OS-V: 0010 Elliptic Membrane

Test No. LE1 The model is a thin plate of thickness 0.1m subjected to a uniform pressure for linear static analysis. OptiStruct examines the direct stress σ y y at the point on inside the ellipse on the x-axis.



Figure 1.

Benchmark Model

Second order Hexahedral, Penta, Tetra, Quad and Tria elements are used to create the coarse and fine mesh. A uniform outward pressure of 10 MPa is applied on the outer face. The pressure is converted to force and is applied to the nodes for Quad8 and Tria6 elements.

The material properties are:
Young's Modulus
210 x 103 MPa
Poisson's Ratio
0.3

Linear Static Analysis Results

All results are normalized with the target value (92.7 MPa).
  Direct Stress σ y y at Point D (MPa) Normalized with the Target Value
Solid Hexahedral    
Hex8 coarse 63.15 1.467933492
Hex20 coarse 87.46 1.059913103
Hex8 fine 79.8 1.161654135
Hex20 fine 91.01 1.018569388
Solid Wedges:    
Penta6 coarse 48.68 1.904272802
Penta15 coarse 95.21 0.973637223
Penta6 fine 67.3 1.377414562
Penta15 fine 94.28 0.983241409
Solid Tetrahedral:    
Tetra4 coarse 53.34 1.737907762
Tetra10 coarse 95.96 0.966027511
Tetra4 fine 66.56 1.392728365
Tetra10 fine 95.28 0.972921914
Quad Shells:    
Quad4 coarse 61.83 1.499272198
Quad8 coarse 86.67 1.069574247
Quad4 fine 79.7 1.163111669
Quad8 fine 91.48 1.013336248
Triangular Shells:    
Tria3 coarse 54.06 1.714761376
Tria6 coarse 97.07 0.954980942
Tria3 fine 74.21 1.249157795
Tria6 fine 96.64 0.959230132

Model Files

The model files used in this example include:

<install_directory>/demos/hwsolvers/optistruct/verification
  • /LE1Hex8C.fem
  • /LE1Hex20C.fem
  • /LE1Hex8F.fem
  • /LE1Hex20F.fem
  • /LE1Pen6C.fem
  • /LE1Pen15C.fem
  • /LE1Pen6F.fem
  • /LE1Pen15F.fem
  • /LE1Tet4C.fem
  • /LE1Tet10C.fem
  • /LE1Tet4F.fem
  • /LE1Tet10F.fem
  • /LE1Quad4C.fem
  • /LE1Quad8C.fem
  • /LE1Quad4F.fem
  • /LE1Quad8F.fem
  • /LE1Tria3C.fem
  • /LE1Tria6C.fem
  • /LE1Tria3F.fem
  • /LE1Tria6F.fem

Reference

NAFEMS Ltd, The Standard NAFEMS BENCHMARKS TNSB Rev. 3, NAFEMS Ltd, Scottish Enterprise Technology Park, Whitworth Building, East Kilbride, Glasgow, United Kingdom, 1990.