TY - EJOU
AU - Morganti, S.
AU - Fahrendorf, F.
AU - Lorenzis, L. De
AU - Evans, J. A.
AU - Hughes, T. J. R.
TI - Isogeometric Collocation: A Mixed Displacement-Pressure Method for Nearly Incompressible Elasticity
T2 - Computer Modeling in Engineering \& Sciences
PY - 2021
VL - 129
IS - 3
SN - 1526-1506
AB - We investigate primal and mixed u−p isogeometric collocation methods for application to nearly-incompressible
isotropic elasticity. The primal method employs Navier’s equations in terms of the displacement unknowns, and the
mixed method employs both displacement and pressure unknowns. As benchmarks for what might be considered
acceptable accuracy, we employ constant-pressure Abaqus finite elements that are widely used in engineering applications. As a basis of comparisons, we present results for compressible elasticity. All the methods were completely
satisfactory for the compressible case. However, results for low-degree primal methods exhibited displacement
locking and in general deteriorated in the nearly-incompressible case. The results for the mixed methods behaved
very well for two of the problems we studied, achieving levels of accuracy very similar to those for the compressible
case. The third problem, which we consider a “torture test” presented a more complex story for the mixed methods
in the nearly-incompressible case.
KW - Isogeometric analysis; isogeometric collocation; nearly-incompressible elasticity
DO - 10.32604/cmes.2021.016832