How to calculate sample stiffness

  • Thread starter Thread starter febbie22
  • Start date Start date
  • Tags Tags
    Stiffness
AI Thread Summary
To calculate the torsional stiffness of a sample, the formula used is 1/samplek = 1/totalk - 1/machinek, with the machine stiffness (k) provided as 42800 NM/radian. The total stiffness is represented by the slope of the line, given as y = 658x. The slope indicates the total stiffness, and it is necessary to find the shear modulus of the material from this value. By applying the provided equation, the sample stiffness can be determined, which will facilitate the calculation of the shear modulus. Understanding these relationships is crucial for accurate stiffness calculations in torsion.
febbie22
Messages
36
Reaction score
0
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 don't get is what am i meant to do with y=658x,

cheers any help would be great
 

Attachments

Engineering news on Phys.org
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.
 
Last edited:

Thread 'Bubble formation in 4 mm gap vessel'

How did you find PF?: Via Google search Hi, I have a vessel I 3D printed to investigate single bubble rise. The vessel has a 4 mm gap separated by acrylic panels. This is essentially my viewing chamber where I can record the bubble motion. The vessel is open to atmosphere. The bubble generation mechanism is composed of a syringe pump and glass capillary tube (Internal Diameter of 0.45 mm). I connect a 1/4” air line hose from the syringe to the capillary The bubble is formed at the tip...
View full post »
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'

Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'

Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
View full post »

Thread 'Find 3D Printer & Software Resources for Prototype Creation'

I'd like to create a thread with links to 3-D Printer resources, including printers and software package suggestions. My motivations are selfish, as I have a 3-D printed project that I'm working on, and I'd like to buy a simple printer and use low cost software to make the first prototype. There are some previous threads about 3-D printing like this: https://www.physicsforums.com/threads/are-3d-printers-easy-to-use-yet.917489/ but none that address the overall topic (unless I've missed...
View full post »

Similar threads

Engineering Total Lateral Stiffness from Stiffness Matrix
Replies
0
Views
1K
Engineering Stiffness of a Concrete Core in a Multi-Storey Building
Replies
2
Views
2K
I Linear Regression, Population, Sample
Replies
4
Views
2K
4DOF Spur Gear System - Eigenvalues not corresponding with the Eqns?
Replies
4
Views
3K
How much force is required to excite a vibrating machine with a load?
Replies
2
Views
2K
Air spring stiffness calculation
Replies
8
Views
19K
Little help to construct the 4 node-quad shell stiffness matrix
Replies
5
Views
5K
Compute damping as a function of frequency
Replies
2
Views
2K
Calculating the dimensions of a lever and a column
Replies
1
Views
3K
I Error bars in Excel (standard deviation, standard error, percentage)
Replies
4
Views
3K

Hot Threads

Recent Insights

Back
Top