Step 16 - Add Loads
      In this step we will be adding linear loads to all the purlin elements in the model suing the grpahical interface as follow: 
      
        - Right click on any purlin in the model, and click 'Select All from Group'
        
- Navigate to the 'Loads' sheet in the Input Workbook
        
- Click on the 'Add' dropdown from the contextual ribbon menu, and click 'Line Load'
        
- Select load case 'LL' and specify 'FZ' value = '-0.3'
        
- Click 'Apply'
        
- Press Escape to deselect all elements and to end all Edit commands
        
We added linear loads of 0.3 N/mm or kN/m in the negative Z direction to all the purlins in the model