. ' L 5 / - ^ ^ / e3 / a i a i c i THE ANALYSIS OF SUITABLE FRAME (STRUCTURE) FOR A PEDAL CAR By MOLLIGODA M.L.C.Y. MORATUWA !! Supervised by Dr. M.A.R.V.FERNANDO This thesis was submitted to the Department of Mechanical Engineering of the University of Moratuwa in partial fulfillment of the requirements for the Degree of Master of Engineering in Manufacturing Systems Engineering Department of Mechanical Engineering University of Moratuwa Sri Lanka July 2006 U n i v e r s i t y o f M o r a t u w a I, II IIII 87886 8 7 8 8 6 DECLARATION This Dissertation paper contains no material which has been accepted for the award of any other degree or diploma in any University or equivalent institution in Sri Lanka or abroad, and that to the best of my knowledge and belief, contains no material previously published or written by any other person, except where due reference is made in the text of this Dissertation. I carried out the work described in this Dissertation under the supervision of Dr.M.A.R.V.Fernando. Date: 11 Name of Student: M.L.C.Y.Molligoda Registration No: 02/9631 (Supervisor's comments to be written here) Signature: Name of Supervisor: Dr. M.A.R.V.Fernando ii P R E F A C E The study on "Analysis of Various Body Shapes and Suitable Structure for a Pedal Car" carried out in partial fulfillment of the examination requirements of "Master of Engineering in Manufacturing Systems Engineering" postgraduate degree program. The design of the pedal car could be divided in to three categories as follows. II. The Analysis of Power Transmission System III. The Ergonomic Analysis The study was carried out to the best of my abilities and I hope the findings and recommendations, which are discussed in detail towards the latter part of the report, would be of some use to the future researches of this subject. I. Analysis Of Various Body Shapes And Suitable Structure For A Peddle Car IN ABSTRACT This study is mainly focused on to determine a suitable structure for the pedal car by considering following areas. 1. To determine the number of wheels for the pedal car 2. Driven drive (whether front or rear) 3. Number of wheels for steering "Tadpole car" is the final designed of the research because it is comparatively easy to fabricate and, there are so many advantages when fixing power transmission and steering mechanisms. Here the steering mechanism couples with front wheels of the "tadpole" structure. It governs by standard bicycle handle. End of the handle, by using two steel rods, couples with pin joint to the front wheels. Suspensions are necessary to maintain comfort-ability of the car. Therefore front wheels are assembled with two springs. And Rear wheel later part was assembled with pin joint and upper joint introduced with coil spring. This combination helps to maintain Constance distance between flywheel and the rear wheel. Brake must be with the vehicle to safe operation of it. Here all three wheels are controlled at the same time by jamming one liver. It is important for the stability of the vehicle while stopping. Steel Conduits are used for the fabrication of first embodiment. But after Cosmos analysis, it reveals that maximum stress occurred on the structure is 27 N/mra 2 . For Cosmos analysis, numbers of possible load combinations were applied on seat and paddles. Seat load considered as distributed load and pedal load took as point load Further this research can turn to another area of "law weight structures". Herein maximum efficiency can be achieved by reducing the body weight of the car. And it will help to popularize the car. Because generally riders like easy- handling vehicles. This goal would be achieved by replacing steel parts with Aluminum alloy or Timber structures wherever possible. iv Acknowledgments The research report bears the imprint of njany people. Initially my heartfelt gratitude is to my loving mother and my wife Chamari Molligoda for theirs loving support and guidance without which I would not be where I am today. My most sincere gratitude is offered to Dr. M.A.R.V. Fernando, senior lecture, Department of Mechanical Engineering, University of Moratuwa, for his mature guidance and concern without which this study would not have been possible. Particular thanks must go to Dr. G.K. Watugala, senior lecture, Department of Mechanical Engineering, University of Moratuwa, for many valuable insights and continues guidance and support given during my academic period for this study. My gratitude also goes to Mr. A. Edirisingha and Mr. Z. Shereefdeen for the support given to me as co- researchers. At last, to countless other people who have been generous with their time, support, and encouragement please know I am grateful to you all. T A B L E OF CONTENTS Page No Title i Declaration ii Preface iii Abstract vi ' Acknowledgments v Table of Contents vi-x CHAPTER 1 1.0 Overview 1 -4 1.1 Background of the Study 1 -5 CHAPTER 2 2.0 Literature Review 6 2.1 Energy Requirement for Pedaling 6 * 2.1.1 Energy - Power, Calories & Watts 7 2.1.2 Human Power for Pedaling 7-10 2.1.3 How Much Calories "Burn" While Cycling 10-11 2.1.4 Horizontal Distance Case Study 4 11-11 2.1.5 Vertical Distance (Hills) Case Study 11-12 2.1.6 Inertial Weight 4 12-13 2.1.7 Air Resistance, Wind, and Drafting 13-15 2.1.8 Shocks/Suspension 15-15 2.2 Chassis Frame "Tricycle" "Delta" Vs "Tad Pole" 16 > 2.2.1 Specific Properties of "Delta" Vs "Tad Pole" 16-18 2.3 Alternative Chassis Frames 18-30 2.4 The Weight vs. Wind Resistance 30-31 2.4.1 Derivation of Equations between the Weights 32-33 Vs. Wind Resistance 2.4.1.1 Simplified Formula 33-35 vi • 2.4.1.2 Hill-climbing Performance Comparison 35 2.5 Aerodynamics on Road Vehicles 36-38 2.6 Recumbent Seating Posture 38 2.6.1 History of the Recumbent 38-40 2.6.1.1 Stability Vs recumbent 40 2.6.2 Recumbent Performance 41 2.6.3 Manufacturability of Recumbent 41-42 2.6.4 Different Styles of Recumbent LWB, S WB, CLWB 42-43 2.6.5 Specific Application of LWB, S WB, CLWB 43 2.6.6 Ergonomics - Recumbent 44 2.6.7 Ergonomics - recumbent steering 45 2.6.8 General features of Recumbent 45-46 2.7 Finite Element and COSMOS 46-47 2.7.1 Finite Element Mesh 47 2.7.2 Finite Element Mesh Type 48 2.7.3 Finite Element -Loads and Boundary Condition 48 and the Analysis's 2.7.4 Example for Finite Element Calculation 49 CHAPTER 3 3.0 Governing Principles of Construction of Frame and Body 51 3.1 Introduction 51 3.2 Chassis Frame "Tricycle" "Delta" Vs "Tad Pole" 51-54 3.2.1 Influence of the wheelbase on tilting 54-55 3.3 Different Styles of Recumbent LWB, SWB, CLWB 55-57 3.3.1 Specific Application of LWB, SWB, CLWB 57 3.3.2 Ergonomics - Recumbent 58-59 3.3.3 Ergonomics - recumbent steering and wheels 59 3.4 Air drag when speed up 59-60 3.5 Finite element formula and matrixes 60-62 vii # CHAPTER 4 4.0 Methodology 63 4.1 Introduction 63 4.2 Frame configuration 63 4.3 Body Shapes 63 4.4 Critical Dimensions/ Recumbent 64 4.5 Fabrication of Model of the first Embodiment 64-65 4.6 Fabrication of first Embodiment 65 4.7 Selection of Various Load Combinations in Finite Element 65 4.2 Fabrication of the Pedal Car 68 CHAPTER 5 5.0 Test performance of the first prototype 71 5.1 Introduction 71-73 5.2 Speed Performance of the First Embodiment 74 5.3 Cosmos analysis 74-75 CHAPTER 6 6.0 Conclusion 76 6.1 General Overview 76 6.2 Achievements and Positive Aspects 76-77 6.3 Problems En-Countered and Limitations of the Study. 77 6.4 Recommendation 78 6.4.1 Roof and Cover Vs Ventilation 78 6.4.2 Further Development 79 6.5 Research for Further Studies 79 BIBLIOGRAPHY 80-82 APPENDIX A (Cosmos Results) 85-85 APPENDIX B (Material List and Manufacturing Cost) 86-87 APPENDIX C (Anthropometric Data) 88-89 APPENDIX D (3-D AutoCAD Drawing) 99-99 vm « List of Illustrations Page No. 1 Power required at various speeds for given rider parameters 10 2 Delta Structure 16 p 3 Tadpole Structure 16 4 Two front wheels, front steering, and rear wheel drive 20 5 Two front wheels, front steering, and rear wheel drive 20 6 Two front wheels, front steering, and front wheel drive 21 7 Two front wheels, rear wheel steering, and rear wheel drive 21 8 Two front wheels, rear wheel steering, and front wheel drive 22 9 Two rear wheels, front wheel steering, and rear wheel drive 23 10 Two rear wheels, front wheel steering, and rear wheel drive 24 11 Two rear wheels, front wheel steering, and front wheel drive 24 12 Two rear wheels, front wheel steering, and front wheel drive 25 * 13 Two rear wheels, rear wheel steering, and front wheel drive 25 14 Two rear wheels, rear wheel steering, and rear wheel drive 26 15 Two rear wheels, rear wheel steering, and front wheel drive 27 16 Two rear wheels, rear wheel steering, and front wheel drive 27 17 Two front wheels, front wheel steering, and rear wheel drive 28 18 Two rear wheels, rear wheel steering, and front wheel drive 29 19 Two front wheels, front wheel drive, and front and rear wheel 29 20 Distance Vs Vehicle Length 37 21 CLWB, LWB and SWB Structure 43 • 22 Finite Element Node 49 23 Delta Structure 52 24 Tadpole Structure 53 25 Tricycles with Two Wheels in the Front 55 26 CLWB, LWB and SWB Structure 57 27 Single Finite Element Nodes 61 • ix 28 Model of the Pedal Car 65 29 Analysis of how first embodiment is matched with anthropometrics 68 30 Fabrication of basic structure 38 31 Fabrication of basic structure 69 32 Fabrication of basic structure 69 33 At painting stage 69 34 Performance Testing 70 35 First embodiment of the pedal car 70 37 Critical Structure of the Pedal Car 72 38 Calculation 3-9 distances of the drawing 73 39 Basic Structure 74 x t List of Table Page No. 1 Combination of Tricycle 19 2 Definitions of Terms and Units 31 3 Performance Comparison 35 4 Types of Recumbent 42 5 Finite Element Mesh Type 48 6 Recumbent Type 56 7 Various Load in Finite Element 66 8 Critical Dimension of the Pedal Car 72 9 Finite Element Results 75 • xi