University of Wollongong Research Online University of Wollongong Thesis Collection 1954-2016 University of Wollongong Thesis Collections 2014 Study of shear thickening/stiffened materials and their applications Tongfei Tian University of Wollongong Follow this and additional works at: https://ro.uow.edu.au/theses University of Wollongong Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. The University does not authorise you to copy, communicate or otherwise make available electronically to any other person any copyright material contained on this site. You are reminded of the following: This work is copyright. Apart from any use permitted under the Copyright Act 1968, no part of this work may be reproduced by any process, nor may any other exclusive right be exercised, without the permission of the author. Copyright owners are entitled to take legal action against persons who infringe their copyright. 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For further information contact the UOW Library: [email protected] Study of Shear thickening/stiffened materials and their applications A thesis submitted in fulfillment of the requirements for the award of the degree of Doctor of Philosophy Tongfei TIAN Faculty of Engineering and Informatics Science, University of Wollongong July 2014 Wollongong, New South Wales, Australia CERTIFICATION I, Tongfei TIAN, declare that this thesis is submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy in the School of Mechanical, Materials & Mechatronic Engineering, Faculty of Engineering and Informatics Science at the University of Wollongong, and is wholly my own work unless otherwise referenced or acknowledged. The document has not been submitted for qualifications to any other academic institution. Tongfei TIAN 18 November 2014 - i - ACKNOWLEDGMENTS ACKNOWLEDGEMENTS I wish to express my sincere thanks to my supervisor, Professor Weihua Li. I could not imagine having a better advisor and mentor for my Ph.D study. He is a great scientist as well as a great person, who has given me his enthusiastic support, professional direction, and constant encouragement, and has inspired me to overcome the challenges on the road of life and study. I would also like to thank my co-supervisors Dr Jie Ding and Professor Gursel Alici for their supportive guidance and great advice, as well as Dr. Philips Whitten and Professor Zaiping Guo for providing professional discussion and offering experimental instruments for my thesis work. I am grateful to our group members: Mr Qing Meng, Mr Gangrou Peng and Mr Shuaishuai Sun for their assistance in my experiments. I also thank Dr Rahim Mutlu and Mr. Trung Duc Than who offered me endless discussion during my graduate studies. Without the assistance of my lab mates I could not have completed this dissertation. Particular thanks are extended to Dr Xianzhou Zhang for his helpful discussions for this project. Thanks are also extended to Keith Maywald, Doug Henness, Greg Tillman, Nick Mackie, Wayne Ireland, Stuart Rodd, and Ron Marshall for their technical assistance and kind discussions. Finally, I specially would like to thank my wife Jianli Liu, my daughter Yiran Olivia Tian, and my entire family for their understanding, patience, and unwavering support as they encouraged me to complete this thesis. - i - ABSTRACT ABSTRACT This thesis focused on the properties of shear thickening/stiffened materials and their applications. The fabrication of shear thickening fluid (STF) made from ethylene glycol and fumed silica was studied and its properties were measured with a rheometer under state steady and dynamic test conditions. The temperature effect on shear thickening fluid was also investigated and a numerical function was proposed to express the relationship between the temperature, viscosity, and concentration of fumed silica. Adding fumed silica to a currently used commercial electrolyte resulted in a shear thickening electrolyte with a higher ionic conductivity than the commercial electrolyte. Furthermore, the batteries using this shear thickening electrolyte provided extra mechanical protection than those batteries containing commercial electrolyte. The magnetorheological shear thickening fluids (MRSTFs) can be gained by combining the magnetorheological fluid (MRF) and shear thickening fluid. This new MRSTFs were tested and revealed both a magnetorheological effect and shear thickening properties. Moreover, the damper filled with MRSTF had unique properties coming from both magnetorheological fluid and shear thickening fluid. Shear stiffened elastomers (SSEs) made of silicone rubber and silicone oil were fabricated and observed by scanning electron microscope (SEM). A cluster structure was observed and the sample with a higher concentration of silicone oil had longer clusters of silicone rubber. The rheology of shear stiffened elastomers was measured with a rheometer and it showed that the sample with a higher concentration of silicone oil had a longer linear range and a lower shear modulus. During the dynamic frequency sweep tests when the shear strain amplitude was above a critical value, the shear stiffened elastomer sample was seen to change from solid to liquid and then from liquid to solid, which was the onset of shear stiffened. - i - TABLE OF CONTENTS TABLE OF CONTENTS CERTIFICATION ........................................................................................................ i ACKNOWLEDGEMENTS ......................................................................................... ii ABSTRACT ................................................................................................................ iii TABLE OF CONTENTS .............................................................................................. i LIST OF FIGURES ...................................................................................................... i LIST OF TABLES ....................................................................................................... 8 LIST OF SYMBOLS ................................................................................................... 9 LIST OF ABBREVIATIONS .................................................................................... 10 CHAPTER 1 INTRODUCTION ................................................................................. 1 1.1 BACKGROUND AND MOTIVATION ....................................................... 1 1.2 AIMS AND OBJECTIVES ........................................................................... 2 1.3 THESIS OUTLINE ....................................................................................... 2 CHAPTER 2 LITERATURE REVIEW ...................................................................... 4 2.1 INTRODUCTION ......................................................................................... 4 2.2 SHEAR THICKENING MATERIALS ........................................................ 4 2.2.1 Shear Thickening Fluids ........................................................................ 4 2.2.2 Carrier fluid and Particles ...................................................................... 6 2.2.3 Fabrication of STFs .............................................................................. 11 2.2.4 Other Shear Thickening Materials ....................................................... 12 2.3 RHEOLOGY OF STFs ............................................................................... 13 2.3.1 Steady-state and dynamic properties of STF ....................................... 14 2.3.2 Temperature Effect of STF .................................................................. 14 2.4 MECHANISM OF STF ............................................................................... 15 2.5 APPLICATIONS OF STFs ......................................................................... 17 2.5.1 Liquid body armour.............................................................................. 17 2.5.2 Devices with Adaptive Stiffness and Damping ................................... 18 2.5.3 Smart structures .................................................................................... 18 2.6 STF BASED DUAL- OR MULTI-FUNCTIONAL SMART MATERIALS 19 2.7 CONCLUSION ........................................................................................... 20 CHAPTER 3 SYNTHESIS, MECHANISM & TEMPERATURE EFFECT OF STFS .................................................................................................................................... 21 3.1 INTRODUCTION ......................................................................................