A numerical method for complex structural dynamics in nuclear plant facilities

The solution of dynamic problems is often connected with difficulties in setting up a system of equations of motion because of the constraint conditions of the system. Such constraint conditions may be of geometric nature as for example gaps or slidelines, they may be compatibility conditions or thermodynamic criteria for the energy balance of a system. The numerical method proposed in this paper for the treatment of a dynamic problem with constraint conditions requires only to set up the equations of motion without considering the constraints. This always leads to a relatively simple formulation. The constraint conditions themselves are included in the integration procedure by a numerical application of Gauss' principle. (orig.)