OS-V: 0270 Torsional Creep of Circular Shaft
This benchmark illustrates the structural response of a power law creeping material in a geometrical configuration subjected to pure torsion. OptiStruct examines strain at the edge of the shaft.
- Relaxation at constant twist
- Forward creep at steady twist rate
Relaxation at Constant Twist
Benchmark Model
- X, Y displacements given at all nodes of front face using cylindrical system: 0.002 mm
- Rotation is given at mid-side nodes: 0.001 radians
Uniform twist of 0.01 radians/unit length is held constant in time from 0 to 100s.
- Material Properties
- Young's modulus
- 10 GPa
- Poisson's ratio
- 0.3
- Creep law equation
- Equivalent creep strain rate
- Equivalent stress (Mises)
Nonlinear Static Analysis Results
OptiStruct | NAFEMS | Normalized Target Value | |
---|---|---|---|
Total Strain (*10-3) | 5.46 | 5.77 | 0.95 |
Creep Strain (*10-3) |
4.85 | 4.77 | 1.01 |
Model Files
The model file used in this example includes:
<install_directory>/hwsolvers/demos/optistruct/verification/Torsional_Creep_Relaxation_at_constant_twist.fem
Forward Creep at Steady Twist Rate
A steadily increasing twist is applied at constant rate to the shaft.
The stresses increase from zero to steady value. The loads, which cause this steady state behavior are referred as “primary” loads.
Benchmark Model
- X, Y displacements given at all nodes of front face using cylindrical system: 0.004 mm/unit time
- Rotation is given at mid-side nodes: 0.002 radians/unit time
- Material Properties
- Young's modulus
- 10 GPa
- Poisson's ratio
- 0.3
- Creep law equation
- Equivalent creep strain rate
- Equivalent stress (Mises)
Nonlinear Static Analysis Results
OptiStruct | NAFEMS | Normalized Target Value | |
---|---|---|---|
Total Strain (*10-2) | 1.62 | 1.7321 | 0.94 |
Creep Strain (*10-2) |
1.27 | 1.1693 | 1.094 |
Model Files
The model file used in this example includes:
<install_directory>/hwsolvers/demos/optistruct/verification/Torsional_forward_creep_at_steady_twist_rate.fem
Reference
NAFEMS Ltd, The Standard NAFEMS BENCHMARKS TNSB Volume 2, NAFEMS Ltd, Scottish Enterprise Technology Park, Whitworth Building, East Kilbride, Glasgow, United Kingdom, 1990