1. AVTC Model Based Design Curriculum Development Project

2. DFMEA Module 5

3. Introduction to DFMEA Design Failure Mode and Effects Analysis Use of DFMEA – New designs – Modifications to current designs – Use of a current design in a new environment, place or application Why? – To understand failures that may happen in an electric motor. Source: www.kookerkids.com/Coloring/computers.computer_trouble.htm

4. Characteristics of DFMEA Minimizes probability of a failure, or to minimize its effects Should be initiated before, at design concept finalization, or before production starts Continuous iterative process Provides a system to document processes and designs DFMEA evaluates the faults of a product as a consequence of design weaknesses Problems or failures normally arise during production stage, but originate during planning and designing of the product

5. DFMEA is an application of the Failure Mode and Effects Analysis (FMEA) method specific to product design DFMEA Purpose Remediation & Product Improvement Name and Component Part No. Potential Failure Causes Potential Failure Mode Potential Failure Effects Component Function Parts List Design Requirements Durability and Reliability. Past FMEAs, field Data Data Process and Product Historic Data: Product Specs

6. DFMEA Process 1.Identify the components of a product 2.Identify possible failures and their effects 3.Assess severity of potential failure and causes of failure 4.Assess potential frequency of occurrence 5.Identify detection modes 6.Assess the detection of the failure. Calculate risk priority number (RPN = severity * occurrence * detection) 7.For potential failures with highest RPN, create mitigation plans 8.Once actions have been taken, recalculate the RPN to confirm failure risk has been reduced

7. DFMEA for Manual Transmission Line No: Function of Part Potential Failure Mode Potential Effects of Failure SEV Potential Cause OCC Current Design Controls Prevention DETRPN 1 Mounts : To hold transmission system Breakage or rust due to moisture Abnormal noise and vibration 4 Loose or broken transmission and engine mounts 2 Tighten or replace mounts 216 2 Transmission housing: To hold gear oil Aging of seal or gasket Oil leaks 3 Damaged oil seal or gasket 5 Replace 230 3 Clutch: Engage and disengaging of engine to drive transmission Improper shifting of gears Shifting hard or not possible 5 Clutch plate worn 4 Replace clutch 360 Throw out bearing failure 2 Replace throw out bearing 330

8. DFMEA for Automatic Transmission Line No: Function of Part Potential Failure Mode Potential Effects of Failure SEV Potential Cause OCC Current Design Prevention Controls Current Design Detection Controls DETRPN 1 Oil pump: provide hydraulic pressure Reduced pressure Transmission inoperative 5 Bearing failure 2 Visual Inspection Function test 550 4 Seal leak 2 Visual inspection Function test 540 2 Brakeband: Clamp planetary gear Wear on band Transmission fail to shift 8 Excessive torque 3 Visual inspection Function Test for band slipping 372 3 Valve body: route fluid Fluid blockage Fail to shift gears 6 ATF contamination from overheating 3 Replace fluid and filter Inspect fluid and filter 472 4 Planetary gears Gear teeth breakage Transmission inoperative 8 Excessive torque, load and duration too long 2 Minimize excessive loads, especially towing ATF at excessive temperature 348

9. DFMEA for Continuous Variable Transmission Line No: Function of Part Potential Failure Mode Potential Effects of Failure SEV Potential Cause OCC Current Design Prevention Controls Current Design Detection Controls DETRPN 1 Driven Pulley Pulley flange become loose or cracked Pulley transmission stop working 8 More stress on pulley than needed 3 Check periodically if riveted flange need replacement Inspection 496 2 BeltBecome loose, worn, or break Transmission could stop working 8 More tension than needed 5 Check if belt needs replacement periodically Replace belt 4160 Excessive torque from load 7 Minimize excessive loads, no towing Inspection 4224

10. References “Design Failure Modes Effects Analysis (DFMEA)” http://www.clemson.edu/ces/crb/ece495/past_projects/MineSweeper/Fall2012/Gr oup1/dfmea.pdf. “Failure Modes and Effects Analysis (FMEA),” http://homepages.cae.wisc.edu/~me349/fmea/fmea_example4.pdf, 2000. Barry, Katy, “Avoid Failure When Using Failure Modes and Effects Analysis (FMEA), ” iSixSigma, http://www.isixsigma.com/tools-templates/fmea/avoid-failure-when- using-failure-modes-and-effects-analysis-fmea/, Aug. 2013. “FMEA Tutorial,” http://aaq.auburn.edu/node/501.

11. References “Automated Manual Transmission,” http://eex.gov.au/resource/potential-energy- efficiency-opportunities-in-the-australian-road-and-rail-sectors/automated-manual- transmission/. T. Ma, “Model-Based Control Design and Experimental Validation of an Automated Manual. Transmission,” M.S. thesis, Dept. of Mechanical Engineering, The Ohio State Univ., Columbus, OH, 2013, https://etd.ohiolink.edu/rws_etd/document/get/osu1374198354/inline. “Failure Mode and Effects Analysis,” http://www.scribd.com/doc/90988964/Failure- Mode-and-Effects-Analysis.