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Author

Cheng Wang

Bio: Cheng Wang is an academic researcher from Beijing Institute of Technology. The author has contributed to research in topics: Detonation & Euler equations. The author has an hindex of 15, co-authored 66 publications receiving 826 citations.

Papers published on a yearly basis

Papers
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Journal ArticleDOI
TL;DR: Numerical tests indicate that the third order DG scheme with the new positivity-preserving limiter produces satisfying results even without the TVB limiter, which is a simpler and more robust implementation than the one proposed recently.

133 citations

Journal ArticleDOI
TL;DR: In this paper, a series of quasi-static compression tests were performed at ambient temperature, 200°C, 400°C and 600°C with a strain rate of 10 −3 ǫ s −1.
Abstract: The compression behavior of Ti–6Al–4V lattice structure with a cell shape of rhombic dodecahedron, which was fabricated by electron beam melting, was investigated at different temperatures. A series of quasi-static compression tests were performed at ambient temperature, 200 °C, 400 °C and 600 °C with a strain rate of 10 −3 s −1 . Two groups of design configurations were adopted by changing the cell size and thickness of struts with the sample size maintained unchanged. The results revealed that their properties varied with different cell sizes and temperatures. Larger cell size leaded to lower modulus and strength of the lattice. Higher temperatures resulted in lower strengths, modulus, densification strains and plateau stresses. The energy absorption of lattice at high temperature was discussed, and the experimental data were compared with aluminum foams, titanium foams and stainless steel lattice. It demonstrated that the rhombic dodecahedron Ti–6Al–4V lattice structure could be applied as load-bearing components and energy absorber at high temperature.

107 citations

Journal ArticleDOI
TL;DR: A simplified and improved implementation for this procedure, which uses the relatively complicated ILW procedure only for the evaluation of the first order normal derivatives, and fifth order WENO type extrapolation is used for all other derivatives, regardless of the direction of the local characteristics and the smoothness of the solution.

101 citations

Journal ArticleDOI
TL;DR: In this article, the compressive behavior of Ti-6Al-4V lattice structures with rhombic dodecahedron unit cells is investigated at four different strain rates, and the peak stress exhibits a certain dependence on the loading rate for the structures with smaller unit cells.

99 citations

Journal ArticleDOI
TL;DR: In this article, the authors developed a three-dimensional parallel solver using the fifth order high-resolution weighted essentially non-oscillatory (WENO) finite difference scheme to perform extensive simulation for 3D gaseous detonations.

67 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the authors examined three-dimensional metallic lattices with regular octet and rhombicuboctahedron units fabricated with geometric imperfections via Selective Laser Sintering and found that each lattice exhibits a distinct failure mechanism that is governed not only by cell topology but also by geometric defects induced by additive manufacturing.
Abstract: This paper examines three-dimensional metallic lattices with regular octet and rhombicuboctahedron units fabricated with geometric imperfections via Selective Laser Sintering. We use X-ray computed tomography to capture morphology, location, and distribution of process-induced defects with the aim of studying their role in the elastic response, damage initiation, and failure evolution under quasi-static compression. Testing results from in-situ compression tomography show that each lattice exhibits a distinct failure mechanism that is governed not only by cell topology but also by geometric defects induced by additive manufacturing. Extracted from X-ray tomography images, the statistical distributions of three sets of defects, namely strut waviness, strut thickness variation, and strut oversizing, are used to develop numerical models of statistically representative lattices with imperfect geometry. Elastic and failure responses are predicted within 10% agreement from the experimental data. In addition, a computational study is presented to shed light into the relationship between the amplitude of selected defects and the reduction of elastic properties compared to their nominal values. The evolution of failure mechanisms is also explained with respect to strut oversizing, a parameter that can critically cause failure mode transitions that are not visible in defect-free lattices.

320 citations

Journal ArticleDOI
TL;DR: In this article, the authors discuss the progress to date in the improvement of the fatigue performance of cellular structures manufactured by additive manufacturing, especially metal-based, providing insights and a glimpse to the future for fatigue-tolerant additively manufactured architected cellular materials.
Abstract: Additive manufacturing of industrially-relevant high-performance parts and products is today a reality, especially for metal additive manufacturing technologies. The design complexity that is now possible makes it particularly useful to improve product performance in a variety of applications. Metal additive manufacturing is especially well matured and is being used for production of end-use mission-critical parts. The next level of this development includes the use of intentionally designed porous metals - architected cellular or lattice structures. Cellular structures can be designed or tailored for specific mechanical or other performance characteristics and have numerous advantages due to their large surface area, low mass, regular repeated structure and open interconnected pore spaces. This is considered particularly useful for medical implants and for lightweight automotive and aerospace components, which are the main industry drivers at present. Architected cellular structures behave similar to open cell foams, which have found many other industrial applications to date, such as sandwich panels for impact absorption, radiators for thermal management, filters or catalyst materials, sound insulation, amongst others. The advantage of additively manufactured cellular structures is the precise control of the micro-architecture which becomes possible. The huge potential of these porous architected cellular materials manufactured by additive manufacturing is currently limited by concerns over their structural integrity. This is a valid concern, when considering the complexity of the manufacturing process, and the only recent maturation of metal additive manufacturing technologies. Many potential manufacturing errors can occur, which have so far resulted in a widely disparate set of results in the literature for these types of structures, with especially poor fatigue properties often found. These have improved over the years, matching the maturation and improvement of the metal additive manufacturing processes. As the causes of errors and effects of these on mechanical properties are now better understood, many of the underlying issues can be removed or mitigated. This makes additively manufactured cellular structures a highly valid option for disruptive new and improved industrial products. This review paper discusses the progress to date in the improvement of the fatigue performance of cellular structures manufactured by additive manufacturing, especially metal-based, providing insights and a glimpse to the future for fatigue-tolerant additively manufactured architected cellular materials.

238 citations

Journal ArticleDOI
TL;DR: The metal additive manufacturing (metal-AM) has undergone a remarkable evolution over the past three decades as mentioned in this paper, and it has moved into the mainstream of the industrialised field such as biomedicine.

231 citations

Journal ArticleDOI
TL;DR: In this article, the authors outline recent progress in the development of auxetic materials and structures, and their mechanical properties under quasi-static and dynamic loading are analysed and summarised.
Abstract: Different from conventional materials, materials with negative Poisson's ratios expand laterally when stretched longitudinally. Known as ‘auxetic’ materials, the effect means they possess particularly fascinating properties, which have recently attracted considerable attention in the literature. A range of auxetic materials has been discovered, theoretically designed and fabricated. Developments in additive manufacturing (AM) techniques enable fabrication of materials with intricate cellular architectures. This paper outlines recent progress in the development of auxetic materials and structures, and their mechanical properties under quasi-static and dynamic loading are analysed and summarised. Limited experimental studies on 3D printed auxetic materials and structures are given more attention, ahead of extensively finite element (FE) simulations. A special focus is dedicated to their large, plastic deformation behaviour and energy absorption performance, which should be stressed in their engineering applications; no review paper has yet been found regarding this. Finally, this paper provides an overview of current study limitations, and some future research is envisaged in terms of auxetic materials and structures, nano-auxetics and additive manufacturing.

214 citations

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TL;DR: A simple method to enforce the positivity-preserving property for general high-order conservative schemes is proposed for solving compressible Euler equations and a number of numerical examples suggest that this method can be used to prevent positivity failure when the flow involves vacuum or near vacuum and very strong discontinuities.

190 citations