Plotting S-N Diagram with Cycles to Failure

[qwerty0123]

how do i plot the follwing S-N diagram, i am having trouble with what I am supposed to do with the 'cycles to failure' figures:
stress amplitude ... cycles to failure
(y axis)- .... (x axis)
170 ...... 3.7 x 10^4
148 ...... 1 x 10^5
130 ...... 3 x 10^5
114 ...... 1 x 10^6
92 ..... 1 x 10^7
80 ...... 1 x 10^8
74 ...... 1 x 10^9


im confused about what to do with the 3.7 and 3?

 

[SteamKing]

Do you understand scientific notation?

Due to the nature of the data, it is recommended that a log-log plot be used for S-N curves.

 

[qwerty0123]

Do you understand scientific notation?

Due to the nature of the data, it is recommended that a log-log plot be used for S-N curves.

ok...so how would i go about doing that?

 

[qwerty0123]

Do you understand scientific notation?

Due to the nature of the data, it is recommended that a log-log plot be used for S-N curves.

why would you recommend a log-log plot? can i not just plot it as stress against logarithmic scale of the cycles to failure?

 

[SteamKing]

You can. But often if a log-log plot is used, the S-N curve plots as a straight line, which is really handy.

 

[qwerty0123]

You can. But often if a log-log plot is used, the S-N curve plots as a straight line, which is really handy.

well...i've decided to plot stress against the logarithm of the N-values? could you please show me how I am supposed to deal with the figures 3 and 3.7?

 

[SteamKing]

For example, in the table in the OP, a stress amplitude of 170 correlates with 3.7 x 10^4 cycles to failure. 3.7 x 10^4 is scientific notation, and this figure equals 3.7 x 10000 = 37000 cycles. In your plot, assuming you do a log-log plot, the x value of this point is log (37000) = 4.568, and the y value is log (170) = 2.230

I strongly urge you to study and refresh your knowledge of scientific notation.

 

[qwerty0123]

For example, in the table in the OP, a stress amplitude of 170 correlates with 3.7 x 10^4 cycles to failure. 3.7 x 10^4 is scientific notation, and this figure equals 3.7 x 10000 = 37000 cycles. In your plot, assuming you do a log-log plot, the x value of this point is log (37000) = 4.568, and the y value is log (170) = 2.230

I strongly urge you to study and refresh your knowledge of scientific notation.

yeah I am sort of new to this so its taking a while. thanks