Document/Example for the use of the convergence parameter "configurationTolerance"

[sytuannguyen]

What needs to be documented?
The parameter configurationTolerance in the solver SolidMechanicsLagrangeContact defines the acceptable converged ratio between the contact area change and the total contact area as shown below:

// Assume converged if changed area is below certain fraction of total area
  return changedArea <= m_nonlinearSolverParameters.m_configurationTolerance * totalArea;

First, the default value of parameter is actually set to 0, which makes the simulation always fail to converge in some senarios (for example a cased wellbore with initial stress condition).

Second, no document or xml example is available to show the importance of this parameter for the simulation convergence.

What sort of documentation would help?

• XML example using configurationTolerance.
• Change the default value to a more reasonable value, or simply change it to 1.0

What are the deficiencies of the existing documentation?

Additional notes or context

[paveltomin]

configurationTolerance was introduced not long time ago as an experimental option
default value of 0.0 preserves old behavior when no configuration change is allowed when convergence is declared
setting it to 1.0 would not make much sense because then configuration will be always assumed converged