Perform Accelerated Life Testing Data Analysis with Stress Profiles/VBA
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Tutorial: Accelerated Life Testing Data Analysis - Stress Profiles
Below is the VBA version of the tutorial.
VBA Sub Main() 'Declare a new stress profile and define its properties. Dim myProfile As New cProfile myProfile.Name = "StressProfile" myProfile.ProfileType = ProfileTypeEnum_Stress myProfile.IsCyclical = False 'Define four segments for the stress profile. Dim segment As ProfileSegment Dim listofsegments(3) As ProfileSegment Set segment = New ProfileSegment segment.SegmentEnd = 200 segment.Value = 124 Set listofsegments(0) = segment Set segment = New ProfileSegment segment.SegmentEnd = 300 segment.Value = 175 Set listofsegments(1) = segment Set segment = New ProfileSegment segment.SegmentEnd = 350 segment.Value = 200 Set listofsegments(2) = segment Set segment = New ProfileSegment segment.SegmentEnd = 375 segment.Value = 250 Set listofsegments(3) = segment 'Add the segments to the stress profile. myProfile.SetSegments listofsegments 'Declare a new ALTADataSet object. Dim ADS As New ALTADataSet 'Assign the stress profile to the data set. Call ADS.AddStressProfile(myProfile) 'The stress profile uses the logarithmic (power LSR) stress transformation 'and has a use stress level = 100. Call ADS.AddStressDefinition("Stress1", ALTASolverLSR_Power, 100) 'Add the failure times to the data set. Call ADS.AddFailure_2(252, 1, myProfile) Call ADS.AddFailure_2(280, 1, myProfile) Call ADS.AddFailure_2(320, 1, myProfile) Call ADS.AddFailure_2(335, 1, myProfile) Call ADS.AddFailure_2(354, 1, myProfile) Call ADS.AddFailure_2(361, 1, myProfile) Call ADS.AddFailure_2(362, 1, myProfile) Call ADS.AddFailure_2(368, 1, myProfile) 'Add the suspensions to the data set. Call ADS.AddSuspension_2(328, 1, myProfile) Call ADS.AddSuspension_2(375, 3, myProfile) 'Use the cumulative damage - Weibull model to analyze the data set. 'Keep all other analysis settings at default. ADS.AnalysisSettings.ModelType = ALTASolverModel_CumDamage ADS.AnalysisSettings.Distribution = ALTASolverDistribution_Weibull 'Analyze the data set. Call ADS.Calculate() 'Calculate the B1 life and display the result. Dim r As Double r = ADS.FittedModel.Time(.99) MsgBox("B1 Life: " & r) End Sub