rules from the Generation Rules dialog. These rules adjust the specified Member types to each other via Stretch, Cutback, Offset and/or Snap operations.

Important: Adjustments affect the Structural Analytical Model only. They do NOT affect the geometry of Physical Model elements!

As a result, the Structural Analytical Members are automatically connected wherever these rules apply.

https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24-reference-guide/081_structuralanalyticalmodeltools/BeforeGeneration.png 

Before Adjustment Rules: Disconnected Members

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After Adjustment Rules: Connected Members

Conditions for Adjustment

An Adjustment Rule applies to Members only if:

The Members fit the element criteria defined in the Adjustment Rule

The adjustment (e.g. stretching distance) is within the tolerances and conditions set in the Adjustment Rule

The two elements in the adjustment have a core connection (load-bearing cores meet at one or more points or adjoining surfaces) (see also Important Notes, below.)

Adjustments are enabled for this Member in Element Settings.

By default, adjustments are enabled for each Member. However, you can exempt any Member at the element level (to leave the Member unchanged, or to adjust it manually).

See Allow Rule-based modifications - 1D Member or Allow Rule-based modifications - 2D Member.

Important Notes

Certain ARCHICAD functions can help to identify and achieve core connections where they are missing:

See the “Lack of Core Connection” parameter at Physical Model Quality Check

See the Connection Range (Extend Core to Enable Connection) checkbox, in the Element Settings of 1D Members

The current Generation Rules (including Adjustment Rules) go into effect whenever you turn on the Structural Analytical Model - you do not have to activate the rules by command.