Simulation Research Of Ultimate Test Conditions In Particle Impact Noise Detection For Sealed Relays

Particle Impact Noise Detection (PIND) is one of the indispensable methods indetecting remainders within sealed relays. The PIND often occurs erroneous judgementsand omissive judgements in productive practice. Manufacturers usually enhance thestrength of test conditions to reduce the misjudgment ratio, however, there is notheoretical guidance to enhance the strength of test conditions and little research onPIND ultimate test conditions. In this paper, the failure mechanism of ultimate testconditions is analyzed to research its mechanics appraised criterion, put forward theanalysis method to research PIND ultimate test conditions of sealed relays formaximizing the detective capability of PIND, there are important theory significanceand practical value for improving the reliability of sealed relays.Firstly, determine the appraised criterion for PIND ultimate test conditions.Combined with the material fatigue damage theory and the strength theory to analysisthe damage mechanism of sealed relays by excessive test conditions, obtain the damagemode of impact and vibration to tested components. Combined with the materialconditional yield strength theory and Miner theory to establish the appraised criterion ofPIND ultimate impact test conditions. Combined with the material fatigue curve toestablish the appraised criterion of PIND ultimate vibration test conditions.Secondly, put forward simulation analysis method for ultimate test conditions ofsealed relays. Take typical structures of sealed relays as examples, establish mechanicalsimulation models by the finite element method, handle the key parts of the modelsbased on the Hertz contact theory, solve the models with convenient and effective finiteelement method, design impact shaking off test to verify the correctness of the finiteelement models and the effectiveness of the analysis method.Thirdly, determine PIND ultimate test conditions of sealed relays. Simulate andanalysis the stress and strain response process of the tested components under differentexternal impact and vibration excitation, comprehensively considerate the the stress andstrain damage of tested components, the detection precision of test systems andcomparison of appraised criterion for ultimate test conditions, research the ultimatestrength of impact and vibration test conditions that sealed relays could bear in thepremise of no damage, determine PIND ultimate impact and vibration test conditions ofsealed relays, verify the correctness and effectiveness of PIND ultimate test conditionsbased on electric experiments.The research methods of this subject can be also used to research PIND testconditions of sealed electronic components and electronic devices, there are important theory significance and practical value for improving the reliability of the sealedelectronic systems.