Solver sensor

The  Solver  sensor provides information about the numerical solver in Ashes and can be added from the  Special sensors  button as shown in the figure below

The Solver sensor is meant to help you if you run into non-convergence issues while running nonlinear simulations. Make sure you have a look at the theory manual, in the  Time domain simulation section where the algorithms to solve for the dynamic equations in Ashes are explained.  Concepts like the total Internal energy of the system or the Residual energy for a given time step are relevant for assessing the quality of the results of a nonlinear simulation, but we are still trying to find the best way to make the link between the two in Ashes. If you have any issues, doubts or feedback, please let us know at support@simis.io.

The Solver  sensor provides the following fields:

Field	Unit	Description
Timestep	s	Current time step used by the dynamic solver
Loads with inf magnitude	-	To be removed in the next versions of Ashes
Loads greater than MAXLOADWARNING	-	List of loads whose magnitude is greater than 10 12. This can indicate whether loads have become unphysical, which can be useful in case of non-convergence issue.
Loads, high curvature	-	List of loads for which the second derivative of the magnitude is larger than 10 8 . This can indicate whether loads have become unphysical, which can be useful in case of non-convergence issue.
Iteration count	-	Number of interations necessary to obtain convergence of the Newton-Raphson algorithm in the last time step. If the number of iteration is too large, the simulation will not converge (see Displacement and load residual tolerances were not reached)
Last converged criterion	-	This output takes a value of 1 if the last iteration fulfilled the Relative convergence criteria and 2 if it fulfilled an Absolute criteria (see Time domain simulation).
Total kinetic energy	J	Total kinetic energy in the system, used to evaluate the convergence criteria (see Time domain simulation)
Total strain energy	J	Total strain energy in the system, used to evaluate the convergence criteria (see Time domain simulation)
Kinetic + strain energy	J	The sum of the total kinetic energy and the total strain energy. This is the internal energy of the system.
Total work done by loads	J
Internal energy - external work	J
Accumulated absolute energy residual (transl.)	J	Sum over time of the absolute translational energy residual reported by the dynamic solver, used as a measure of numerical drift
Accumulated absolute energy residual (rot.)	J	Sum over time of the absolute rotational energy residual reported by the dynamic solver, used as a measure of numerical drift