Efficient design of spacecraft electronics to satisfy launch vibration requirements.
University of Southampton, School of Engineering Sciences,
This work proposes three tools that improve the spacecraft electronic equipment design process, where these tools reduce the chance of the equipment failing the pre-flight qualification vibration test, whilst also being quick and simple to implement. These relatively simple tools consist of: (1) a list of different component types ordered by their ability to withstand vibration, allowing a user to choose more robust packages over weaker ones; (2) simple maps that roughly show the magnitude of the vibration response over the PCB (Printed Circuit Board), allowing the more sensitive components to be placed away from areas of intense vibration; and (3) a process to create more accurate FE models of the PCB if this is required.
Thus, the primary contribution of this work is to prove the viability and accuracy of these three tools, this is achieved as follows: First, some typical pieces of electrical equipment are modelled using FEA and the results compared with experimental data, this gives the expected modelling accuracy under different conditions. Secondly, it is often easier during modelling to ignore the components’ added mass and stiffness effects on the PCB, the error contributed by this assumption is determined much more accurately and for a much larger number of cases than has been achieved previously. Thirdly, manufacturing and assembly variations cause otherwise identical pieces of equipment to behave differently; the extent of this response variation is measured for some typical pieces of equipment. These three sets of experiments combine to provide enough information to allow the creation of vibration response maps, and also how to calculate the accuracy of such maps. Finally, experimental tests must be carried out to create component failure rate data; this works presents an improved set of tests that measure previously unconsidered failure parameters. Additionally, the correlation of component failures to the local PCB curvature is determined for the first time.
Actions (login required)