TAILIEUCHUNG - Assessing Product Reliability_9

Tham khảo tài liệu 'assessing product reliability_9', kỹ thuật - công nghệ, điện - điện tử phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | . Hazard and cum hazard plotting A life test cum hazard plotting example 4. Plot the time of fail vs the cumulative hazard value on special Cum Hazard paper or construct your own paper as covered below for the exponential and the Weibull model . Example Ten units were tested at high stress test for up to 250 hours. Six failures occurred at 37 73 132 195 222 and 248 hours. Four units were taken off test without failing at the following run times 50 100 200 and 250 hours. Cum hazard values were computed in the following table As with probability plotting you can make your own special hazard plotting paper for many models 1 Time of Event 2 1 failure 0 runtime 3 Rank 4 Reverse Rank 5 Haz Val 2 x 1 4 6 Cum Hazard Value 37 1 1 10 1 10 .10 50 0 2 9 73 1 3 8 1 8 .225 100 0 4 7 132 1 5 6 1 6 .391 195 1 6 5 1 5 .591 200 0 7 4 222 1 8 3 1 3 .924 248 1 9 2 1 2 250 0 10 1 Next ignore the rows with no cum hazard value and plot column 1 vs column 6 . Exponential and Weibull Homemade Hazard Paper The cum hazard for the exponential is just H t At which is linear in t with a 0 intercept. So a simple linear graph paper plot of y col 6 vs x col 1 should line up as approximately a straight line going through the origin with slope A if the exponential model is appropriate. The Dataplot commands and graph of this are shown below LET X DATA 37 73 132 195 222 248 LET Y DATA .1 .225 .391 .591 .924 PLOT Y X http div898 handbook apr section2 2 of 4 5 1 2006 10 42 04 AM . Hazard and cum hazard plotting The cum Hazard for the Weibull is H so a plot ofy vs x on log log paper should resemble a straight line with slope if the Weibull model is appropriate. The Dataplot commands and graph of this are shown below XLOG ON YLOG ON PLOT Y X http div898 handbook apr section2 3 of 4 5 1 2006 10 42 04 AM . Hazard and cum hazard plotting E-LŨI Ì X The equation of the least squares line fit through these points can be .

TỪ KHÓA LIÊN QUAN
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.