Use of the Gauss-Ostrogradsky theorem in the mechanics of rigid and flexible bodies and environments

Abstract

New relations for the calculation of static moments and moments of inertia used in the mechanics of rigid bodies are presented in the work. Using the Gauss-Ostrogradsky theorem, it is possible to determine these values not by the integration over a volume, but over the surface of a body. This is especially advantageous in numerical methods. The next part of the work is focused on the Gauss-Ostrogradsky theorem use in the dynamics of fluids, elastic bodies and magnetic fields. Non-stationary terms, such as local acceleration or time change of magnetic induction, are expressed by presented mathematical model so that their effects in the field V can be expressed by their acting equivalent interpreted over the surface S surrounding the surface of the body. Presented article also points to the possibility of using the Gauss-Ostrogradsky theorem in the interaction of bodies with a fluid, such as bodies with cavities filled with a fluid, that can be produced thanks to the use of modern 3D printing technologies. The article brings the presentation of new mathematical models, including their proofs.