3.2.5.6. Secant Newton Algorithm

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

Argument	Type	Description
$tangIter	string	tangent to iterate on, options are current, initial, noTangent. default is current.
$tangIncr	string	tangent to increment on, options are current, initial, noTangent. default is current
$maxDim	float	max number of iterations until the tangent is reformed and acceleration restarts (default = 3) of iterations within a time step until a new tangent is formed

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.

Note

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

Note

References:

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