In this study, structural design and analysis of a type-3 composite over wrapped pressure vessel used in a military satellite propulsion system is presented. The aim is to design a composite tank lighter than all metal fuel tanks having the same volume. Moreover, necessary design stages have been revealed for similar composite over wrapped pressure vessels. ANSYS® is used to perform the stress-strain analysis of both metal and composite parts, to determine the optimum winding angle, tank Autofrettage and fracture characteristic for the metal liner considering the crack morphology. Tsai-Hill, Tsai-Wu and Hashin theories have been implemented to investigate the various failure modes of the composite vessel. Location, size and orientation angle of semi-elliptical surface crack has a pronounced effect on fracture characteristic of the liner. In fracture investigation J-integral method is used. It is foreseen that even in the most critical crack, the crack will not propagate and there will be no burst in the tank for proposed loading conditions. Numerical results are good agreement with the experimental results.

This paper describes the comparison of the finite element dynamic analyses and ground vibration test results of the RASAT Structural Qualification Model (SQM), and evaluation of those. Satellite structures and subsystems are exposed to extremely high dynamic conditions during launch. In order to observe the survivability of satellite structure, various methods are evaluated. Main methods are structural finite element analysis and ground vibration testing.RASAT, which is the first micro satellite designed and manufactured in Turkey, has a finite element mesh model. First, modal analysis was run and modal frequencies and mode shapes were evaluated. Then, sinusoidal and random vibration analyses were conducted in order to observe the response of the RASAT structure to these dynamic conditions.RASAT has SQM, on which dummies of main flightidentical structural elements and electronic component and harness are placed. Various ground vibration tests are conducted on RASAT SQM aiming to observe the real satellite modal frequencies and dynamic responses.In order to verify the finite element model and check the structural integrity, the results of vibration tests were compared with the analysis results. As similar to vibration tests, from the analyses run, the responses of the corresponding nodes for accelerometer locations were recorded. In other words, the frequency response functions are determined in X, Y, Z directions after the analyses. Those two results were compared and the differences and deviations were observed. According to these outcomes, some comments on whether the finite element model was sufficiently good or not and the other possible reasons for these differences and deviations were summarized