Minimum Unbalanced Displacement Norm

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This command is used to construct a StaticIntegrator object of type MinUnbalDispNorm.

integrator MinUnbalDispNorm $dlambda11 <$Jd $minLambda $maxLambda>

$dlambda11 first load increment (pseudo-time step) at the first iteration in the next invocation of the analysis command.
$Jd factor relating first load increment at subsequent time steps (optional, default: 1.0)
$minLambda, $maxLambda arguments used to bound the load increment (optional, default: $dLambda11 for both)


EXAMPLE:


integrator MinUnbalDispNorm 0.1;



THEORY:

The load increment at iteration i, dLambda1(i), is related to the load increment at (i-1), dLambda1(i-1), and the number of iterations at (i-1), J(i-1), by the following:

<math>d\lambda_{1,i} = d\lambda_{1,i-1}*Jd/J(i-1)</math>

In Load Control the time in the domain is set to <math>t + \lambda_{t+1}</math> where,

<math> \lambda_{t+1} = \max \left ( \lambda_{min}, \min \left ( \lambda_{max}, \frac{\text{numIter}}{\text{lastNumIter}} \lambda_{t} \right ) \right ) </math>



Code Developed by: fmk