Answer:
If a model has many degrees of freedom or there are several stable or metastable states, the minimal restriction of free translations or rotations of hinges or supports can lead to a faster convergence.
A minimal restriction here means that, for example, a small translational spring of 0.01 kN/m is applied for a nodal support that is freely movable in the global x-direction. The same applies to the rotations. The size of the value strongly depends on the modeled system. Thus, the value of 0.01 kN/m can have too much influence in a very small model.
Image 01 shows the dialog box of a thus limited line support. The translations of the y- and z-directions should be blocked here, but all other degrees of freedom should be free-moving. The small rotation and translation springs thus help in the calculation to achieve faster convergence.
