Shell09 – Plate on Elastic Foundation✔
Problem Description
In this example an isolated 50 kip point load is acting on a one inch thick infinitely large plate that is supported on an elastic foundation. For this example the infinitely large plate is modeled as 300 inches long by 300 inches wide and meshed 50x50. The point load is applied at the center of the plate. The plate deflection at the point load location is compared with independent hand calculated results that are computed using theory presented in Timoshenko and Woinowsky-Krieger 1959.
Two different models are created each using a different soil subgrade modulus. Model A uses a subgrade modulus of 30 k/ft3 while Model B uses a subgrade modulus of 800 k/ft3. Those values are chosen to represent approximate upper and lower bound sandy soil stiffnesses.
Tested Features
- Plate bending analysis using shell elements
- Area object spring assignment
- Joint force loads
App
Object 9 Link: https://openbrim.org/objid4dms3g8cdtzsgf1mtdxcy.project
Library
Object 9 Link: https://openbrim.org/objidky4agwirqjrxcnirjq8jr.libobj
Model and Modulus | Output Parameter | OpenBrIM | SAP2000 | Independent | Percent Difference (SAP2000 vs Independent) | Percent Difference (OpenBrIM vs Independent) |
---|---|---|---|---|---|---|
(k = 30 k/ft3) | Uz at center of plate in | -0.9285 | -0.9285 | -0.9205 | 0.9% | 0.9% |
B (k = 800 k/ft3) | -0.1827 | -0.1827 | -0.1782 | 2.5% | 2.5% |