Beam Definitions

An IMPACT definition is a combination of a Revit family (loadable family for beams) and different settings which together enables the IMPACT user to draw elements and at the same time get automation, e.g. automatic lifters.

To access the beam definitions, go to IMPACT - Elements - Beams. On the project level, there is a definition for an inverted-tee beam prepared for this course. Select the definition and press 'Edit'.

Figure 1. Select beam definition.

General

The first tab of the definition contains information about the geometry and a few settings. 

There are three different ways how to configure the cross-section of a beam. 

1. Predefined beam family - If you already have a Revit family that you want to use, this one can be loaded into the definition with 'Load family'. 
   GIF Load family
   Figure 2. Load family.
     
2. Configure dimensions for the cross-section - If you don't have a Revit family, IMPACT can generate it for you. Select the section type (Inverted Tee in the definition 'IT58') and key in the dimensions you prefer. Generate the family by clicking 'Create family'
    
3. 
   Figure 3. Create family.
    
4. Create a family by drawing the cross-section - For user-defined cross-sections, you can draw the shape and dimensions with model lines in a view. These model lines can later be used to create the preferred family.
   
   
   Figure 4. Create a family from model lines.

For each definition, we need to select a material from the list. 

Figure 5. Select material

When we draw the elements, we need to make sure that they can be produced. With the production line configured, IMPACT will give warnings to the user if an element is too long, wide, high, or heavy for production. 

Figure 6. Production line.

Chamfer

Configure chamfers on the edges of your beam by deciding the size and which edges that should have chamfer. 

Figure 7. Chamfer.

Lift and bracing

To get automated lifts and bracings, we need to configure which cast-in materials to use, as well as a set of rules of how and when they should be used.

Figure 8. Lift and bracing tab.

1. There are two methods of lifting a beam:
   1. Single line - standard
   2. Double line - wide beams
      
      Figure 9. Lift method.
       
2. The top left area of the tab contains the ruleset of how and when to insert the different cast-in materials. The first three parameters decide if one, two, or four lifters should be added to the element based on the length of the element. In the case of four lifters, they will be placed in pairs and the parameter 'Spacing 4 lift points' will control the distance between the lifters in the pair. 
   
   Figure 10. Description of lift settings.
   
   With the default lift types, you can configure two or more setups of cast-in materials, and select which setup should be the default one. An example is the lift angle. The lifters in Figure 8 above are configured for a lift angle of 60°. If the same lift should be used with another lift angle, it should be able to handle more or less mass.
   
   Figure 11. The same lifter with two different lift angles.
    
3. We already know that an element can have one, two, or four lifters inserted. Normally, these three differ in lift type and capacity. To solve this, we have three configurations of cast-in materials to be used as lifters. One for each number of lifts used. 
   
   
   Figure 12. Select the number of lifters to configure.
   
   In the configuration of the cast-in materials, the family types are selected and the user decides which lift type (e.g. lift angle) this component should be used for. The max capacity of mass is also added. This information is used in combination with the rules in section 2 above to optimize which and how many lifts are used in each element. 
   
   
   Figure 13. List of cast-in materials.
    
4. In the top right area, the user can decide how the lifts should be rotated and placed in the length and width direction. There are three options:
   1. Fixed distance - placed with a fixed distance from the side of the element.
   2. Part of length/width - placed with a distance depending on the length of the element. 
   3. Center of gravity - placed according to the center of gravity.
   4. 
      Figure 14. Placement of lifts in the x-direction.
      
      The placement in the width direction is only active when the lift method 'Double line' is used. 
      
      Figure 15. Placement of lifts in the y-direction.

Naming

The last tab in the definition contains information about naming conventions and filtering options.

1. Group - a definition can be included in a group which makes it easy to filter out the beams later on e.g. the IMPACT Production applications. An example could be that we have two definitions for an inverted tee beam that is 580mm wide. The difference is the cast-in material used for the lifts. This may not be important for the people in the production, but they just want to know if these two beams are in the group 400-500mm or 500-600mm. To solve this, we can use the group parameter. 
2. Product - another filter parameter.
3. Prefix designation - on the drawings, there is an option to add a so-called designation that contains a prefix and the element thickness in centimeters + element height in centimeters.
   
   Figure 16. Designation of the element.
4. Prefix element mark - the naming of the elements. 
5. Prefix drawing name - sometimes, the naming of the element and drawings are not the same. In those cases, we can use this parameter to control the prefix for drawings. 

Figure 17. Naming tab.

The last information that can be added to the naming tab is the 'Building Information Properties' (BIP). These are used to get better information from combined models.

Figure 18. Building Information Properties (BIP).

We have now looked at how the definition is configured. The next step is to draw some beams ourselves. 

Next: Draw beams