User:Kate Racaza/test page: Difference between revisions

From ReliaWiki
Jump to navigation Jump to search
No edit summary
(Replaced content with '=DRAFT=')
 
(15 intermediate revisions by the same user not shown)
Line 1: Line 1:
=DRAFT=
=DRAFT=
{{Template:API}}{{Template:BacktoPrevPage}}
If you have [http://www.reliasoft.com/alta/index.htm ALTA PRO], you can use the Synthesis API to analyze a data set with time-dependent stress profiles. In this tutorial, you will learn how to define stress profiles, analyze a data set, and obtain analysis results from the model.
==Tutorial: Accelerated Life Testing Data Analysis - Stress Profiles ==
The following example demonstrates how to define a single stress profile for an ALTA data set and use the analysis results to obtain the B1 life (i.e., time at which reliability is equal to 99%). A discussion of the example follows.
The data sets used in this example are:
{|{{table}}
|+Stress Profile
|Start||End||Stress
|-
|0||200||125
|-
|200||300||175
|-
|300||350||200
|-
|350||375||250
|}
{|{{table}}
|+Data Set
|Number in State||State||Time to F or S||Number in State||State||Time to F or S
|-
|1||F||252||1||F||354
|-
|1||F||280||1||F||361
|-
|1||F||320||1||F||362
|-
|1||S||328||1||F||368
|-
|1||F||335||3||S||375
|}
'''VB.NET'''
{{APIPrefix|Imports}} SynthesisAPI
{{APIPrefix|Module}} Module1
    {{APIPrefix|Sub}} Main()
  {{APIComment|'Declare a new ALTADataSet object.}}
    {{APIPrefix|Dim}} ADS {{APIPrefix|As New}} ALTADataSet
 
  {{APIComment|'Declare a new stress profile and define its segments.}}
    {{APIPrefix|Dim}} sp {{APIPrefix|As New}} ALTAStressProfile
    sp.AddSegment(200, 125)
    sp.AddSegment(300, 175)
    sp.AddSegment(350, 200)
    sp.AddSegment(375, 250)
    sp.RepeatCycle = False
  {{APIComment|'Use the logarithmic (power LSR) stress transformation.}}
  {{APIComment|'Use stress level = 100.}}
    ADS.AddStressDefinition({{APIString|"Stress1"}}, ALTASolverLSR.Power, 100)
  {{APIComment|'Assign the stress profile to the data set.}}
    ADS.AddStressProfile(sp)
  {{APIComment|'Add the failure times to the data set.}}
    ADS.AddFailure(252, 1, sp)
    ADS.AddFailure(280, 1, sp)
    ADS.AddFailure(320, 1, sp)
    ADS.AddFailure(335, 1, sp)
    ADS.AddFailure(354, 1, sp)
    ADS.AddFailure(361, 1, sp)
    ADS.AddFailure(362, 1, sp)
    ADS.AddFailure(368, 1, sp)
   
  {{APIComment|'Add the suspensions to the data set.}}
    ADS.AddSuspension(328, 1, sp) 
    ADS.AddSuspension(375, 3, sp)
 
  {{APIComment|'Use the cumulative damage - Weibull model to analyze the data set.}}
  {{APIComment|'Keep all other analysis settings at default.}}
    ADS.AnalysisSettings.ModelType = ALTASolverModel.CumDamage
    ADS.AnalysisSettings.Distribution = ALTASolverDistribution.Weibull
 
  {{APIComment|'Analyze the data set.}}
    ADS.Calculate()
  {{APIComment|'Calculate the B1 life and display the result.}}
    {{APIPrefix|Dim}} r {{APIPrefix|As}} Double
    r = ADS.FittedModel.Time(.99)
    MsgBox({{APIString|"B1 Life: "}} & r)
    {{APIPrefix|End Sub}}
{{APIPrefix|End Module}}
==Discussion==
The [[ALTADataSet Class|ALTADataSet]] class represents an ALTA standard folio data sheet. The class contains all the methods and properties that allow you to define a data set and fit a life-stress relationship and distribution to the data.
{{APIComment|'Declare a new ALTADataSet object.}}
  {{APIPrefix|Dim}} ADS {{APIPrefix|As New}} ALTADataSet
Use the [[ALTADataSet.AddStressDefinition|AddStressDefinition]] method to define a stress type and the use stress level.
{{APIComment|'Define a stress type with use stress level = 300.}}
  ADS.AddStressDefinition({{APIString|"Stress1"}},,300)
The data set can contain failures, suspensions or interval data. The following example shows how to use the [[ALTADataSet.AddFailure|AddFailure]] method to define failures and the [[ALTADataSet.AddSuspension|AddSuspension]] method to define suspensions.
{{APIComment|'Add failure times to the data set.}}
  ADS.AddFailure(245, 1, 353)
  ADS.AddFailure(110, 1, 373)
  ADS.AddFailure(180, 1, 373) 
  ADS.AddFailure(200, 1, 373)
  ADS.AddFailure(50, 1, 393)
  ADS.AddFailure(70, 1, 393)
  ADS.AddFailure(88, 1, 393)
  ADS.AddFailure(112, 1, 393)
  ADS.AddFailure(140, 1, 393)
  ADS.AddFailure(160, 1, 393)
   
{{APIComment|'Add suspensions to the data set.}}
  ADS.AddSuspension(250, 5, 353) 
  ADS.AddSuspension(250, 3, 373)
The AnalysisSetting property returns an [[ALTAAnalysisOptions Class|ALTAAnalysisOptions]] object, which represents the analysis settings of the ALTADataSet object. In the following example, we use the <code>ModelType</code> and <code>Distribution</code> properties of the ALTAAnalysisOptions class to specify the life-stress relationship and distribution.
{{APIComment|'Use the Arrhenius-Weibull model to analyze the data set.}}
{{APIComment|'Keep all other analysis settings at default.}}
  ADS.AnalysisSettings.ModelType = ALTASolverModel.Arrhenius
  ADS.AnalysisSettings.Distribution = ALTASolverDistribution.Weibull
To analyze the data set, use the [[ALTADataSet.Calculate|Calculate]] method. The method returns a message box that shows the estimated parameters of the model, based on the settings specified in the AnalysisSettings property.
{{APIComment|'Analyze the data set.}}
  ADS.Calculate()
The FittedModel property gets a [[CModel Class|cModel]] object that represents the fitted model of the accelerated life testing data analysis. From the model, you can calculate useful metrics such as reliability, failure rate, mean time, etc. In this example, we calculate for the B10 life.
{{APIComment|'Calculate the B10 life and display the result.}}
  {{APIPrefix|Dim}} r {{APIPrefix|As}} Double
  r = ADS.FittedModel.Time(.90)
  MsgBox({{APIString|"B10 Life: "}} & r)
==Notes==
For analyses that require a two-stress model, you will need to define two stress types, and then use the overloaded methods to add the data points. For example:
{{APIComment|...}}
{{APIComment|'Define two stress types.}}
  ADS.AddStressDefinition({{APIString|"Temp"}},,328)
  ADS.AddStressDefinition({{APIString|"Voltage"}},,2)
{{APIComment|'Add failure times for Temp &#61; 348 and Voltage &#61; 3.}}
  ADS.AddFailure(620, 1, 348, 3)
  ADS.AddFailure(632, 1, 348, 3)
{{APIComment|...}}
===References===
*[[ALTADataSet Class]]
*[[ALTADataSet.AddStressDefinition|AddStressDefinition Method]]
*[[ALTADataSet.AddFailure|ALTADataSet.AddFailure Method]]
*[[ALTADataSet.AddSuspension| ALTADataSet.AddSuspension Method]]
*[[ALTADataSet.Calculate|ALTADataSet.Calculate Method]]
*[[ALTAAnalysisOptions Class]]
*[[CModel Class|cModel Class]]

Latest revision as of 15:37, 7 September 2016

DRAFT