Preparations

In order to generate an automatic snow load with FEM-Design, we need to define the different roof types (flat roof, lean-to and ridged roof) and the associated structural elements to be taken into account for the snow load. The latter will give the roofs’ so-called “edge objects” that affect snow load intensity. The roof type definition should be done with the Climate load panel command.

Edge objects

Start Snow load macro, and define edge objects manually or automatically. Following edge objects can be defined:

• connected roofs which models multi-span roofs, 
• attic walls, 
• tall building (parts), 
• snow fences, 
• snow overhangs. 

Note:

Edge objects can be assigned only to straight edges. 

Note: 

• If two edge objects next to each other have exactly the same attributes, they are merged automatically. 
• Edge objects cannot be deleted, instead they must set to be None. 

Manual edge object creation

In Snow load dialog, select Define edge object and Draw edge object, then start Default settings and select the edge object type at Snow load panel edge object dialog. Afterwards, select the the corresponding edge of a climate load panel, and finally define the segment (whole or pieces of edge). 

Automatic edge object creation

In Snow load dialog, select Generate edge object(s) automatically and check (or modify) the settings in the Sow load panel edge objects wizard dialog.

FEM-Design algorithm, by investigating the climate load panel items and their connections, can automatically recognize the following types of edge objects

• multi-span roofs, 
• attic walls, 
• tall building parts next to a roof, and 
• bottom, horizontal roof edges to generate snow fences or snow overhangs, if we request for them. 

Note: 

• Edge objects are mutually exclusive to each other. 
• By making splits in a roof region (that was drawn, not associated to a structural element), obstacles (practically attic walls) can be placed inside the roof, too. 
• Obstacles can be only at the edge of the roofs. 

The properties of the defined edge objects can be modified with the Edge object properties tool: 

Note: 

• If two edge objects next to each other have exactly the same attributes, they are merged automatically. 
• Edge objects cannot be deleted, instead they must set to be None.