Qualification Testing Phase of Satellite Structure - Finite Element Analysis for Satellite Structures - page 249

engineering model of the satellite to check the function of the electrical interfaces
of the pyrotechnic pin-pullers, intended for locking of solar arrays, to check of
electrical interfaces of electrical equipments after releasing the solar arrays once
in-orbit, and modification of design documentation of the electrical tests.
The development of the satellite structure necessitates a good understanding of
the static and dynamic characteristics of the satellite to establish design and test
loads also considering coupled loads dynamic analysis with the launcher [ 1 ]. Static
strength verification is accomplished by a static-centrifugal test. Static tests
objective is the verification of strength of the satellite structure in accordance with
accepted types of loading and determination of load-carrying ability of the
structure. Dynamic tests objectives are determination of the vibration transfer
coefficients to the mounting seats of the satellite's components, modal frequencies
of the satellite structure components and satellite structure as a whole, effect of the
impact loads on satellite's equipments mounting accuracy, and verify the electrical
equipments function due to vibrations.
The focus of this topic is the application of finite element in design, testing, and
manufacturing of satellite structures. It is meant to help mechanical designers and
stress analysts and not test engineers. The topic of vibration testing of spacecraft
structures cannot be discussed in one chapter, and there are many references that
discuss this topic in more details. So, only a survey of the qualification tests are
discussed without going in details that are important for test engineers. Then, finite
element method is used to investigate cracks that were initiated during air trans-
portation vibration test.
6.1 Static Test Specification
The static test objective is to verify the strength of satellite structure under the
loads that act on the satellite flight model during operation [ 2 ]. These loads are
applied on the satellite strength mockup by inertial forces created by the centrif-
ugal stand. Technological brackets are designed and used to fix the satellite
strength mockup on the centrifugal stand. The following tasks have to be achieved,
• The strength of satellite's structural components during its transportation by
automobile, railway, and air transport and during orbital injection;
• Verify the mounting accuracy of the instruments' seats that require precise
referencing to the satellite's coordinate axes after loading conditions;
• Verify the function of solar array locking elements and deployment mechanisms.