How to turn friction off for a Concentrated Force?
Friction is defined by resistance that one surface or object encounters when moving over/against another. When adding a concentrated force the force itself is applied to the pipe so there is no friction between the force and the node point it was assigned too. However, if the concentrated force causes a gap to close or applies more load on an already closed gap then, Yes, the concentrated force would be taken into account when calculating the frictional force at the support.
Friction can be controlled by the following settings:
Friction can be applied to the following supports.
The value entered (c) is used to calculate the effect of friction forces generated at the supported point once the bearing spring is in contact with the pipe (where Ffric = c × FBS). A non-zero friction force acts orthogonal to the direction of the bearing spring, and it resists the movement of the pipe.
a. The Non Linear (Gaps/Friction/Soil) option determines the type of analysis to be performed.
A linear analysis ignores all defined support gaps and friction coefficients, and assumes a linear soil stiffness response.
A Non-linear analysis the non-linearities induced by defined support gaps, friction effects at a support bearing spring once a gap closes, and soil yield effects, are all considered.
In addition, a non-linear analysis has the following 3 options available.
b. Ignore Friction E - to ignore friction for all static seismic cases E1, E2 etc defined in the model
c. Ignore friction Gr - to ignore friction for the gravity load case
d. Friction scall factor - Each friction coefficient is multiplied by this scale factor
On the Soil calculator, enter values for Coating Factor and Friction Angle.