OS-E: 0115 Finite Sliding Contact
Nonlinear Analysis with finite sliding contact between rack and pinion gears.

Figure 1. FE Model with Contact Interfaces, Loads and Boundary Conditions
Model Files
Refer to Access the Model Files to download the required model file(s).
The model file used in this example includes:
rack_pinion.fem
Model Description
This example has only one nonlinear static load case where a rotation of 5 radians was applied to the pinion gear. The pinion gear engages with the rack using finite sliding contact causing the rack to move relative to the pinion, thereby translating the rotational motion of the pinion into linear motion.
The finite sliding contact between the rack and the pinion gears was defined with no friction and with surface to surface contact discretization.
There was also contact stabilization used to successfully solve the model. The default values on the CNTSTB Bulk Data card were used except for the S1 field, i.e. scale factor for stabilization coefficient at the end of a subcase where a value of 1e-6 was used.
- FE Model
- Rack Gear
- Hexas and Pentas
- Pinion Gear
- Hexas and Pentas
- MAT1
- Young’s Modulus
- 2.1E5
- Poisson's Ratio
- 0.3
- Initial Density
- 7.85E-9
Results

Figure 2. Initial and Final Positions of Rack and Pinion Gear

Figure 3. Displacement Results at Final Positions of Rack and Pinion Gear

Figure 4. Stress Results at Final Positions of Rack and Pinion Gear