bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time-Invariant Deformation of Blood During Necking on an Electrowetting Digital Microfluidic Platform
Authors: Young Curtis , Ramasubramanian Anand K. , Simon Melinda , Lee Sang-Joon John 
Published: November 2019

Abstract
Recent developments in electrowetting-on-dielectric (EWOD) technology have expanded the possibilities for testing methods and investigation of blood. This work evaluated the development of necking geometry of whole blood on an EWOD-based digital microfluidic (DMF) platform. This was achieved by performing tensile tests on whole blood on an EWOD-based device, thereby inducing necking. A time-invariant method was used to evaluate the deformation of the tested dilutions, using minimum neck width and neck radius as two characteristic parameters of the necking geometry. Experiments were performed on blood diluted with phosphate-buffered saline (PBS) at dilutions of 1:20 and 1:10 by volume. Parameter measurements were obtained by recording microscope video of on-chip tensile tests and extracting the necking profile. Neck radius and neck width are obtained from the extracted necking profile and evaluated to compare results. Results from tensile tests on blood at different dilutions showed an exponential decrease in neck radius as neck width decreases. A four-parameter exponential model was fit to the collected data, showing that the 1:20 dilution had a higher neck radius to neck width ratio than the 1:10 dilution over a neck width interval of 0.3 mm to 1.7 mm, suggesting a viscosity effect on the necking geometry. The results demonstrate that the concentration of blood influences the necking profile when deformed under tension that is applied by electrowetting forces.
In-Situ Measurement of Liberation of a Dissolved Gas in Unsteady Cavitating Flow in Water
Authors: Makii Daiki , Sasaki Hirotoshi , Iga Yuka 
Published: November 2019

Abstract
Cavitation is a phenomenon in which phase change occurs in a liquid by pressure decrease due to flow acceleration. The phase change is caused by mainly evaporation of the liquid but sometimes by liberation of dissolved non-condensable gas in the liquid. In particular, unsteady cavitation causes vibration, noise, erosion and performance deterioration, which has been a serious problem in the development of fluid machinery. Therefore, it is important to research the characteristics of cavitation generation and develop methods to suppress or control it.
In the current CFD (computational fluid dynamics) model of cavitating flow, the saturated vapor pressure has been used as a criterion for determining the cavitation generation or disappearance based on the idea of phase equilibrium, however it is well known that these calculation results don’t agree well with experimental results. For example, it is reported that the cavitation inception pressure is higher than its saturated vapor pressure in water. This is predicted to be resulting from the generation of gaseous cavitation which is caused by liberation of dissolved air, however this has not been taken into consideration in the current CFD model. Here, liberation of non-condensable gas is supposed to be treated by MD (molecular dynamics) then it is not suitable for CFD. Thus, in order to develop a more accurate CFD model for cavitating flow, it is necessary to develop a macroscopic and coarse-grained model of liberation should be developed, which may be related to flow dynamic-stimulation of the unsteady flow field with cavitation.
In the present study, we focus attention on relationship between liberation of dissolved gas and unsteadiness of cavitation. Experiment is conducted in high-temperature water cavitation tunnel in which in-situ measurement of the amount of dissolved oxygen can be performed during the operation with cavitation. The variation of dissolved oxygen is used as one of the indexes of liberation of dissolved non-condensable gas during the experiment. The degree of cavitation unsteadiness is judged by calculation based on the FFT (Fast Fourier Transform) of the downstream fluctuation pressure and the RMS (root mean square) of brightness value using images taken with a high-speed camera. In addition, in order to eliminate the factors of dissolved gas liberation other than cavitation unsteadiness, the mainstream pressure, the mainstream temperature and volume of the cavity are made to be equal, respectively. Under the above preconditions, the time evolution of dissolved oxygen amount is measured in several kinds of cavitating flow fields around NACA0015 and NACA16012 hydrofoils.
Automatic Mobility Analysis of Parallel Mechanisms: An Algorithm Approach Based on Position and Orientation Characteristic Equations
Authors: Zhu Xiaorong , Shen Huiping , Wu Chengqi , Chablat Damien , Yang Tingli 
Published: November 2019

Abstract
The determination of the mobility of parallel mechanisms (PM) is a fundamental problem. An automatic and intelligent analysis software will be a significant tool for the design and optimization of mechanical systems. Based on the theory of position and orientation characteristics (POC) equations, a systematic approach to computer-aided mobility analysis of PMs is presented in this paper. First, a digital model for topological structures which has a mapping relationship with position and orientation characteristics of mechanism is proposed. It describes not only the dimension of the motion output, but also gives the mapping relationship between the output characteristic and the axis of the kinematic joints. Secondly, algorithmic rules are established that convert the union and intersection operations of POC into the binary logical operations and the automatic analysis of POC are realized. Then, the algorithm of the automatic mobility analysis of PMs and its implementation with VC++ are written. The mobility and its properties (POC) will also be analyzed and displayed automatically after introducing by users of the data of topological structures representation. Finally, typical examples are provided to show the effectiveness of the software platform.
Torsional Stiffness Model of an Industrial Robotic Joint Using Fractal Theory
Authors: Xu Jingjing , Liu Zhifeng , Zhao Yongsheng , Cheng Qiang , Pei Yanhu , Yang Congbin 
Published: November 2019

Abstract
It is known that mechanical connections have great influence on the dynamic characteristic of the assembly. In existing methods, the torsional stiffness of the robotic joint is calculated only considering the stiffness of components of the system, which largely reduces the prediction accuracy of the joint stiffness. In the paper, to predict the joint stiffness more accurately, a model is proposed considering influences of the stiffness of all connections existed in a joint system. The normal and tangential stiffness of the contact surface of each connection are calculated by combining the equilibrium analysis of the force and the fractal theory. Then the total stiffness of one robotic joint can be modelled by putting the torsional stiffness of all connections and that of the RV reducer and gear pair in parallel. To verify the proposed model, its simulation result is compared to the stiffness based on the previous technique without considering the influence of connections. The comparison result shows that the proposed model can improve the stiffness-prediction accuracy. This study can be extended to the stiffness modeling of other joint systems and provides a theoretical basis for the dynamic analysis of the robotic system.
Prediction of Out-of-Plane Rigid Ring Truck Tire Model Parameters Over Flooded Surface Using FEA-SPH Techniques
Authors: El-Sayegh Zeinab , El-Gindy Moustafa , Johansson Inge , Öijer Fredrik 
Published: November 2019

Abstract
This paper focuses on predicting the out-of-plane rigid ring model parameters of an off-road truck tire running over a flooded surface. The truck tire size 315/80R22.5 used in this study is modeled using Finite Element Analysis (FEA) technique and validated in static and dynamic responses. The flooded surface is modeled using Smoothed-Particle Hydrodynamics (SPH) technique and Murnaghan equation of state. The contact between the truck tire and a flooded surface is defined using node-symmetric node-to segment contact with edge treatment algorithm. The out-of-plane rigid ring tire model parameters include the lateral stiffness, cornering stiffness, self-aligning moment stiffness, and relaxation length. The out-of-plane rigid ring model parameters are computed at different operating conditions including various inflation pressures, vertical loads and water depth. The effect of the previously mentioned operating conditions on the tire-flooded surface interaction is examined and investigated.
Reliability Analysis of Nonlinear Vibratory Systems Under Non-Gaussian Loads Using a Sensitivity-Based Propagation of Moments
Authors: Papadimitriou Dimitrios , Mourelatos Zissimos P. , Patil Santosh , Hu Zhen , Tsianika Vasiliki , Geroulas Vasileios 
Published: November 2019

Abstract
This paper proposes a new methodology for time-dependent reliability analysis of vibratory systems using a combination of a First-Order, Four-Moment (FOFM) method and a Non-Gaussian Karhunen-Loeve (NG-KL) expansion. The vibratory system is nonlinear and it is excited by stationary non-Gaussian input random processes which are characterized by their first four marginal moments and autocorrelation function. The NG-KL expansion expresses each input non-Gaussian process as a linear combination of uncorrelated, non-Gaussian random variables and computes their first four moments. The FOFM method then uses the moments of the NG-KL variables to calculate the moments and autocorrelation function of the output processes based on a first-order Taylor expansion (linearization) of the system equations of motion. Using the output moments and autocorrelation function, another NG-KL expansion expresses the output processes in terms of uncorrelated non-Gaussian variables in the time domain, allowing the generation of output trajectories. The latter are used to estimate the time-dependent probability of failure using Monte Carlo Simulation (MCS). The computational cost of the proposed approach is proportional to the number of NG-KL random variables and is significantly lower than that of other recently developed methodologies which are based on sampling. The accuracy and efficiency of the proposed methodology is demonstrated using a two-degree of freedom nonlinear vibratory system with random coefficients excited by a stationary non-Gaussian random process.
Formalization of Fractional Flow Component in Higher-Order Logic Theorem Proving
Authors: Zhao Chunna , Jiang Murong , Huang Yaqun 
Published: November 2019

Abstract
Fractional calculus is a powerful tool for dealing with complex systems, and fractional flow component can effectively reflect the nonlinear gradual change of rheology in vibration state. Besides, higher-order logic theorem proving is a formal method for specification and verification. This paper, accordingly, presents a higher-order logic formalization of fractional flow component based on fractional calculus Caputo definition. The relationship between fractional order differential and integer order differential is verified according to fractional calculus Caputo definition in higher-order logic theorem proving, where fluid mechanics fractional flow component is then formally analyzed.
A New Approach to Compute Natural Frequencies and Mode Shapes of Non-Uniform Continuous Bar, Circular Shaft and Beam Vibration
Authors: Sinha Alok 
Published: November 2019

Abstract
The wave equation governing longitudinal vibration of a bar and torsional vibration of a circular shaft, and the Euler-Bernoulli equation governing transverse vibration of a beam were developed in the eighteenth century. Natural frequencies and mode shapes are easily obtained for uniform or constant spatial parameters (cross sectional area, material property and mass distribution). But, real engineering structures seldom have constant parameters. For non-uniform continuous structure, a large number of papers have been written for more than 100 years since the publication of Kirchhoff’s memoir in 1882. There are analytical solutions only in few cases, and there are approximate numerical methods to deal with other (almost all) cases, most notably Stodola, Holzer and Myklestad methods in addition to Rayleigh-Ritz and finite element methods. This paper presents a novel approach to compute natural frequencies and mode shapes for arbitrary variations of spatial parameters on the basis of linear time-varying system theory. The advantage of this approach is that now it can be claimed that “almost” closed-form solutions are available to find natural frequencies and mode shapes of any non-uniform, linear and one-dimensional continuous structure.
Non-Contact Vehicle Overload Identification Method Based on Body Vibration Theory
Authors: Ding Yiran , Zhou Daolin , Yu Shimin , Wang Zhenyu , Tan Gangfeng 
Published: November 2019

Abstract
Vehicle overload seriously affects the traffic safety, damages the road infrastructure, and the road service life is reduced. There are many shortcomings in the current detection methods for overloaded vehicles. Traditional static weighing stations are relatively fixed and affect the road traffic efficiency; the cost of weighing in motion station is high, while the precision is not enough; on-board weighing electronic products require the modification of vehicles, which is difficult to promote.
In this paper, a non-contact overload detection method based on body vibration is proposed. After the analyzation of the body vibration response of dynamic vehicles under specific vibrational excitation, the load value data can be obtained combined with standard parameters and mathematical calculation model. Firstly, the body vibration response model under specific excitation is established. Then, roadbed facilities are arranged according to specific requirements, cameras calibration are finished, and the identification environment is built. Machine vision technology is used to identify the vibration track of the characteristic point on the vehicle body in the vertical direction. The vibration response characteristic parameters are extracted using the established response model. Finally, the vehicle load value data can be obtained by resolve the characteristic parameters. Compared with the rated load data in the database, the overload judgment of the vehicle is obtained.
In the experiment part, the road speed-control hump was used as the vibration excitation source. The vehicle experiments were carried out with Dongfeng Aeolus S30 and Yuejin Shangjun X500. The results show that the load identification error can be controlled within 20%–30%. This method above can detect overload vehicles without affecting the traffic efficiency and also has certain guiding significance for the development of intelligent vehicles.
Tooth Root Shape Optimization of Thin-Rimmed Planet Gears
Authors: Chao Chen-Xiang , Bestle Dieter , Krüger David 
Published: November 2019

Abstract
Planetary gearboxes in highly sophisticated applications such as turbofan engines are required to have a high power-to-weight ratio and excellent reliability. Hence, thin-rimmed gear units need to be designed as compact as possible which, however, is usually limited by the tooth root load capacity. In order to come up with the best design, a tooth root shape optimization process is developed for thin-rimmed planet gears.
A Highly Manoeuvrable and Untethered Under-Actuated Legged Piezoelectric Miniature Robot
Authors: Hariri Hassan H. , Soh Gim Song , Foong Shaohui , Wood Kristin L. 
Published: November 2019

Abstract
This paper presents the design of a highly manoeuvrable and untethered under-actuated legged piezoelectric miniature robot called PISCES. It comprises of a piezoelectric patch bonded onto a thin diamond-shaped aluminium plate to form a planar unimorph piezoelectric actuator, with three rigidly attached legs to generate locomotion. Unlike other under-actuated robots found in literature which uses compliant mechanisms, our robot utilizes three different standing wave vibration modes of a thin diamond-shaped aluminium plate and well positioned rigid leg positions to achieve forward, clockwise rotation and anticlockwise rotation motion using a single piezoelectric patch. This approach have the benefit of generating a more predefined motion and thus more controllable.
A finite element analysis approach is proposed to understand the modal vibration of the 2D unimorph actuator and how the geometric placement of the rigid legs together with the robot center of mass can be utilized to achieve under-actuated planar locomotion is described in detail. To verify the proposed locomotion, PISCES of a size of 90 × 60 × 11 mm, weight of 21 g is built. It is able to achieve a linear speed of 203.5 mm/s for forward motion, an angular speeds of 7.7 Revolution Per Minute (RPM) for clockwise rotation and an angular speed of 10.6 RPM for anticlockwise rotation using an input sinusoidal voltage of 100 V amplitude. Under a payload of 100 g, it moves with a linear speed of 110.8 mm/s and angular speeds of 4.1 RPM clockwise and 12.5 RPM anticlockwise. A tether-less remotely driven PISCES featuring a full suite of onboard electronics, and a more detailed experimental verification, analysis and characterization of PISCES are also demonstrated in this paper.
Response Sensitivity in a Nonlinear Planetary Gear Set
Authors: Zhan Zhaobin , Liu Hui , Feeny Brian , Xiang Changle , Han Lijin 
Published: November 2019

Abstract
Due to the wide range of speeds of the vehicle engine, the resonance cannot be completely avoided. Aiming at this problem, the analysis of the dynamic characteristics of the vehicle transmission system is transferred from the analysis of the intrinsic characteristics to the analysis of the dynamic response, and the sensitivity analysis based on the dynamic response is derived. This study investigates dynamic response sensitivity to model parameters in a nonlinear single-stage planetary gear set coupled with lateral and torsional directions. The equations of response sensitivity are deduced with the direct method (DM) and the root mean square (RMS) method. Gear meshing is a main reason for gear vibration, so gear meshing power sensitivity to model parameters is analyzed in this paper. Also the influence of rotation speed is considered in the response sensitivity. The sensitivity characteristics make it possible to provide support for dynamic design optimization.
Localised Pre-Heating to Improve Inter-Layer Delamination Strength in Fused Deposition Modelling
Authors: Aitchison Andrew , Wang Qing 
Published: November 2019

Abstract
Additive manufacture, specifically Fused Deposition Modeling (FDM), is an advancing manufacture method opening up new possibilities in design previously impossible to machine, in a relatively affordable way. However, its use in functional products is limited due to anisotropic strength and reduced strength from injection molded components. This paper aims to increase the tensile strength of Acrylonitrile Butadiene Styrene (ABS) in the weakest direction (Z axis), where poor interlayer fusion and air gaps between extruded trails reduce strength. Extra thermal energy was applied to the top surface layer during the printing process (through hot air) to encourage more polymer chain diffusion across the boundary, and spreading out to fill air gaps. Multiple tensile test samples were printed at a variety of heat levels. The ultimate tensile strength σuts was plotted against these temperatures and a weak positive correlation was found. However, only air temperatures above 81°C increased strength past the control to a maximum of 1.4MPa. Heat application has proven to increase tensile strength, but needs to be applied with a more precise method, to the boundary interface, to allow greater thermal energy transfer without sacrificing print quality.
A Digital Twin-Driven Improved Design Approach of Drawing Bench for Brazing Material
Authors: Hu Bingtao , Feng Yixiong , Gao Yicong , Zheng Hao , Tan Jianrong 
Published: November 2019

Abstract
Brazing materials can be made into different shapes to meet the requirements of different scenarios and the welding rod is a very common form. The rough-processed welding rods must be properly finished by the drawing bench to remove the oxide film on the surface and made into a uniform diameter. However, the continuous welding rod often breaks resulting low production efficiency. To reduce the frequency of workers’ reconnection operation of broken welding rods, we proposed a digital twin-based approach to improve the design of the structure of the drawing bench. First, we established a full life cycle digital twin model for the welding rod from the formulation stage to the finishing stage. The product ontology of the welding rod was built and the key process parameters were collected. Second, based on the product ontology, the key structural parameter of the drawing bench that affects the internal stress of the welding rod was determined by means of analytic hierarchy process. Third, we modified the key structural parameter in the digital twin model and simulated the finishing process. A near-optimal parameter was found. Last, we improved the structure of the actual drawing bench accordingly and carried out some experiments. The results matched well with the simulation prediction and the frequency of welding rod breaking is significantly reduced, which proved the effectiveness of our proposed improved design approach.
Wave Dynamics in Reconfigurable Tristable Mechanical Metamaterials
Authors: Yasuda Hiromi , Korpas Lucia M. , Raney Jordan R. 
Published: November 2019

Abstract
We explore unique wave dynamics in a chain of tristable structures, inspired by multistable origami. We specifically focus on the frequency band structure of the chain, and conduct numerical and theoretical analysis. The band gap of the chain can be controlled by switching the stable state of each tristable structure. We also show that if two regions of the chain have different topological properties then wave localization can occur at the interface of the two regions. Interestingly, this interface mode is observed within the band gap. We demonstrate that the interface mode can be altered by leveraging the reconfigurable nature of the tristable structure. Our findings suggest a new strategy for controlling wave propagation in reconfigurable structures, which could be relevant for engineering applications such as energy harvesting.
Characterization of the Damping Coefficient in the Continuous Contact Model
Authors: Poursina Mohammad , Nikravesh Parviz E. 
Published: November 2019

Abstract
This article presents an analytical formula to characterize the damping coefficient in a continuous force model of the direct central impact. The contact force element consists of a linear damper which is in a parallel connection to a spring with Hertz force-deformation characteristic. Unlike the existing models in which the separation condition is assumed to be at the time at which both zero penetration (deformation) and zero force occur, in this study, zero contact force is considered as the separation condition. To ensure that the continuous contact model obtains the desired restitution, an optimization process is performed to find the damping coefficient. The numerical investigations show that the damping coefficient can be analytically expressed as a function of system’s parameters such as the effective mass, penetration speed just before the impact, Hertz spring constant, and the coefficient of restitution.