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Due to symmetry of the structure and loading, a quarter of the cylindrical shell (as shown above) is used as a model. It consists of 6 x 6 mesh of shell elements.
The edge from joint 1 to 7 is simply supported and from 7 to 49 is free.
The boundary conditions along the edges from joint 1 to 43 and 43 to 49 are prescribed for symmetry. Here are the joint restraints specified for preserving symmetry:
The input for the model should be generated using a cylindrical coordinate system.
Reference
- MacNeal, R.H. and Harder, R.C., "A Proposed Standard Set of Problems to Test Finite Element Accuracy," Finite Elements in Analysis and Design 1 (1985), pp.3-20, North-Holland.
- Zienkiewicz, O. C., "The Finite Element Method," McGraw-Hill, 1977.
Result Comparison
| Axial Z-Displacement in feet at the Support Joints 1-7 | SAP90 | Theory | LARSA | OPENBRIM | PERCENT DIFFERENCE (LARSA vs. THEORY) | PERCENT DIFFERENCE (OPENBRIM vs. THEORY) |
|---|---|---|---|---|---|---|
Location=0.00(deg) | 0.0000 | 0.0004 | 0.0000 | 0.0000 | - | - |
Location=6.67(deg) | 0.0005 | 0.0009 | 0.0005 | 0.0005 | 80% | 80% |
Location=13.33(deg) | 0.0018 | 0.0020 | 0.0018 | 0.0018 | 11% | 11% |
Location=20.00(deg) | 0.0029 | 0.0030 | 0.0029 | 0.0029 | 3.45% | 3.45% |
Location=26.67(deg) | 0.0024 | 0.0021 | 0.0024 | 0.0024 | 12.5% | 12.5% |
Location=33.33(deg) | -0.0017 | -0.0016 | -0.0017 | -0.0017 | 5.88% | 5.88% |
Location=40.00(deg) | -0.0118 | -0.0120 | -0.0118 | -0.0118 | 1.69% | 1.69% |
Vertical Y-Displacement in feet at the Center Joints 43-49 | SAP90 | Theory | LARSA | OPENBRIM | PERCENT DIFFERENCE (LARSA vs. THEORY) | PERCENT DIFFERENCE (OPENBRIM vs. THEORY) |
|---|---|---|---|---|---|---|
Location=0.00(deg) | 0.046 | 0.045 | 0.047 | 0.0463 | 4.26% | 2.81% |
Location=6.67(deg) | 0.031 | 0.027 | 0.031 | 0.0309 | 12.9% | 12.6% |
Location=13.33(deg) | -0.013 | -0.018 | -0.013 | -0.0131 | 38.5% | 37.44% |
Location=20.00(deg) | -0.078 | -0.082 | -0.079 | -0.0786 | 3.8% | 4.3% |
Location=26.67(deg) | -0.155 | -0.155 | -0.157 | -0.1557 | 1.3% | 0.45% |
Location=33.33(deg) | -0.234 | -0.241 | -0.236 | -0.2341 | 2.1% | 2.9% |
Location=40.00(deg) | -0.307 | -0.309 | -0.309 | -0.3072 | 0% | 0.6% |