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.

The solid element properties are:
FE Model
Rack Gear
Hexas and Pentas
Pinion Gear
Hexas and Pentas
The linear material properties are:
MAT1
Young’s Modulus
2.1E5
Poisson's Ratio
0.3
Initial Density
7.85E-9

Results

Figure 2 shows the initial and final positions of the rack and the pinion gears. The initial position is shown by the feature lines highlighted in black.


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