Jianjian Wang

Jianjian Wang
Tsinghua University | TH · Department of Mechanical Engineering

Doctor of Philosophy
Looking for postdocs and international Ph.D students.

About

63
Publications
15,513
Reads
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866
Citations
Introduction
My research interests center on next-generation manufacturing processes and equipment, now mainly focus on the fundamental understandings of process mechanics and principles of vibration machining; to achieve technological advances in vibration tool design and control; and to explore novel applications in vibration enhanced manufacturing. Positions for PhD and postdoctoral students are open now. Email me: wangjjthu@tsinghua.edu.cn
Additional affiliations
August 2020 - January 2021
Karlsruhe Institute of Technology
Position
  • Humboldt Research Fellow
October 2019 - present
Northwestern University
Position
  • PostDoc Position
August 2017 - October 2019
The Chinese University of Hong Kong
Position
  • PostDoc Position
Education
September 2014 - July 2017
Tsinghua University
Field of study
  • Mechanical Engineering
September 2011 - June 2014
Tsinghua University
Field of study
  • Instrument and meter engineering
June 2007 - June 2011
Shandong University
Field of study
  • Mechanical Engineering

Publications

Publications (63)
Article
Surface texturing using two-dimensional non-resonant vibration cutting tools (2-D NRVCT) has emerged as a promising method to fabricate micro-structured surfaces. The non-resonant vibration tool is able to work in a continuous frequency range with precise control of the tool trajectories compared with their resonant counterparts. The existing desig...
Article
Full-text available
This study investigates the ductile-to-brittle transition behavior in elliptical vibration cutting (EVC) of silicon and identifies the practical process window for ductile-regime cutting. EVC has been reported to increase the critical depth of ductile-regime cutting of silicon. This study demonstrates that the enhanced ductile cutting performance,...
Article
Full-text available
Structural coloration stemming from microstructure-induced light interference has been recognized as a promising surface colorizing technology, based on its potential in a wide array of applications, including high-definition displays, anti-counterfeiting, refractive index sensing, and photonic gas and vapor sensing. Vibration-assisted ultraprecisi...
Article
Full-text available
Optically variable devices (OVDs) are well received for anti-counterfeiting and decorative applications. In this study, new strategies to develop highly decoupled OVDs were proposed and demonstrated based on the fast patterning of blazed gratings by vibration-assisted diamond texturing. A unique surface generation mechanism was revealed as a combin...
Article
The high-quality machining of Nomex honeycomb composites is challenging due to its intrinsic brittleness. The rotary ultrasonic cutting performed on Giant magnetostriction ultrasonic system (GMUS) has been recognized as a superior method for the high-quality machining of Nomex honeycomb, owing to its capability to generate large-amplitude ultrasoni...
Article
Full-text available
Ultrasonic elliptical vibration cutting (UEVC) is a superior machining method for difficult-to-cut materials. The shape of the elliptical tool trajectory crucially affects the integrity of the machined surface. However, the existing designs of UEVC tool typically suffer from difficult motion decoupling, resulting in the low controllability of ellip...
Article
Ultrasonic cutting is a superior machining process for brittle materials, owing to its capability to reduce the cutting force and improve the surface quality. To avoid the destructive instability of ultrasonic vibration induced by the cutting force, the excitation frequency of the ultrasonic system must reliably track its resonance frequency. Howev...
Article
Rotary ultrasonic machining is regarded as a superior machining method for hard and brittle materials. It utilizes ultrasonic tool vibration to improve the material machinability, resulting in reduced cutting force and improved machining efficiency. The temperature stability and resonance quality of the ultrasonic system are critical for the reliab...
Preprint
Full-text available
This study investigates the ductile-to-brittle transition behavior in elliptical vibration cutting (EVC) of silicon and identifies the practical process window for ductile-regime cutting. EVC has been reported to increase the critical depth of ductile-regime cutting of silicon. This study demonstrates that the enhanced ductile cutting performance,...
Preprint
Full-text available
Fabrication of nickel-titanium shape memory alloy through additive manufacturing has attracted increasing interest due to its advantages of flexible manufacturing capability, low-cost customization, and minimal defects. The process parameters in directed energy deposition (DED) have a crucial impact on its molten pool characteristics (geometry, mic...
Article
Fabrication of nickel-titanium shape memory alloy through additive manufacturing has attracted increasing interest due to its advantages of flexible manufacturing capability, low-cost customization, and minimal defects. The process parameters in directed energy deposition (DED) have a crucial impact on its molten pool characteristics (geometry, mic...
Article
Silica aerogel composite with ultralow density is a kind of highly porous solid with excellent property of thermal conductivity. It is widely used for thermal insulation in aerospace, national defense and military industries. However, silica aerogel composites are difficult to process, due to the poor mechanical properties, low strength and high br...
Article
Full-text available
Dispersion is a very common phenomenon in the broadband optical systems. Chromatic confocal technology uses the chromatic aberration of lens to decode the axial displacement of the sample surface by the focus-wavelength of the reflected spectrum. Dispersion characters of the light source and sample surface greatly influence the reflected spectrum e...
Article
Full-text available
Titanium alloy is a typical difficult-to-cut material due to its high strength and high stiffness. To solve the problem of the low efficiency and poor surface quality in the milling of titanium alloy, this paper proposes a novel longitudinal-torsional ultrasonic vibration milling (LTUVM) process. An ultrasonic horn with spiral slots was designed to...
Article
Due to the large magnetostrictive coefficient, high power density and fast response speed of giant magnetostrictive materials, the giant magnetostrictive ultrasonic transducer (GMUT) becomes an increasingly popular research topic in making a high-power ultrasonic vibration. However, due to the complex energy conversion mechanism of the GMUT, the op...
Article
Due to the large magnetostrictive coefficient, high power density and fast response speed of giant magnetostrictive materials, the giant magnetostrictive ultrasonic transducer (GMUT) becomes an increasingly popular research topic in making a high-power ultrasonic vibration. However, due to the complex energy conversion mechanism of the GMUT, the op...
Article
Hierarchical microchannels, which consist of the primary channel formation and superimposed secondary nanostructures, are attracting ever-increasing attention due to their unique capacity to enhance and modify the surface characteristics and functional performance. The mechanical machining methods for microchannel fabrication, such as micro-milling...
Article
Elliptical vibration texturing is a newly arising method for the fast and cost-effective generation of near-subwavelength micro-structures on metal surfaces. This study proposes a fabrication method for structurally colored basso-relievo by combining the surface sculpturing and elliptical vibration texturing in one-step machining. Synergistic modul...
Article
The technique of manufacturing surface micro-/nano- structures to colorize metal surfaces by using elliptical vibrating cutting has been continuously developed and has good industrial potential. However, the image rendering is based on a raster scan path and constant variation of cutting velocity. The process efficiency and stability are significan...
Article
Full-text available
A giant magnetostrictive rotary ultrasonic machine tool (GMRUMT) with a large and stable amplitude output was developed. The purpose of this study was to comprehensively evaluate the performance and technological characteristics of the GMRUMT by conducting large amplitude experiments of rotary ultrasonic machining. Combined with the transducers’ ch...
Article
Full-text available
Beryllium is a rare metal with many excellent properties, which make it increasingly meaningful for manufacturing precise instruments especially in the aerospace industry. Most of the small size beryllium parts consist of microgrooves that play an important role during use. In this paper, we adopted electrochemical machining (ECM) technology to pro...
Article
Full-text available
Compliance-based matrix method (CMM) has been regarded as an efficient technique for output compliance modeling of the flexure hinge-based compliant mechanism, owing to its simplicity and high accuracy. However, this study demonstrates that CMM is not always valid due to the intrinsic ill-condition of the compliance matrix of right circular flexure...
Article
Full-text available
The rotary ultrasonic machining (RUM) is a superior method for the high-efficiency, precise and low damage machining of advanced aviation materials. In the conventional RUM, an ultrasonic-frequency longitudinal vibration is utilized on the high-speed rotational tools. However, in the rotary ultrasonic elliptical machining (RUEM), a 2-D elliptical v...
Article
Microstructured surfaces can reduce friction force between two contact pairs in relative motion under hydrodynamic contact. In this study, we evaluate the friction reduction performance of microdimpled surfaces with different cross-sectional profiles generated by nonresonant modulation cutting. Computational fluid dynamics simulation was conducted...
Article
Full-text available
Drilling of ceramics matrix composites (CMCs) still faces challenges such as low efficiency and severe delamination. Reduction in cutting force is beneficial for improvement in drilling efficiency and suppression of delamination. Conventional rotary ultrasonic drilling (Con-RUD) using longitudinal vibration is regarded as a superior method for dril...
Article
Rotary ultrasonic machining (RUM) is a superior hole-manufacturing method for ceramic matrix composites (CMC) with reduced cutting force and improved hole quality. Among various processing parameters, sufficient and stable ultrasonic vibration is crucial to guaranteeing RUM effectiveness in terms of cutting force reduction. This study was devoted t...
Article
The machining induced edge chipping of hole manufacturing restricts the productivity and design capability of products made from brittle materials. Rotary ultrasonic machining (RUM) has been sufficiently proved as a suitable approach for hole drilling in brittle materials with reduced cutting force and improved hole edge quality. However, apparent...
Article
Rotary ultrasonic drilling (RUD) has been fully proved to be superior in hole-manufacturing of brittle materials and composites with reduced cutting force and improved machining quality. This paper was devoted to the proposition of a novel index for the design and manufacturing of an ultrasonic machine tool (RUMT), called the critical cutting force...
Article
Full-text available
In order to further improve the processing performance of rotary ultrasonic machining (RUM), a novel longitudinal-torsional coupled (LTC) vibration was applied to the RUM. An experimental study on quartz glass was performed to access the feasibility of the LTC-RUM of a brittle material. The LTC-RUM was executed through the addition of helical flute...
Article
Rotary ultrasonic machining (RUM) combines diamond grinding with small-amplitude tool vibration, to improve machining processes of hard and brittle materials. It has been successfully applied to the machining of a number of brittle materials from optical glasses to advanced ceramics as well as ceramic matrix composites. The emphasis of this literat...
Article
The carbon fibers fracture mechanism depending on fiber orientation significantly affects the machined surface integrity of C/SiC composites. Rotary ultrasonic machining (RUM) has been proved to be a beneficial method for C/SiC composites drilling with minor tearing defects at hole exits. However, the effects of tool vibration on surface integri...
Article
For the purposes of estimation and control of the vibration amplitude in rotary ultrasonic machining, the relation between vibration amplitude and excitation signal was examined. The mechanical components outside the Terfenol-D were regarded as a single-degree-of-freedom mass spring damping system, and an equivalent mechanical model of the giant ma...
Article
Full-text available
Rotary ultrasonic machining (RUM) is a mechanical type of nontraditional hybrid machining process that combining the material removal regime of both ultrasonic machining and conventional grinding. By utilizing the RUM of hard and brittle materials, superior processing outcomes can be realized, such as improved material removal rate, reduced cutting...
Conference Paper
The feasibility of rotary ultrasonic face milling (RUFM) of ceramic matrix composites was evaluated experimentally in this study. Preliminary experimental results show that, comparing with conventional grinding (CG), RUFM can reduce cutting forces dramatically though with a little enlargement of surface roughness. Both in CG and RUFM, a positive de...
Article
Full-text available
The mechanical machining induced edge chipping at hole exit restricts the applications of brittle materials. Rotary ultrasonic machining (RUM) is regarded as a suitable approach for the holes-manufacturing of brittle materials with reduced edge chipping, comparing with conventional grinding. However, obvious edge chipping can still be observed in R...
Article
Rotary ultrasonic machining (RUM) is a well-known and efficient method for manufacturing holes in brittle materials. RUM is characterized by improved material removal rates, reduced cutting forces and reduced edge chipping sizes at the hole exit. The aim of this study is to investigate the critical feed rate to guarantee the effectiveness of RUM. E...
Article
Drilling induced tearing defects at the hole exit restrict the reliability of C/SiC production. In this study, the drilling induced tearing defects in rotary ultrasonic machining of C/SiC composites were investigated quantitatively. The mechanism of tearing defect formation was studied through the detailed observation of thrust force. Experimental...
Article
The precision cylindrical traverse grinding process of slender bar is very complex for the strongly time dependent properties of the wheel. Therefore, it is very difficult for operators to properly judge the grinding state using naked eyes and ears. This calls for automatic monitoring technology that can monitor the process in precision cylindrical...
Article
In order to improve the centering accuracy of wedge - hook power chuck, the grouping exchange method for assembling the chuck body and wedge plunger was developed, on the basis of the principle of grouping exchange method and actual production requirement. Using this method, series of power chucks were produced. Experiments on the centering accurac...
Article
Based on the clarification of the effect of chucking arc angle on the contact status of chuck jaw and workpiece, and on the radial chucking stiffness, the tilting angles of chuck jaw with different operation parameters and structure parameters were investigated. And the model of chucking arc angle produced by turning was developed. For the two diff...
Article
The edge chipping of holes, which is induced by mechanical machining, restricts the applications of brittle materials. Rotary ultrasonic machining is considered a suitable approach to machine holes in brittle materials with a smaller edge-chipping size. However, obvious edge chipping at the hole exit in rotary ultrasonic machining remains observabl...
Article
Mechanical-machining-induced tearing defects at hole exits restrict the application of C/SiC composites. Rotary ultrasonic machining (RUM) is suitable for hole manufacture in brittle composites, providing reduced tearing size as compared with conventional grinding. Even so, substantial tearing defects at the hole exit remain with RUM. In this study...
Article
Ultrasonic vibration is assumed to be stable or unchangeable during the process of rotary ultrasonic machining (RUM) on brittle materials, neglecting the effects of different processing parameters. However, no experimental evidence has been reported to validate this assumption. In this study, the effect of thermomechanical load on the stability of...
Article
To improve the accuracy preservation of three-jaw chuck, the effect of abrasion of chuck components on its centering accuracy was investigated. And the model of centering accuracy and repeatability of three jaw chuck was developed. Among the position errors of jaws induced by abrasion of chuck components, the radial position errors dominates. For t...
Article
Edge chipping induced by the mechanical machining of holes in brittle materials restricts the applications of the brittle materials. Rotary ultrasonic drilling is a suitable approach for the machining of holes in brittle materials with a smaller size of edge chipping. A good understanding of the mechanism of edge chipping reduction when employing r...
Article
Based on the clarification of chucking rigidity's influence on the chucking accuracy, the characteristic of chucking rigidity is researched systematically. Putting the contact state of chucking arc and workpiece, the influence of clamping force, chucking length, and bending force on the radial chucking rigidity is analyzed. The investigation shows...
Article
Edge chipping induced by rotary ultrasonic drilling (RUD) restricts the applications of brittle materials. It should be possible to reduce or eliminate edge chipping by optimizing the process parameters based on efficient theoretical modeling of the size of the edge chip. However, to date, no publications are available on the predictive modeling of...
Article
Subsurface damage (SSD) induced by the rotary ultrasonic face machining (RUFM) considerably influences the technological application of the optical components. However, currently, there is no method to detect the depth of SSD in real time. For the purpose of precise and nondestructive evaluation of the SSD depth generated in RUFM processes, a predi...
Article
The progressive development of hard turning technology places greater demands upon clamping devices. The chuck is required not only to grip the workpiece securely but also to have high and stable radial chucking stiffness to guarantee high machining accuracy. As a primary property of a chuck, the clamping force, which greatly affects the security a...
Article
By using theoretical modeling, simulation and experiment, the static clamping force characteristics was studied in terms of the operation parameter, structural parameter, lubrication conditions, and strength of the wedge type power chuck. The investigation performed showed that friction, especially the friction taking place on the contact surface b...
Article
In order to study the static clamping characteristics of power-operated compensating chuck, a mathematic model for the clamping efficiency and compensating dosage of the chuck was developed. The investigation performed shows that the clamping efficiency of chuck not only directly affects the coefficient of force transfer but also the stability of s...
Article
Nonuniform distribution characteristics of random points generated by Monte Carlo method in the workspace of parallel manipulators were discussed. Based on the density of distribution of the multiple random variable function, the relationship between Jacobian matrix and the probability density function of workspace points generated by Monte Carlo m...
Article
To improve the static chucking precision of power-chuck, considering four precision parameters and nine consistency factors, the tolerance of modeling method combining multi-body system theory is introduced. The repositioning precision analysis of single chuck, key factors of the consistency control and the centering accuracy of the turning top jaw...

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Projects

Projects (7)
Archived project
To develop a new manufacturing technology for fast and cost-effective creation of sub-micron scale grating structures on mold surfaces for structural coloration.
Archived project
In this project, we would develop a novel rotary ultrasonic elliptical machining method. Different from conventional elliptical method, the ultrasonic elliptical vibration is excited in the end face of diamond core tool. By applying this method, the processing performance of rotary machining method would be further improved with cutting force further reduction by 50%~80%, and hole exit defect reduction by 50%.
Archived project
In this project, we would develop non-resonant elliptical vibration tool, and use it to help investigate the material removal mechanism of elliptical cutting of brittle material, as well as texturing.