Speaker

Prof. Y. Lawrence Yao


Fellow of ASME, SME, and LIA

Columbia University, USA

 

 

 

 

Keynote Lecture: Advances in Design and Manufacturing of Metal Foam Sandwich Panels

 

Abstract: This study was focused on laser forming of metal foam sandwich panels into non-Euclidean (3D) geometries. It was investigated whether the knowledge about the 2D bending mechanisms translates to 3D deformation, and whether the combination of process parameters that were identified for 2D laser forming are still appropriate. Moreover, the impact of the laser scan length was determined by comparing different scan patterns that achieve the same 3D geometries. It was shown that a significant amount of 3D deformation could be induced for both the bowl and saddle shapes, the two most fundamental non-Euclidean geometries. Furthermore, it was demonstrated that knowledge regarding the process parameter combinations and the bending mechanisms translates from 2D to 3D laser forming. The amount of bending deformation was shown to increase with the laser spot size, since in-plane strains start to be induced in the top facesheet. 

 

Biography: Y. Lawrence Yao is Professor of Mechanical Engineering at Columbia University, where he directs the Advanced Manufacturing Laboratory.  Yao served as Chair of Mechanical Engineering Department at Columbia University between 2005 and 2011.  Yao has pioneered research in laser materials processing, including laser assisted removal, shaping, joining, and property modification of various materials, and innovative laser applications in renewable energy, biomedical, and art restoration fields.  Yao received the Milton C. Shaw Manufacturing Research Medal from American Society of Mechanical Engineers (ASME) in 2015 and the Blackall Machine Tool and Gage Award from ASME in 2006. Yao is a Fellow of ASME, SME and Laser Institute of America and currently serves as Editor, Journal of Manufacturing Science and Engineering of ASME.  Yao received Ph.D. from the University of Wisconsin-Madison. 

Prof. Bi Zhang

 

Fellow, The International Academy for Production Engineering (CIRP)

 

Fellow, The American

Society of Mechanical Engineers (ASME)

 

South University of Science and Technology of China, China

 

 

 

 

 

Keynote Lecture: Material Responses to Loading at High Strain-Rates

 

Abstract: Material embrittlement is often encountered in machining, heat treatment, hydrogen and low-temperature conditions among which machining is strain-rate related. It can be a result of an enhanced strength and hardness, and a reduced fracture toughness of a material. Strain-rate evoked embrittlement can occur in a material subjected to high strain-rate loading (e.g., high-speed machining and projectile penetration). Loading to a material at a high strain rate (> 103 s-1) leads to material embrittlement which in turn contributes to the “skin effect” of material damage. This presentation is concerned with the strain-rate evoked material embrittlement and the “skin effect” of damage distribution in a material under high strain-rate loading. Empirical and physical models are compared for the assessment of the material embrittlement and damage. Strain-rate sensitivity is used to characterize material embrittlement and the concept of pseudo embrittlement is proposed for understanding material responses to extremely high strain rates. Material embrittlement and “skin effect” of damage are discussed in terms of dislocation kinetics and crack initiation and propagation. It provides guidance to predicting the material deformation and damage at a high strain-rate for applications ranging from the armor protection, quarrying, petroleum drilling, and high-speed machining of engineering materials (e.g., ceramics and SiC reinforced aluminum alloys).

 

Biography: Bi Zhang is currently a Chair Professor and the Associate Dean for Academic Affairs in the College of Engineering at the Southern University of Science and Technology in China. He received his M.S. and Ph.D. degrees from Tokyo Institute of Technology in Japan. Professor Zhang has been working on precision and ultra-precision machining and achieved notable academic attainments in machining of difficult-to-machine materials. He proposed the material response mechanisms based on pulverization in grinding of hard and brittle materials, which was world-wide accepted.

Starting from 1992, he was an Assistant Professor, Associate Professor and Full Professor with the University of Connecticut, USA. He also served as the Director of the Precision Machine Tool Center, the Director of the Management and Engineering for Manufacturing, and the Director of the Undergraduate Studies, all at the University of Connecticut. Since 2014, he has worked at Dalian University of Technology and Southern University of Science and Technology in China, respectively. Professor Zhang is a fellow of the International Academy for Production Engineering (CIRP), a fellow of the American Society of Mechanical Engineers (ASME), and a Standing Committee Member of the Production Engineering Institution of the Chinese Mechanical Engineering Society (CMES). He is an author of over 200 archived papers and 13 patents.

Prof. Raj Das

 

Deputy Chair of the 'National Committee on Applied Mechanics' of Engineers Australia

 

RMIT University, Australia

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Keynote Lecture:Characterising the mechanical properties of a new memory foam for biomedical applications

Abstract: The paper examines the evaluation of a new foam material (known as Hygroflex) in relation to its mechanical properties compared to a number of existing foams. The primary aim was to evaluate Hygroflex foam in regard to pressure redistribution under body induced deformation. More specifically, it explores Hygroflex’s pressure redistribution capacity for mitigation of pressure ulcer development due to long exposure to medical mattresses. The mechanical properties tested were those which play a vital role for use of foam in mattresses, especially medical mattresses used in hospitals. Five different variants of foam were subjected to different mechanical tests in order to evaluate their performance in relation to deformation and stiffness under simulant body part induced loadings. For example, loads exerted by a hip or ankle were replicated using simulant body parts, and the corresponding; deformation, contact development and pressure distribution around the respective simulant body parts were recorded. The properties of interests were; the peak pressure generated, pressure re-distribution over the immersed surface of the foam in contact with the simulant body part, and the immersion and wrap effects under body part induced deformation. The mechanical tests conducted were; a sharp indentation test, an envelopment test, a bulbous indentation test, shear tests, a roller arm test, and a cyclic test. A thermal test was also conducted to assess the heat dissipation ability of the various foams. The test results demonstrate that the newly developed Hygroflex foam has superior mechanical properties required in medical mattresses.

 

Biography: Dr Raj Das is a faculty member in the Aerospace and Aviation department of RMIT University, Australia and an honorary academic in the University of Auckland, New Zealand. He is a principal investigator of the ‘Sir Lawrence Wackett Aerospace Research Centre’ of RMIT University. He is an adjunct academic of the University of Quebec, Canada. He is the Deputy Chair of the ‘National Committee on Applied Mechanics’ of Engineers Australia.
Dr Das has published more than 200 papers in international journals and conferences. Dr Das has a PhD from Monash University, Australia in Structural Optimisation and Failure Analysis. Dr Das has previously worked in the University of Auckland, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), and the University of Manchester.
Dr Das has research capabilities in advanced materials, such as metamaterials, auxetic materials, architected materials, composite materials, topology and shape optimisation for materials and structural designs, computational modelling, fracture mechanics, dynamic fracture, damage tolerance based optimisation, numerical modelling and multi-scale analysis using finite element and mesh-less methods, impact behaviour and failure analysis of metals, ceramic and composite materials.

Dr Das has been granted several national and international awards and fellowships, including the ‘Jim & Hazel D. Lord Emerging Faculty Fellowship’, ‘Research Excellence Award’, and ‘AUEA Emerging Researcher Award’ by the University of Auckland. He has received the ‘CONICYT award’ from the Government of Chile, ‘Certificate of Merit Award’ from the International Association of Engineers, Hong Kong, ‘UQAC Visiting Fellowship’ from the University of Quebec, Canada, and ‘Visiting Researcher Fellowship’ from the University of Cape Town, South Africa.

 

 

 

 

 

 

 

 

 

 

 

D2ME Past Speakers

Prof. Gong Hao

National University of Singapore, Singapore

 

 

Prof. Zhan Chen
Auckland University of Technology, New Zealand

 

Prof. Ooi Kim Tiow

Nanyang Technological University, Singapore

 

Prof. Qinghua Qin
The Australian National University, Australia

 

Prof. C. W. LIM

City University of Hong Kong

 

 

Dr Raj Das

RMIT University, Australia

 

 

         

Prof. Josua Meyer

University of Pretoria, South Africa