Forum: Reliability & Maintainability Questions and Answers
Posted by: Grib khider (email@example.com )
Organization:Aérazur - Zodiac group
Date posted: Mon Nov 8 7:10:55 US/Eastern 2004
Subject: Accelerated testing
We have performed an accelerated test using Arrhenius acceleration factor in order to obtain a service life of fuel tank (acceleration factor between life t at temperature T and life t’ at reference temperature T’).
For the test we have filled a tank with air instead of fuel. I am looking for a factor between air and fuel to apply in order to be more representative of tank utilization. I will really appreciate if someone have a method to obtain this factor or how we can do to be more realistic?
Posted by: vallon (firstname.lastname@example.org )
Date posted: Wed Nov 3 10:34:34 US/Eastern 2004
Subject: power semiconductor reliability data
I search some reliability data about power semiconductor like power MOSFET (75V, 100A) or IGBT (600V, 100A). this kind of device are used in power inverter (DC-AC converter, 40KW) with or without power cycling.
Posted by: Troy
Date posted: Thu Oct 28 15:28:25 US/Eastern 2004
Subject: Attribute Testing
I desire to use attribute testing to determine reliability at a given confidence level. Where can I get information regarding formulas used do derive reliability?
Posted by: PeteD (Pete.Daly@raymarine.com )
Date posted: Thu Oct 28 11:37:34 US/Eastern 2004
Subject: Component stress analysis
I would like to know if anyone is using any software packages that will input a netlist/bom from and electronic CAD ( Such as CADSTAR ), and perform a stress analysis on an actual circuit , calculating ratios like actual resistor power , capacitor voltage etc.
Posted by: Tim Daniels (Tim.Daniels@Fernau.Com )
Date posted: Tue Oct 26 10:09:55 US/Eastern 2004
Subject: Spares level over set period of time
Sorry this may be a silly question but it's the first time I've done anything like this.
I need to calculate the number of spare LRUs required for a product to have 95% confidence level (of having a spare available) when the repair time is 10 months. I have failures/million hours figures and thought the RAC Poisson calculator for sparing was the answer! But now I have to consider a mission time of 18 months and calculate spares for this time only. I cannot see what will change. Can anybody give me any clues? Any ideas will be very much appreciated. Tim