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Old Posted Apr 24, 2014, 6:05 AM
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I'll give some theoretical elements to do and check yourself I did calculations .
The model I performs a simple harmonic oscillation along the X axis on which commutes ( ignoring the vertical movement is small) .
This reciprocating motion generated by the circular movement of the end of the piston which is attached the bearing pin is .
The radius of this circle is 0,11 m and this is the amplitude A. Thus my make model path 2A = 0,22 m, i.e. go from
one end point to another in each half turn of fire.

A complete oscillation but means the pin is to make a full turn , ie to return the model to the extreme position from where he started .
So , if we say that it started from the end should be restored at the end . Makes therefore overall route that went 0.22 and 0.22 that turned = 4A = 0,44 m.
So if you stand by the side of the machine and measure routes , each approach to the machine is a complete path and thus a turn. These speed counting , and the corresponding time in sec. The frequency (Hz) is the fraction : n = number of such full path / same time .
The period of oscillation T, ie the time of a full stroke 0,44 m is T = 1 / n sec

In a full turn of fire , we once maximum positive speed in one direction and once the maximum negative in the other .
Us of course we are interested in the absolute values ​​that are the same .
The same happens with the acceleration, but has maximum absolute value when the speed is zero , ie the ends of the paths .

Maximum speed and maximum acceleration calculated from the angular velocity h is : h = 2n / T.
So : maximum speed U : maxy = h * A * h = 0.11 m / sec, maximum acceleration a: maxa = w2 * A * w2 = 0.11 m/sec2.
These maximum sizes made ​​instantaneously.

If we take the average acceleration , either positive or negative, then we think that the speed went from zero to its maximum
at time T / 4. So the average speed is approximately : a = maxy / ( T / 4 ) = 4 * maxy / T = 4 * 0.11 . W2 / T in m/sec2.
This of course is not true , because at the time T / 4 a is greater ( not entangle you with cosines and sines ) .

In both instances, however, to find the acceleration in g, we must divide the accelerations are m/sec2 the Earth accelerating mass is 9,81 m / sec to say that we have achieved so many acceleration g. I think I was detailed .
What we do in practice and what other factors are taken into account , is a challenge . ;
Analytical results of the experiment .
From 2.45 minutes to 2.50 minutes in 5 seconds makes 10 complete turns .
https://www.youtube.com/watch?v=RoM5pEy7n9Q
That is 40 full turns in 20 sec
1 ) So amplitude A = 0,11 m
2 ) Frequency (Hz) is the fraction : n = number of such full path / corresponding time . So 40/20 = 2 Hz
3 ) The fundamental period of the oscillation period T, ie, the time of a full stroke 0,44 m is T = 1 / n sec So 1/2 = 0,5 sec
4) Angular velocity is h : h = 2n / T. So 2x3 , 14/ 0 , 5 = 12.56
5) Max speed U : maxy = h * A * h = 0.11 m / sec So 12,56 x 0,11 = 1,3816 m / sec
6 ) Maximum acceleration a: maxa = w2 * A * w2 = 0.11 m/sec2. So 12,56 X12 , 56ch0 , 11 = 17.352896
7) Acceleration in g 17,352896 / 9,81 = 1,77 g

Excludes the vertical acceleration.
That model is a scale that raises accelerate too much more than 1,77 g but measured differently than that I counted , and out of math that I do not know. (Which relate mass and acceleration and earn some scales ) these types know their test labs .
This acceleration is acceleration took off real natural earthquake , on a small scale model of 1 to 7.14
This told me the professor.
The largest earthquake ever in the world , was 2,99 g
The strongest structures in Greece built to withstand 0,36 g
To My model was tested at 1,77 g and was not hurt , so I do not know when it fails .
In Greece the largest earthquake that was reached in the 1 g acceleration
Correlation with the Mercalli scale
http://en.wikipedia.org/wiki/Peak_ground_acceleration

Instrumental Intensity, Acceleration (g), Velocity (cm / s), Perceived Shaking, Potential Damage
I ........................... <0.0017 ............... <0.1 ... .... Not felt ............. None
II-III .................. 0.0017 - 0.014 .... 0.1 - 1.1 .......... Weak ........ ...... None
IV .................... 0.014 - 0.039 ...... 1.1 - 3.4 ......... Light ....... ....... None
V ..................... 0.039 - 0.092 ........ 3.4 - 8.1 ......... Moderate .... ....... Very light
VI ....................... 0.092 - 0.18 ........ 8.1 - 16 ......... Strong .. ......... Light
VII ....................... 0.18 - 0.34 .......... 16 - 31 ......... Very strong ........ Moderate
VIII ...................... 0.34 - 0.65 ......... 31 - 60 ......... Severe .. ....... Moderate to heavy
IX ........................ 0.65 - 1.24 .......... 60 - 116 ....... Violent. .......... Heavy
X + .......................> 1.24 ...........> 116 ........... .... Extreme ............. Very heavy

Last edited by seismic; Apr 25, 2014 at 5:48 AM.
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