Load groups are a designated group for particular loadings which are given an identifying name. Each force can be categorised into a group based on its source of origin. For example you could name a load group “Q Live Loads” and included into this group would be all live loads added onto the structure.
The first step to adding and/or assigning a load group is to place a loading onto your structure (this can be done by using the “Loads” section of the main menu within S3D as shown below).
In the process of adding a load onto your structure you are given the options of position, magnitude and also the designation of load group. This is where you can input a name for your load group and consequently assign that load to the given group.
Multiple loadings can be assigned to the same group, to do this you simply use the exact same name (case sensitive) as you used for the previous load assigned to that group. Shown below is the option for naming/assigning a load to a load group:
The names of load groups can be edited at any point via the “Advanced” drop down menu as shown below:
There are 5 main load groups that are generally used within the engineering industry. These groups are as followed:
Also known as self-weight, dead loads are permanent loadings which can cause long term stress on a structure but are generally less prominent in the short term. Self-weight can be applied to the structure in by using the “Self Weight” menu or by clicking the SW indicator in the bottom left hand of the S3D window as shown below:
Also known as imposed actions, live loads are loadings which are generally applied to the structure for short term only rather than long term. These loads include pedestrian traffic, machinery and other imposed loadings.
Wind loads are loadings which are applied onto the structure due to local wind actions. Wind loads are generally broken down into uplift, downforce, suction and drag force.
Snow loads are generally seasonal loadings which can place enormous pressure onto a structure due to the weight of the snow.
Seismic loads are loadings that are generally caused by earth quakes. These loads can cause dynamic effects within structures.
Building codes in each country handles load combinations in slightly different ways. Some building codes will specifiy sub-categories to these main groups. As such, it is recommended to always check with the relevant building code(s) for your needs.