RESEARCH ON ACCELERATED RELIABILITY TESTING METHODS APPLICABLE TO NONELECTRONIC COMPONENTS OF FLIGHT CONTROL SYSTEMS.

摘要

The study is concerned with the development of techniques for the testing of electromechanical components in time compressed form. The motivating basis for this work is that presently used statistical testing methods require large numbers of samples and long testing periods to compile meaningful MTBF data. The approach employed herein included: System failure mode analysis,Classification and ranking of failure modes in terms of influence and frequency of occurrence,Physics of failure analysis at part and material levels. 'Measured weakening' (pre-cracking) technique was developed and applied to the most predominate failure parts to generate failures in reasonably short test times. In addition,extraneous or unwanted failures were not produced,which is frequently the case when 'over load'testing is employed. An all mechanical position servo unit was selected as a typical energy conversion flight control system component on which tests were conducted to verify the developed techniques for accelerating reliability testing. The tests results indicated that 'measured weakening'of mechanical parts can be employed to reduce the number of samples required and the test time involved to perform reliability testing. (Author)