E ect of numerical integrationfor elliptic obstacle problems ?
نویسندگان
چکیده
An elliptic obstacle problem is approximated by piecewise linear-nite elements with numerical integration on the penalty and forcing terms. This leads to diagonal nonlinearities and thereby to a practical scheme. Optimal error estimates in the maximum norm are derived. The proof is based on constructing suitable super and subsolutions that exploit the special structure of the penal-ization, and using quite precise pointwise error estimates for an associated linear elliptic problem with quadrature via the discrete maximum principle.
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