Tensile Components Example - Revision history

Kate Racaza at 04:00, 15 August 2012

2012-08-15T04:00:47Z

← Older revision		Revision as of 04:00, 15 August 2012
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	However, a more accurate way to obtain the information is to use the Quick Calculation Pad (QCP) in ALTA. Using the QCP, the life for a 10% probability of failure at 50 kips is estimated to be 11,669.1 landings, ~~as shown next~~. ~~Therefore~~, the ~~design criterion~~ of 10,000 landings is met.		However, a more accurate way to obtain the information is to use the Quick Calculation Pad (QCP) in ALTA. Using the QCP, the life for a 10% probability of failure at 50 kips is estimated to be 11,669.1 landings. This is very close to the requirement. In addition, this estimate was obtained at the 50% confidence level. In other words, 50% of the time life will be greater than 11,669.1 landings, and 50% of the time life will be less. Thus, we need to obtain an estimate of the lower confidence level before any decisions are made. The following figure shows the QCP calculation that includes a 90% lower 1-sided confidence bound on the estimate. The lower confidence bound is estimated to be 9,680.84 landings. Thus, the 10,000 landings criterion is not quite met.


	[[Image:ipl_example2_qcp.gif\|center\|500px\|]]		[[Image:ipl_example2_qcp.gif\|center\|500px\|]]

Kate Racaza at 03:54, 15 August 2012

2012-08-15T03:54:14Z

← Older revision		Revision as of 03:54, 15 August 2012
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	A tensile component of a landing gear is put through an accelerated reliability test to determine whether the life goal would be achieved under the designed-in load. Fifteen units, N=15, are tested at three different shock loads. The component is designed for a peak shock load of 50 kips with an estimated return of 10% of the population by 10,000 cycles (or landings). Using the Inverse Power Law-Lognormal model, determine whether the design life is met.		A tensile component of a landing gear is put through an accelerated reliability test to determine whether the life goal would be achieved under the designed-in load. Fifteen units, N=15, are tested at three different shock loads. The component is designed for a peak shock load of 50 kips with an estimated return of 10% of the population by 10,000 cycles (or landings). Using the Inverse Power Law-Lognormal model, determine whether the design life is met.

			The following table shows the data from the test.

	{\|border="1" align="center" style="border-collapse: collapse;" cellpadding="5" cellspacing="5"		{\|border="1" align="center" style="border-collapse: collapse;" cellpadding="5" cellspacing="5"

Kate Racaza at 02:56, 15 August 2012

2012-08-15T02:56:11Z

← Older revision		Revision as of 02:56, 15 August 2012
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	<noinclude>{{Banner ALTA Examples}}</noinclude>		<noinclude>{{Banner ALTA Examples}}</noinclude>
	A tensile component of a landing gear is put through an accelerated reliability test to determine whether the life goal would be achieved under the designed-in load. Fifteen units, N=15, are tested at three different shock loads. The component is designed for a peak shock load of 50 kips with an estimated return of 10% of the population by 10,000 cycles (or landings). Using the Inverse Power Law-~~lognormal~~ model, determine whether the design life is met.		A tensile component of a landing gear is put through an accelerated reliability test to determine whether the life goal would be achieved under the designed-in load. Fifteen units, N=15, are tested at three different shock loads. The component is designed for a peak shock load of 50 kips with an estimated return of 10% of the population by 10,000 cycles (or landings). Using the Inverse Power Law-Lognormal model, determine whether the design life is met.


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	The probability plot can be used to estimate the cycles-to failure for a 10% unreliability probability of failure. According to the plot, the cycles-to-failure is estimated to be <math>T(Q=0.10=10%)\approxeq 12,000</math> landings. (By pressing '''SHIFT''' and clicking the plot, you can display the coordinates and read the value on the X axis that corresponds to a value of 10 in the Y axis.)		The probability plot can be used to estimate the cycles-to failure for a 10% unreliability probability of failure. According to the plot, the cycles-to-failure is estimated to be <math>T(Q=0.10=10%)\approxeq 12,000</math> landings. (By pressing '''SHIFT''' and clicking the plot, you can display the coordinates and read the value on the X axis that corresponds to a value of 10 in the Y axis.)

	Another way to obtain life information is to use the Life vs. Stress plot to plot the life line that corresponds to the 10% unreliability. The following plot shows the 10% unreliability ~~line~~ (the first line from the left). For a stress of 50 ~~psi~~ (X-axis) and for the 10% unreliability line, the cycles-to-failure can be obtained by reading the value on the Y-axis. Again, <math>T(0.1)\approxeq 12,000</math> landings.		Another way to obtain life information is to use the Life vs. Stress plot to plot the life line that corresponds to the 10% unreliability. The following plot shows the life line for the 10% unreliability (the first line from the left). For a stress of 50 kips (X-axis) and for the 10% unreliability line, the cycles-to-failure can be obtained by reading the value on the Y-axis. Again, <math>T(0.1)\approxeq 12,000</math> landings.

Kate Racaza at 02:53, 15 August 2012

2012-08-15T02:53:44Z

← Older revision		Revision as of 02:53, 15 August 2012
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	=~~==Tensile Components Example===~~		<noinclude>{{Banner ALTA Examples}}</noinclude>
			A tensile component of a landing gear is put through an accelerated reliability test to determine whether the life goal would be achieved under the designed-in load. Fifteen units, N=15, are tested at three different shock loads. The component is designed for a peak shock load of 50 kips with an estimated return of 10% of the population by 10,000 cycles (or landings). Using the Inverse Power Law-lognormal model, determine whether the design life is met.

	A tensile component of a landing gear was put through an accelerated reliability test to determine whether the life goal would be achieved under the designed-in load. Fifteen units, N=15, were tested at three different shock loads. The component was designed for a peak shock load of 50 kips with an estimated return of 10% of the population by 10,000 landings. Using the inverse power law lognormal model, determine whether the design life was met.

	{\|border="1" align="center" style="border-collapse: collapse;" cellpadding="5" cellspacing="5"		{\|border="1" align="center" style="border-collapse: collapse;" cellpadding="5" cellspacing="5"
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	\|}		\|}

	~~====Solution====~~

	The data ~~were~~ entered into ALTA, and the following ~~estimates were obtained~~ for ~~the parameters of~~ the IPL-lognormal model:
			The data are entered into the ALTA standard folio, and the following parameters for the IPL-lognormal model are obtained:


	::<math>\begin{align}		::<math>\begin{align}
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	\end{align}</math>		\end{align}</math>

	The probability plot at each test stress level (73 kips, 95 kips and ~~123~~ kips) ~~was then obtained~~, ~~as shown next~~.
			The following probability plot shows the plot at each test stress level (73 kips, 95 kips and 128 kips) and at the use stress level (50 kips). As you can see, there is a good agreement between the data and the fitted model.

	~~[[Image:new_3.gif\|thumb\|center\|550px\|Probability plots at different shock loads.]]~~

	~~In this plot, it can be seen that there is a good agreement between the data and the fitted model~~. ~~The probability~~ plot ~~at a use stress level of 50 kips is shown next.~~		[[Image:new_3.gif\|center\|550px\|Probability plot]]


	~~[[Image:new_4.gif\|thumb\|center\|550px\|~~The probability plot at a ~~use stress level~~ of ~~50 kips~~.]]		The probability plot can be used to estimate the cycles-to failure for a 10% unreliability probability of failure. According to the plot, the cycles-to-failure is estimated to be <math>T(Q=0.10=10%)\approxeq 12,000</math> landings. (By pressing '''SHIFT''' and clicking the plot, you can display the coordinates and read the value on the X axis that corresponds to a value of 10 in the Y axis.)

	~~Using~~ the ~~Use Level Probability~~ plot, the cycles-to ~~failure for a 10% probability of~~ failure can be ~~estimated~~. ~~From the plot~~, ~~this time is estimated to be~~ <math>T(Q=0.~~10=10%~~)\approxeq 12,000</math> landings.		Another way to obtain life information is to use the Life vs. Stress plot to plot the life line that corresponds to the 10% unreliability. The following plot shows the 10% unreliability line (the first line from the left). For a stress of 50 psi (X-axis) and for the 10% unreliability line, the cycles-to-failure can be obtained by reading the value on the Y-axis. Again, <math>T(0.1)\approxeq 12,000</math> landings.
	Another way to obtain life information is by using a Life vs. Stress plot. Once a Life vs. Stress plot is selected, the 10% unreliability (probability of failure) line must be plotted. To do this, click Life Lines... in the plot panel and and select the 10% Unreliability box (or enter 10 in one of the boxes and select the box) in the Specify Life Lines window, as shown next.

	~~[[Image:ipl_example_specify_life.gif\|center\|400px\|]]~~

	~~In the following plot, the 10% unreliability~~ line ~~is plotted~~ (~~the first line from the left). For a stress of 50 psi (X-axis~~) and ~~for the~~ 10% unreliability line~~, the cycles-to-failure can be obtained by reading the value on the Y-axis. Again, <math>T~~(0.~~1)\approxeq 12,000</math> landings~~.		[[Image:new_5.gif\|center\|500px\|Median Life line (right) and 10% unreliability line (left) vs. stress.]]

	~~[[Image:new_5.gif\|thumb\|center\|500px\|Median Life line (right) and 10% unreliability line (left) vs. stress.]]~~

	However, a more accurate way to obtain ~~such~~ information is ~~by using~~ the Quick Calculation Pad (QCP) in ALTA. Using the QCP, the life for a 10% probability of failure at 50 kips is estimated to be 11,669.1 ~~cycles (or~~ landings), as shown next.		However, a more accurate way to obtain the information is to use the Quick Calculation Pad (QCP) in ALTA. Using the QCP, the life for a 10% probability of failure at 50 kips is estimated to be 11,669.1 landings, as shown next. Therefore, the design criterion of 10,000 landings is met.


	[[Image:ipl_example2_qcp.gif\|center\|500px\|]]		[[Image:ipl_example2_qcp.gif\|center\|500px\|]]

	~~The design criterion of 10,000 landings is met.~~

Kate Racaza: moved Template:Tensile Components Example to Tensile Components Example: incorrect namespace

2012-08-15T02:04:51Z

moved Template:Tensile Components Example to Tensile Components Example: incorrect namespace

← Older revision	Revision as of 02:04, 15 August 2012
(No difference)

Richard House at 06:57, 9 August 2012

2012-08-09T06:57:54Z

← Older revision		Revision as of 06:57, 9 August 2012
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	===Tensile Components Example===		===Tensile Components Example===


	A tensile component of a landing gear was put through an accelerated reliability test to determine whether the life goal would be achieved under the designed-in load. Fifteen units, N=15, were tested at three different shock loads. The component was designed for a peak shock load of 50 kips with an estimated return of 10% of the population by 10,000 landings. Using the inverse power law lognormal model, determine whether the design life was met.		A tensile component of a landing gear was put through an accelerated reliability test to determine whether the life goal would be achieved under the designed-in load. Fifteen units, N=15, were tested at three different shock loads. The component was designed for a peak shock load of 50 kips with an estimated return of 10% of the population by 10,000 landings. Using the inverse power law lognormal model, determine whether the design life was met.

	~~<br>~~		{\|border="1" align="center" style="border-collapse: collapse;" cellpadding="5" cellspacing="5"
	{\|~~style=~~ border="1" align="center"
	!Failure, in Cycles		!Failure, in Cycles
	!Shock Load, kips		!Shock Load, kips
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	\|216\|\| 128		\|216\|\| 128
	\|}		\|}
	~~<br>~~
	====Solution====		====Solution====


	The data were entered into ALTA, and the following estimates were obtained for the parameters of the IPL-lognormal model:		The data were entered into ALTA, and the following estimates were obtained for the parameters of the IPL-lognormal model:


	::<math>\begin{align}		::<math>\begin{align}
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	\end{align}</math>		\end{align}</math>


	The probability plot at each test stress level (73 kips, 95 kips and 123 kips) was then obtained, as shown next.		The probability plot at each test stress level (73 kips, 95 kips and 123 kips) was then obtained, as shown next.

	~~<br>~~		[[Image:new_3.gif\|thumb\|center\|550px\|Probability plots at different shock loads.]]
	[[Image:new_3.gif\|thumb\|center\|~~500px~~\|Probability plots at different shock loads.]]
	~~<br>~~

	In this plot, it can be seen that there is a good agreement between the data and the fitted model. The probability plot at a use stress level of 50 kips is shown next.		In this plot, it can be seen that there is a good agreement between the data and the fitted model. The probability plot at a use stress level of 50 kips is shown next.

	~~<br>~~		[[Image:new_4.gif\|thumb\|center\|550px\|The probability plot at a use stress level of 50 kips.]]
	[[Image:new_4.gif\|thumb\|center\|~~500px~~\|The probability plot at a use stress level of 50 kips.]]
	~~<br>~~

	Using the Use Level Probability plot, the cycles-to failure for a 10% probability of failure can be estimated. From the plot, this time is estimated to be <math>T(Q=0.10=10%)\approxeq 12,000</math> landings.		Using the Use Level Probability plot, the cycles-to failure for a 10% probability of failure can be estimated. From the plot, this time is estimated to be <math>T(Q=0.10=10%)\approxeq 12,000</math> landings.
	Another way to obtain life information is by using a Life vs. Stress plot. Once a Life vs. Stress plot is selected, the 10% unreliability (probability of failure) line must be plotted. To do this, click Life Lines... in the plot panel and and select the 10% Unreliability box (or enter 10 in one of the boxes and select the box) in the Specify Life Lines window, as shown next.		Another way to obtain life information is by using a Life vs. Stress plot. Once a Life vs. Stress plot is selected, the 10% unreliability (probability of failure) line must be plotted. To do this, click Life Lines... in the plot panel and and select the 10% Unreliability box (or enter 10 in one of the boxes and select the box) in the Specify Life Lines window, as shown next.

	~~<br>~~		[[Image:ipl_example_specify_life.gif\|center\|400px\|]]
	[[Image:ipl_example_specify_life.gif~~\|thumb~~\|center\|~~500px~~\|]]
	~~<br>~~

	In the following plot, the 10% unreliability line is plotted (the first line from the left). For a stress of 50 psi (X-axis) and for the 10% unreliability line, the cycles-to-failure can be obtained by reading the value on the Y-axis. Again, <math>T(0.1)\approxeq 12,000</math> landings.		In the following plot, the 10% unreliability line is plotted (the first line from the left). For a stress of 50 psi (X-axis) and for the 10% unreliability line, the cycles-to-failure can be obtained by reading the value on the Y-axis. Again, <math>T(0.1)\approxeq 12,000</math> landings.

	~~<br>~~
	[[Image:new_5.gif\|thumb\|center\|500px\|Median Life line (right) and 10% unreliability line (left) vs. stress.]]		[[Image:new_5.gif\|thumb\|center\|500px\|Median Life line (right) and 10% unreliability line (left) vs. stress.]]
	~~<br>~~

	However, a more accurate way to obtain such information is by using the Quick Calculation Pad (QCP) in ALTA. Using the QCP, the life for a 10% probability of failure at 50 kips is estimated to be 11,669.1 cycles (or landings), as shown next.		However, a more accurate way to obtain such information is by using the Quick Calculation Pad (QCP) in ALTA. Using the QCP, the life for a 10% probability of failure at 50 kips is estimated to be 11,669.1 cycles (or landings), as shown next.

	~~<br>~~		[[Image:ipl_example2_qcp.gif\|center\|500px\|]]
	[[Image:ipl_example2_qcp.gif~~\|thumb~~\|center\|500px\|]]
	~~<br>~~
	The design criterion of 10,000 landings is met.		The design criterion of 10,000 landings is met.

Chris Kahn: /* Solution */

2012-06-25T13:19:57Z

Solution

← Older revision		Revision as of 13:19, 25 June 2012
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	<br>		<br>
	[[Image:new_3.gif\|thumb\|center\|~~300px~~\|Probability plots at different shock loads.]]		[[Image:new_3.gif\|thumb\|center\|500px\|Probability plots at different shock loads.]]
	<br>		<br>

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	<br>		<br>
	[[Image:new_4.gif\|thumb\|center\|~~300px~~\|The probability plot at a use stress level of 50 kips.]]		[[Image:new_4.gif\|thumb\|center\|500px\|The probability plot at a use stress level of 50 kips.]]
	<br>		<br>

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	<br>		<br>
	[[Image:ipl_example_specify_life.gif\|thumb\|center\|~~300px~~\|]]		[[Image:ipl_example_specify_life.gif\|thumb\|center\|500px\|]]
	<br>		<br>

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	<br>		<br>
	[[Image:new_5.gif\|thumb\|center\|~~300px~~\|Median Life line (right) and 10% unreliability line (left) vs. stress.]]		[[Image:new_5.gif\|thumb\|center\|500px\|Median Life line (right) and 10% unreliability line (left) vs. stress.]]
	<br>		<br>

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	<br>		<br>
	[[Image:ipl_example2_qcp.gif\|thumb\|center\|~~300px~~\|]]		[[Image:ipl_example2_qcp.gif\|thumb\|center\|500px\|]]
	<br>		<br>
	The design criterion of 10,000 landings is met.		The design criterion of 10,000 landings is met.

Athanasios Gerokostopoulos: Created page with '===Tensile Components Example=== A tensile component of a landing gear was put through an accelerated reliability test to determine whether the life goal would be achieved unde…'

2012-03-21T17:40:21Z

Created page with '===Tensile Components Example=== A tensile component of a landing gear was put through an accelerated reliability test to determine whether the life goal would be achieved unde…'

New page

===Tensile Components Example===

A tensile component of a landing gear was put through an accelerated reliability test to determine whether the life goal would be achieved under the designed-in load. Fifteen units, N=15, were tested at three different shock loads. The component was designed for a peak shock load of 50 kips with an estimated return of 10% of the population by 10,000 landings. Using the inverse power law lognormal model, determine whether the design life was met.

 
{|style= border="1" align="center"
!Failure, in Cycles
!Shock Load, kips
|-
|1855|| 73
|-
|2158|| 73
|-
|2425|| 73
|-
|2736|| 73
|-
|3206|| 73
|-
|614|| 95
|-
|770|| 95
|-
|781|| 95
|-
|890|| 95
|-
|1055|| 95
|-
|152|| 128
|-
|162|| 128
|-
|173|| 128
|-
|209|| 128
|-
|216|| 128
|}
 
====Solution====

The data were entered into ALTA, and the following estimates were obtained for the parameters of the IPL-lognormal model:

::<math>\begin{align}

Std=\ & 0.179080 \\

K=\ & 8.953055E-13 \\

n=\ & 4.638882

\end{align}</math>

The probability plot at each test stress level (73 kips, 95 kips and 123 kips) was then obtained, as shown next.

 
[[Image:new_3.gif|thumb|center|300px|Probability plots at different shock loads.]]
 

In this plot, it can be seen that there is a good agreement between the data and the fitted model. The probability plot at a use stress level of 50 kips is shown next.

 
[[Image:new_4.gif|thumb|center|300px|The probability plot at a use stress level of 50 kips.]]
 

Using the Use Level Probability plot, the cycles-to failure for a 10% probability of failure can be estimated. From the plot, this time is estimated to be <math>T(Q=0.10=10%)\approxeq 12,000</math> landings.
Another way to obtain life information is by using a Life vs. Stress plot. Once a Life vs. Stress plot is selected, the 10% unreliability (probability of failure) line must be plotted. To do this, click Life Lines... in the plot panel and and select the 10% Unreliability box (or enter 10 in one of the boxes and select the box) in the Specify Life Lines window, as shown next.

 
[[Image:ipl_example_specify_life.gif|thumb|center|300px|]]
 

In the following plot, the 10% unreliability line is plotted (the first line from the left). For a stress of 50 psi (X-axis) and for the 10% unreliability line, the cycles-to-failure can be obtained by reading the value on the Y-axis. Again, <math>T(0.1)\approxeq 12,000</math> landings.

 
[[Image:new_5.gif|thumb|center|300px|Median Life line (right) and 10% unreliability line (left) vs. stress.]]
 

However, a more accurate way to obtain such information is by using the Quick Calculation Pad (QCP) in ALTA. Using the QCP, the life for a 10% probability of failure at 50 kips is estimated to be 11,669.1 cycles (or landings), as shown next.

 
[[Image:ipl_example2_qcp.gif|thumb|center|300px|]]
 
The design criterion of 10,000 landings is met.