Forum: Reliability & Maintainability Questions and Answers
Posted by: Ricardo DiScioscia (email@example.com )
Date posted: Fri Mar 15 14:35:48 US/Eastern 2002
Subject: CL vs ML Environments
I need the specifics to the Cannon Launch & Missile Launch environments listed in PRISM and or 217F. Specifically, I need the shock and random vibration profiles. I would appreciate the help. Thanks.
Posted by: andrew Comons
Date posted: Thu Mar 14 20:25:29 US/Eastern 2002
Subject: Reliability With degraded Mode of Operation
How does the industry handle a MTBF calculation whereby, a mission (single system)may permit operation in a degraded mode? Assuming that a failure did not prevent the degraded mode operation, how would the MTBF calculation be made? For the designer's specification, do I have to specify two different MTBF's - one MTBF for the entire system and another MTBF for degraded system? Or do I specify my maximum mission reliability as the minimum for all hardware relevant to the degraded state? I cannot find much written on this degraded scenario.
Posted by: J Turnbull (firstname.lastname@example.org )
Date posted: Thu Mar 14 10:53:39 US/Eastern 2002
Subject: Electric Permanent Magnet Motor
Does anyone have any experience with reliability predictions for Permanent Magnet Electric Motors?
I am looking for an Overall target for the motor Reliability/failure rate.
Posted by: Johnson Wood (email@example.com )
Date posted: Tue Mar 12 1:54:45 US/Eastern 2002
Subject: Confidence Level of Reliability Calculation
For example, there are tow components in a certain circuit. The failure rate for each of the components are given with a confidence level. One is 40 FITs, the confidence level is 80%, and another one is 15 FITs, the confidence lever is 60%. When I sum the failure rates of these tow components up to calculate the reliability of the circuit, what is the confidence level for the result?
Posted by: ANIL KUMAR (firstname.lastname@example.org )
Organization:CENTRE FOR RELIABILITY
Date posted: Thu Mar 7 6:49:23 US/Eastern 2002
Subject: MECHANICAL RELIABILITY
What is the life characteristic curve and failure distribution for mechanical parts. Electronic parts follow bath-tub characteristic and exponential distribution.What about mechanical components?