Random vibration analysis design methodology applied on aircraft components - case study on a Lockheed Martin C-130H instrument panel retrofit

Abstract

In the aeronautical industry, qualification and certification processes are very complex not only because safety has to be ensured, but also because there is regulation that must be fulfilled. This dissertation has its origin on the necessity of assisting a design certified company credited as DOA (Design Organization Approval) in a preliminary phase of a modification project, and fulfill the need of developing an analysis methodology at a preliminary design phase that allows to produce confident results in a short time. The modification in study consists in a flight instruments retrofit (upgrade) for Lockheed Martin C-130 H aircraft series. One of the main concerns on the modified instrument panel is its level of vibration. Random vibration is recognized as the most realistic method of simulating the dynamic environment of military applications. PSD (Power Spectral Density) is a statistical measure defined as the limiting mean-square value of a random variable and it is used in random vibration analyses in which the instantaneous magnitudes of the response can be specified only by probability distribution functions that show the probability of the magnitude taking a certain value. The purpose of this work is a creation of an efficient methodology which is intended to provide guidance for future possible projects of modification and fulfills the requirements of MIL-STD- 810G. The design methodology was implemented in a case study: the Lockheed Martin C-130H instrument panel retrofit (upgrade). Case study simulations were carried out through FEM (Finite Element Method).