Continuation methods for tracing the equilibrium path in flexible mechanism analysis

Presents an implementation of continuation methods in the context of a code for flexible multibody systems analysis. These systems are characterized by the simultaneous presence of elastic deformation terms and rigid constraints. In our formulation, the latter terms are introduced by an augmented Lagrangian technique, resulting in the presence of Lagrange multipliers in the set of unknowns, together with displacement and rotation associated terms. Essential aspects for a successful implementation are discussed: e.g. the selection of an appropriate metric for computing the path following constraint, a flexible description of control parameters which accounts for conservative and nonconservative loads, imposed displacements and imposed temperatures (dilatation effects), and the inclusion of second order derivatives of rigid constraints in the Jacobian. A large set of examples is presented, with the objective of evaluating the numerical effectiveness of the implemented schemes.

[1]  E. Riks The Application of Newton's Method to the Problem of Elastic Stability , 1972 .

[2]  H. B. Keller Global Homotopies and Newton Methods , 1978 .

[3]  E. Riks An incremental approach to the solution of snapping and buckling problems , 1979 .

[4]  Werner C. Rheinboldt,et al.  Solution Fields of Nonlinear Equations and Continuation Methods , 1980 .

[5]  M. Crisfield A FAST INCREMENTAL/ITERATIVE SOLUTION PROCEDURE THAT HANDLES "SNAP-THROUGH" , 1981 .

[6]  K. C. Park,et al.  A family of solution algorithms for nonlinear structural analysis based on relaxation equations , 1982 .

[7]  H. Keller The Bordering Algorithm and Path Following Near Singular Points of Higher Nullity , 1983 .

[8]  Isaac Fried,et al.  Orthogonal trajectory accession to the nonlinear equilibrium curve , 1984 .

[9]  Peter Wriggers,et al.  Consistent linearization for path following methods in nonlinear FE analysis , 1986 .

[10]  W. Rheinboldt Numerical analysis of parametrized nonlinear equations , 1986 .

[11]  J. C. Simo,et al.  A three-dimensional finite-strain rod model. Part II: Computational aspects , 1986 .

[12]  A. Chulya,et al.  An improved automatic incremental algorithm for the efficient solution of nonlinear finite element equations , 1987 .

[13]  M. Géradin,et al.  A beam finite element non‐linear theory with finite rotations , 1988 .

[14]  Peter Wriggers,et al.  A general procedure for the direct computation of turning and bifurcation points , 1990 .

[15]  W. L. Rion,et al.  Differential geometry based homotopy continuation , 1990 .

[16]  Alberto Cardona,et al.  Rigid and flexible joint modelling in multibody dynamics using finite elements , 1991 .

[17]  Anders Eriksson,et al.  On improved predictions for structural equilibrium path evaluations , 1993 .

[18]  P. Tallec Numerical methods for nonlinear three-dimensional elasticity , 1994 .