Secant Newton Algorithm

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This command is used to construct a SecantNewton algorithm object which uses the two-term update to accelerate the convergence of the modified newton method. The command is of the following form:

algorithm SecantNewton <-iterate $tangIter> <-increment $tangIncr> <-maxDim $maxDim>


$tangIter tangent to iterate on, options are current, initial, noTangent. default is current.
$tangIncr tangent to increment on, options are current, initial, noTangent. default is current
$maxDim max number of iterations until the tangent is reformed and acceleration restarts (default = 3)



NOTES:

The default "cut-out" values recommended by Crisfield (R1=3.5, R2=0.3) are used.


REFERENCES:

Crisfield, M.A. "Non-linear Finite Element Analysis of Solids and Structures", Vol. 1, Wiley, 1991.


Code Developed by: Michael Scott, Oregon State University