Experimental Dynamic Load Simulation by Means of Modal Force Vectors WP1-Report.

Abstract

Increase of size and recent advances in lightweight design of space systems require new approaches to structural testing techniques. This report gives a brief survey on different qualification methods. Then a new concept is proposed in which the base excitation of a spacecraft due to the load events, particularly of the launch and/ or reentry phase, can be simulated by a set of forces acting directly in a specially selected number of structural points. The simulating force time histories are calculated by means of modal force vectors. They compensate for the d`Alembert`s inertia forces due to the transient multi-axial base acceleration. Thus, the approach is called the modal force combination (MFC) method. In this study, four versions of the MFC concept are compared, which differ in the modal force vectors used. In conclusion, the specifications for the experimental verification of the MFC concept are given.