AERx Pulmonary Drug Delivery System, Remmele Engineering, Inc. Steering Bracket Design Validation

2 © 2008 Dassault Systèmes SolidWorks Corp. Confidential. Steering Bracket Design Validation Goals Design for strength – Keep stress below 150 MPa Design for life – Last 1 million load cycles; last a season of 10~20 rallies Frequency Check – Avoid frequency in range 1 – 30 Hz The part is from a Group N rally car (modified road cars)

3 © 2008 Dassault Systèmes SolidWorks Corp. Confidential. Design for Strength Steering Force = 6000 N Hinges Setup Stress Plot FOS = 2.24 Normal

4 © 2008 Dassault Systèmes SolidWorks Corp. Confidential. Design for Life Optimized steering bracket should last for 1 million cycle load of 6000 N. Fatigue results show that around 38% of part life is used around hot spots

5 © 2008 Dassault Systèmes SolidWorks Corp. Confidential. Frequency Check Natural frequency of steering bracket shouldnt fall in range from 1 – 30 Hz. Under this road range vibrations are transferred to the driver through steering column. This should be avoided at all cost. Bracket design is safe and out of the frequency range of 1 – 30 Hz Mode shapes animation Mode No.Frequency(Hertz)

6 © 2008 Dassault Systèmes SolidWorks Corp. Confidential. Design Insight Use insight to make simple change to reduce weight Mention option of doing in context of assembly or at part level Can reduce weight by 7~10%

7 © 2008 Dassault Systèmes SolidWorks Corp. Confidential. Additional Demo - Design Optimization What would be the optimum design for a minimum factor of safety requirement? Bracket Weight 90.66g Reduced weight by ~10% Bracket Weight g Original Design Optimized Design Variable Settings: Radius = 8-12mm Thickness = mm Stress < 150MPa

8 © 2008 Dassault Systèmes SolidWorks Corp. Confidential. Additional Demo - Design Optimization Fatigue is impacted by the new design So 3.875mm thickness will not survive 1 million cycles