Author(s)

V. N. Zimin & V. E. Meshkovsky

Abstract

An approximate method for estimating the strength of frame structure elements for the moment of their full deploy is under consideration. Applying this method, it is possible to investigate the mode of deformation for a frame loaded by dynamic forces in the orbit. 1 Introduction In modern space engineering, considerable attention is given to multi-rod deployable frames, consisting of a great number of light elastic tubes connected to each other with spring hinges. Designed for space, such structures have to possess a minimal mass and take a minimal volume in the transport state, under a carrier rocket fairing. Being deployed in the orbit, they have to increase their overall dimensions up to dozens of meters and keep shape accuracy in unfolded operating state. One of the deployable space frames is shown in Fig. 1. Deployment of such structures in the orbit is executed automatically when a restraining element is eliminated, due to previously accumulated energy of springs placed in hinged joints. In the orbit, when a structure is deployed to the operating shape, impact dynamic loads arise and affect on the structure components. Unfolding frame element strength analysis is based on the solution of a problem of the frame deploy and determination of the structure component velocities in the moment when the structure is fully unfolded. So, analysis of a tube element strength during the frame deploy consists of two steps. Firstly, it is necessary to calculate the structure deploy on the assumption that all its elements are perfectly rigid bodies. So we can determine a field of velocities for the elements in the moment when they get fixed in the stops (that is the moment of full deploy). During the second step, it is necessary to investigate the history of

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