How is strain different from displacement?

- July 31, 2020 at 4:03 pm
  
  Akismet
  Subscriber
  
  How is strain different from displacement?
- July 31, 2020 at 4:03 pm
  
  Karthik Remella
  Administrator
  
  Hello @bsista . A strain is a measure of how large the deformation is compared to the original shape. On the other hand, displacement is simply a measure of how much different points on a body have moved (with no comparison to its original shape or size). For a one-dimensional and small deformation case, a strain is (L - L0)/L0, where L is the deformed length and L0 is the original length. For large deformation and higher order case, the measurement of strain becomes complicated.
- July 31, 2020 at 4:04 pm
  
  Dragana Jandric
  Forum Moderator
  
  Hi! To add to the above answer, the strains filter out the rigid body modes from displacement. E.g. if all points in the body move 3m in the same direction, the displacement of all the points is 3 m, but the strain at all points is 0 because the shape or size of the body does not change (it simply translates to another location).
  Hope this is helpful!