A NEWMAN–PENROSE CALCULATOR FOR INSTANTON METRICS

We present a Maple11+GRTensorII based symbolic calculator for instanton metrics using Newman–Penrose formalism. Gravitational instantons are exact solutions of Einstein's vacuum field equations with Euclidean signature. The Newman–Penrose formalism, which supplies a toolbox for studying the exact solutions of Einstein's field equations, was adopted to the instanton case and our code translates it for the computational use.

A Preprocessor for the Treatment of Elastic Bodies in Multibody Systems

A preprocessor providing the inertia data of elastic bodies for multibody algorithms is considered. The desired capability of including stress stiffening terms leads to a high computational effort. The method presented allows a straight forward implementation of the basic formulas by starting with the development of a special purpose symbolic calculator. A rotating elastic ring serves as an example.