Types of Pilot Reinforcement (PR) in LIRA-CAD module: pattern of reinforcement in a column in two layers

Suppose we have to make the automatically generated PR types come from the LIRA-CAD module to the LIRA-FEM program; in these PR types, the reinforcement pattern is arranged in two layers, as shown in Fig. 1.

To solve this problem, let's use the settings for the default rules of PR types assigned in the LIRA-CAD module (Fig. 2).

In our example, two columns with tags C1 and C2 should receive double layer reinforcement. For this purpose, we will create two (according to the number of tags) pairs (according to the number of layers) of rules for PR types.

For column C1, the first rule determines the number and diameter of reinforcement bars in the first layer (closer to the formwork). This rule works as a basic rule. No geometric properties are specified for this rule.

The second rule describes the reinforcement pattern in the second layer. For this rule, to be applied along with the first one, we define a "geometric property" from the beginning to the end of the bar. We declare this property to be "Additional". This means that it does not replace the bars arranged according to the general rule, but introduces additional ones.

As a result, columns C1 and C2 received two PR types each, which can be observed in LIRA-FEM program (see Fig. 3).

Note 1. Do not define both rules in a pair as additional (with geometric properties), because in this case the program will try to add them to the main rule.

Note 2. Do not define to one column both rules with geometric properties that do NOT have the "additional" tag. In this case the program will ignore the number of rules and assign one rule for the whole area of geometric property; this rule will replace the others.

If everything is done correctly, then in LIRA-FEM program in the "PR types" dialog box, you can get the picture shown in Fig.4 - reinforcement bars arranged in two layers.