Analysis of Isolated Footing using Elastic Foundation (Springs) in Abaqus

  1.  Choose Units, i.e., MKS or FPS. For this problem, we will use N, m and seconds as units.
  2. Make Rectangular footing in Sketch in Parts. Give it thickness as we want to model it as Solid Plate. Take footing dimension as 2x2x0.5
  3. Define Material as Concrete density (23.60) (note: correct this value when you practice it to 23.60e3), Elasticity (20e6) and Poisson’s ratio (0.2).
  4. We need to partition the plate so that we get point for application of load in centre. Tools>Partition in Part Module.
  5. Assign instance in assembly and then define interaction of Elastic Foundation in interaction module. Give value of Spring as 1. Note that the purpose of taking simplified value of load, dimension and spring is to get easy to interpret value of deflection to verify calculations.
  6. Mesh the footing from mesh module.
  7. Define load application step and apply concentrated load of 4 in negative 3-direction.
  8. Create Job and run the analysis.
  9. Open Result and check maximum deflection. As applied pressure is 4/4 = 1 and resisting stiffness per area is also 1 so from F = K*x, the resulting deflection will be 1 units. Again note that such values are pre-decided to have an easy cross-check on calculations.
  10. Check plots and deflection contour. And save the database cae file.

CAE file of abaqus can be downloaded from: CAE file