Week 1 Spur Gear Challenge
Objective: Static Structural analysis for a Spur gear using three different materials. Compare the results obtain by using 3 different materials for Spure gear.
Solution:
Spur Gear: Spur gears are a cylindrical shaped toothed component used in industrial equipment to transfer mechanical motion as well as control speed, power, and torque. These simple gears are cost-effective, durable, reliable and provide a positive, constant speed drive to facilitate daily industrial operations.
The challenge given to us, is to run an analysis on a spur gear which is made of three differnet materials, i.e, Cast Iron, Cast Steel, Cast Bronze.
-Firstly, let's start with Cast Iron.
Material Property of Cast Iron:
Material Property of Cast Steel:
Material Property of Cast Bronze:
-Now, import the geometry to Ansys Workbench
-Now, open mechanical module, provide proper connections and run tests for Equivalent Stress, Total deformation, Equivalent Strain and Stress Intensity.
-Now, to make contacts
-Now, we assign joints for each gear by selecting their inner face and we choose the type as revolute.
-Now, we need to provide mesh for the geometry, for a fine mesh I have choosen 0.5mm as my element size.
-in Analysis settings we provide boundary conditions for the simulation.
-Now, assigning the two joint loads to the gears. Left gear will rotate 180 degrees, 30 degrees a step and the right gear will rotate at a moment of 10 N-m for all the six steps.
-As we are running this simulation to find out Equivalent stress, Total deformation and Stress intensity we provide all the three in the solution and run the analysis.
Cast Iron Equivalent Stress
cast Iron Equivalent stress graph
Cast Iron Total Deformation:
Cast Iron Total Deformation graph:
Cast Iron Stress Intensity:
Cast Iron Stress Intensity graph:
-Now, we change the material and run the same tests.
Cast Steel Equivalent Stress:
Cast Steel Equivalent Stress graph:
Cast Steel Total Deformation:
Cast Steel Total Deformation graph:
.
Cast Steel Stress Intensity:
Cast Steel Stress Intensity graph:
-Now, we change the material and run the same tests.
Cast Bronze Equivalent Stress:
Cast Bronze Equivalent Stress graph:
Cast Steel Total Deformation:
Cast Steel Total Deformation graph:
Cast Steel Stress Intensity:
Cast Steel Stress Intensity graph:
Stress Intensity: It is used to predict stress state(Stress Intensity) near the tip of a crack or notch caused by a remote load or residual stresses. It is a theoretical construct usually applied to a homogeneous, linear elastic material and is useful for providing a failure criterion for brittle materials, and is a critical technique in the discipline of damage tolerance. The concept can also be applied to materials that exhibit small scale yielding at a crack tip.
Table:
Materials Stress (MPa) Total Deformation(mm) Strain(mm/mm) Stress Intensity(MPa)
Cast Iron 462.74 30 0.0052423 521.4
Cast Steel 460.92 30 0.0028605 518.01
Cast Bronze 443.14 30 0.0068766 494.44
Spur gear Simulation:
Conclusion:
-As per the table shown above we can see that cast Iron is having highest stress amoung the three materials and as well as stress intensity, so we cannot Choose cast iron for Spure gear
-Cast Bronze is having less stress intensity but, Bronze is high in copst when compared between these three materials. So, we cannot choose Bronze either.
_So, we are left out with Cast Steel. Hence, from the table above we can see that cast steel is having moderate values when compared in between these three materials. So, it is best to choose Cast steel for manufacturing of spur gear.