Developing and assuring the durability of the spacecraft secondary structure

The paper makes a case for the significance and relevance of the subject at hand, states the integrated problem and provides an efficient approach to its solution. The algorithm for developing the secondary structure for a spacecraft is based on many years of experience in practical work on rocket and space technology. The iterative nature of the development process is due to the dependence of the design loads on the resulting parameters of the structure under development. The paper sets forth the principles of designing and developing a finite element model, which is generated concurrently with the design and plays a key role through all the phases of the design effort. To achieve a satisfactory level of fidelity the model needs to be updated based on the results of determination of natural frequencies and gain from developmental tests. Particular features of the models, difficulties in their construction and verification are shown using as specific examples the products developed by RSC Energia. Common principles for constructing models of individual parts of the product, their compatibility, guarantees of their validity and fidelity enable the use of the multi-level model as an efficient tool for providing operational support for the product, in particular, for evaluating the remaining life, analyzing off-nominal situations, upgrading and developing new versions. Consistency in the approach to modeling can be achieved through introduction of appropriate requirements into regulatory documents.