Secant Newton Algorithm
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)|
The default "cut-out" values recommended by Crisfield (R1=3.5, R2=0.3) are used.
Crisfield, M.A. "Non-linear Finite Element Analysis of Solids and Structures", Vol. 1, Wiley, 1991.
Code Developed by: Michael Scott, Oregon State University