
#1
Nov1310, 12:48 PM

P: 38

hi i need to calculate the torsional stiffness of a sample, the data is in the excel file.
To work it out it = 1/samplek= 1/totalk  1/machinek the machine k was given as 42800NM/radian the total k is the slope of the line which comes to y=658x what i dont get is what am i meant to do with y=658x, cheers any help would be great 



#2
Nov1310, 03:28 PM

P: 261

I've done a question very similar to that, and if I remember correctly then the gradient was either one of the stiffnesses or the shear modulus. But it was a year ago and I've not done anything like that since so I'm a little rusty on torsion.
Edit: it's come back to me slightly. You have to find the shear modulus of the material, right? The slope is the total stiffness. Use the given equation to find out the sample stiffness and then you can easily calculate the shear modulus. 


Register to reply 
Related Discussions  
what is the spring stiffness?!??!  Introductory Physics Homework  3  
How to calculate the stiffness of an arch?  Mechanical Engineering  6  
Stiffness of beam  Aerospace Engineering  1  
Sample mean and sample variance  Calculus & Beyond Homework  1  
statistics: sample median, means, s.d. vs sample size  Precalculus Mathematics Homework  2 