Recent content by Jowin86

Does anyone know of any good articles, journals or books that discuss the difference between simplified theoretical analysis of a beam under load and the actual real life effects? Need to do some reading up for an assignment but I'm having trouble finding anything of any merit! Cheers in...

Could you advise me on which equation for MF you would use to plot the theory frequency response for this system given this equation of motion? there's 3 I'm trying to decide between, the bottom is always the same but on top it could be either 1, √1+(2ζr^2) , or r^2 . Following notes i seem...

of course, i see what you're saying now! Thanks!

mx+kx+kYosin(Wt)=-cx is the eom then? It seems to make sense that way. Our lecturer didn't really teach us how to do this, he just did about 2 example and never said how he got the eom. :-/ guess that's uni for you hey. Thank you for your guidance :) Now i just have to sort the two odd...

ignore the previous post I hadn't read your new post. erm, if down is + then i'd say +. so it'd be: mx+kx+kYosinWt=-cx

Yesssssss! am i right about the other side? In which case the eom would be: mx+kx-kYoSinWt=-cx (with the appropriate dots above the x's)

Oh, if y(t) went all over and x stayed still the damper would do nothing.. So on the other side of the = I just have -cx(dot) right?

The graph is both lab data and simulation. The blue line is a plot of the calculated values (using theory) and the 4 symbols are the lab data plotted on there to compare to the calculated values For -k(x-y) then, If the force compresses the spring then it dissipates some energy before...

Ok I'll have another look at that. I put c(x-y) because I had an example like that in the notes for base excitation, but the force was going through the damper on that one so maybe it's not needed for this model? I though pt the -k(x-y) term was ok, guess I'll have to look, P.s. What do...

sorry my e-mail notification only showed me the first line of your reply so didn't see you assigning about the cwy0cos(wt) term... here's my working, i haven't included gravity because like you say it won't affect the data. My thinking with this was, the force is going through the spring...

the mass is dangling against gravity

Hi, I have finally sorted the lower values out! Turns out if i use different method for working them out they come out about right. I have however got two values on the phase lag vs frequency response graph that are odd. Two of the results are close to the theory plot at around r=0.8 to r=0.9...

Oh yeah sorry the frequency of the max MF was 31.17rads Ok I'll send him an email, I should hear back tomorrow he's usually pretty good with replying. I haven't got time to read the wiki article till tomorrow but thank you very much! By the way, is it really ok to discuss coursework on...

Theres nothing attached to the motor to measure displacement, just an accelerometer to measure acceleration. Im not sure if the scope input was ac or dc? Is 'scope input' a setting on the oscilloscope? I will ask my lecturer but I'm not sure what scope input is so not sure what to ask. In...

1) For the theory plot if you take a look at this pdf i found: http://www.colorado.edu/engineering/CAS/courses.d/Structures.d/ASEN3112.Lect21.d/ASEN3112.Lect21.pdf ...on page 21-5, take a look at the equations in the box labeled (21.7). I have used the those to plot the theory by adding...