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This command is used to construct a LagrangeConstraintHandler which will cause the constraints to be enforced using the method of Lagrange multipliers.
constraints Lagrange <$alphaSP> <$alphaMP>
$alphaSP |
factor used when adding the single-point constraint into the system of equations (optional, default=1.0) |
$alphaMP |
factor used when adding the multi-point constraint into the system of equations (optional, default=1.0) |
NOTE: Values for $alphaSP and $alphaMP other than 1.0 are permitted to offset numerical roundoff problems.
NOTE: The system of equations is not positive definite due to the introduction of zeroes on the diagonal by the constraint equations:
From Cook: "Lagrange's method of undetermined multipliers is used to find the maximum or minimum of a function whose variables are not independent but have some prescribed relation. In structural mechanics the function is the potential energy and the variables are the DOF".
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