Group 5 James Pacey, Ray Brown, Brent Sutherland

Transcription

1 Group 5 James Pacey, Ray Brown, Brent Sutherland

2 Definition: To model a constant velocity birfield axle joint and shaft, and perform a stress analysis on the birfield Objectives: Gain further CAD experience with Solidworks and ANSYS, try more advanced techniques and focus on organization Analyze stress on the birfield using Solidworks simulator and ANSYS Try motion analysis and model rendering

3 Application: Used in front axle of four wheel drive vehicles Transmit torque from differential to wheel while allowing the wheels to steer Weak link with larger tires and low gearing

4 Exploded view of the axle assembly Inner bearing race Inner snap ring Birfield outer bell Outer snap ring Inner shaft Bearing Cage (6) Ball bearings

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6 Model ¼ or ½ of a circular part and use mirror to produce complete part Cut loft feature used to create splines Sweep cut along a spine to create bearing races Mating parts using sketch geometry FEA using ANSYS

7 Symmetry and mirror features were used to reduce file size and simplify part tree

8 Used two 3D sketch planes Cut loft between two planes to create a spline Circular pattern for rest of the splines

9 Sweep cut feature used for both inner and outer bearing races Circular pattern used to cut the rest

10 Measuring certain features on the actual parts to input into Solidworks Splines Elliptical bearing tracks Mating the ball bearings in the birfield assembly Difficult to constrain the bearings to stay in the races

11 Exported model geometry data using.iges Element type: 3- D 10- Node Tetrahedral Structural Solid (Solid 187) Well suited for complex shapes High order element (quadratic) Volume meshed using auto mesh. Birfield shortened to exclude most of the shaft to help increase mesh density in bell.

12 - Fixed the back face of the shaft - Applied forces at the contact points of the ball bearings. Location Ball Contact Point Shaft Fillet Ball Track Center Von Mises Stress 2 GPa 830 Mpa 515 Mpa

13 Loading applied to nodes closest to application points. Slight asymmetrical loading High contract stress due to point loads Due to concave application surface cluster points were difficult to apply. Loads closest to the application points were not always on the surface. Relatively coarse mesh Limited by student version Poorer resolution than desired Attempted multi- body solution Long running times System memory limitations encountered No- linear solutions often crashed the program

14 Solidworks FEA results Loca%on Stress Thin sec)on of outer bearing race 500 MPa Sha7 Fillet 750 MPa Ball Bearing Contact Point 1.8 GPa

15 Location ANSYS Solid Works % Difference Ball Contact Point 2 GPa 1.8 GPa 10 % Shaft Fillet 830 MPa 750 MPa 9.6% Ball Track Center 515 MPa 500 MPa 2.9% Program Advantages Disadvantages Simulation Express - Simple to implement - Allows integrated design - Limited options for problem setup - Less advanced output options ASYS Academic 12.0 Teaching Introductory - Allows more advanced analysis - Extremely customizable - Limited by intro version - Limited geometric manipulation - Steep learning curve

16 Model rendered using Solidworks Photoworks

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20 Gained more experience with Solidworks Using more complex features and techniques First time using Photoview rendering and model animation Gave us a chance to try ANSYS FEA

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