# Load Types

**LOAD TYPES **In Strut3D user has an option to choose the Load Type applied (

*Characteristic, Design*). By default, application uses

*Characteristic Load Type*option. To change the option, choose

**Analyze -> Calculation Parameters**[Fig. 1 and Fig. 2].

Choice between *Characteristic *and *Design *Load Types entails certain consequences.

*Fig. 1 – Calculation parameters. *

*Characteristic Load Type active.*

Fig. 2 – Calculation parameters.

Design Load Type active.

**CHARACTERISTIC LOAD**

When user decides to apply *Characteristic *forces, then should use correct safety factors for the *Permanent Loads (**Dead*) and *Variable* (*Live*) in *the Calculation Parameters *window (Fig. 1). By default, application uses factors following „Eurocode 0”, what means 1,35 for *Permanent Loads* (*Dead*) and 1,50 for *Variable* (*Live*) Loads. At the ultimate limit state design safety factors are equal to 1,00 for each type of the load.

While defining the *Characteristic* load, user chooses the *Nature of the load (Live/Dead)* [Figure 3], then application automatically associate relevant safety factor.

*Figure 3 – Point load definition dialog. *

*Nature of the load chosen from the list.*

Load combinations are defined per the following rules:

Ultimate limit state:

Serviceability limit state:

Where:

– permanent action (including dead load)

– variable/live action

**DESIGN LOAD**

When user decides to apply load as a *Design*, then there is no possibility to enter safety factors in the *Calculation **Parameters *window [Figure 2]. Additionally, while applying the load there is no possibility to choose the *Load Nature* [Figure 4].

*Figure 4 – Definition of the point load. Design load nature.*

In this case load combinations are defined per the following rules:

Ultimate limit state:

Serviceability limit state:

Gdzie:

– own weight

– applied load (design)

The safety factor 0,74 for the applied loads at the serviceability limit state was evaluated from the relationship: . All applied loads are set into one group. To calculate deflection, the safer solution is to apply reduction factor to the applied design loads dividing them by the dead load safety factor.