Week 2 Railwheel and Track
Objective:
To perform a static structural analysis on a railwheel and track setup using two different bearing loads (100000N & 500000N) and compare the results for Total deformation, Euivalent stressand Fatigue life and also to Implement a User defined result and calculate the Total Deformation from this result and check if it is the same as that obtained by the inbuilt result by ANSYS for a load of 100000 N.
Case 1
For carrying out simulation we have selected structural steel as a material and the properties are as shown below.
In the contact region we have applied two different contacts the first one is frictional contact between wheel and the track and another one is a frictionalless contact between the wheel and the shaft.
In the joint section we have selected a fixed joint for the railtrack to restrict its motion. For the fixed joint the DOF is zero.
For the other joint we have used translation only to restrict its motion in only one direction as shown below the motion of the shaft will be in X direction.
For the third joint we have applied planar joint to the wheel having the DOF as 3. The figure below show the planar joint for the wheel.
For the mesh we have assigned a face mesh of 35mm for the faces in contact between the railtrack and the wheel where as other surfaces have been assigned with a mesh size of 50mm. The number of nodes for the analysis is 9740 and the element is 4936.
The analysis setting for the given simulation is shown below. Along with this setting we have set all yes in the output control sections.
For the loading purpose we have applied a bearing load of 100000N to the surface of the wheel in contact with the shaft in negative Y direction. The load has been applied in 5 steps.
We have also applied a displacement of 500m in the increment of 100m to the shaft as shown below.
Results:
Case1:(Bearing load 100000N)
Total deformation:
Equivalent stress:
Equivalent stress on the wheel:
Fatigue Life:
case 2: (Bearing load 500000N)
Total deformation:
Equivalent stress:
Equivalent stress on the wheel:
Fatigue Life:
Discussion:
| Total Deformation | Equivalent stress | Equivalent stress on wheel | Fatigue life | |
| Case 1 | 1002.6 mm | 122.6 MPa | 122.6 MPa |
1e6 -Max 1.536e5- Min |
| Case 2 | 1002.6 mm | 566.42 Mpa |
566.42 MPa |
1e6 - Max 1043.2 - Min |
- From the above table it is justified that the total deformation is almost same.
- The equivalent stress has increased in case 2 as the load applied has also increased. It can be seen that the maximum stress has occured at the wheel and track interface.
- From the Fatigue life data it can be observed that the minimum life in case 1 is 1.53e5 (almost near to inginite number of cycle) where as in the second case the life has decreased to 1043.2, which is the region of low cycle fatigue, hence chances of failure is catastropic in case 2.
User Defined Results:
Directional deformation is defined as deformation along particular axis where as Total deformation is resultant of all the directional deformation. This is the expression for Total deformation:
sqrt( ux^2 + uy^2 + uz^2) where ux, uy, uz are the directional deformation in x, y , z direction respectively.
For a bearing load of 1e5 we have calculated total and directional deformation and there after we have also calculated deformation through user defined data as shown below.
The total deformation calculated by the inbuilt system and by use defined results are same as shown below.
Total deformation calculated by the inbuilt system
Total deformation calculated by user defined result
From the above two image it can be seen that the user defined result and the result gnerated by the inbuilt are same.
https://drive.google.com/file/d/1229qtz6_uJT1u2uRDne5tnLih0VdpPWU/view?usp=sharing