 
 
 
 
 
 
 
  
In the case of static calculations with surface-to-surface penalty contact the
displacement increment 
 in each iteration is scaled
with a scalar
 in each iteration is scaled
with a scalar  in order to get better convergence.
 in order to get better convergence.  is
determined such that the residual (i.e. external force minus internal force) of the scaled solution
 is
determined such that the residual (i.e. external force minus internal force) of the scaled solution 
 is orthogonal to the displacement increment:
 is orthogonal to the displacement increment:
|  | (389) | 
Now, the residual for  is known from the previous increment, and
the residual for
 is known from the previous increment, and
the residual for  is known from the present increment. In between a
linear relationship is assumed (cf. Figure 127), which yields the
value of
 is known from the present increment. In between a
linear relationship is assumed (cf. Figure 127), which yields the
value of  without extra calculations. With the
*CONTROLS card the user can specify a value for
 without extra calculations. With the
*CONTROLS card the user can specify a value for
 (default: 0.25) and
 (default: 0.25) and 
 (default: 1.01).
(default: 1.01).