bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonlinear Responses of a Cantilever Honeycomb Sandwich Plate under Aerodynamic Pressure
Authors: Zhang Junhua , Qi Xiaohui 
Published: September 2019

Abstract
Honeycomb sandwich structures can be used on wings of airplane and the wings may be simplified to a cantilever plate. Airplanes will be affected by airflows inevitably during flight. In this paper, nonlinear vibrations of a cantilever honeycomb sandwich panel affected by aerodynamic force are investigated. The equations of the cantilever honeycomb sandwich panel under aerodynamic pressure and in-plane excitation are obtained by using Hamilton’s principle and the Galerkin method. The equations are nonlinear ordinary differential equations in lateral oscillations with two degree of freedom. Nonlinear dynamics of the cantilever honeycomb sandwich panel under aerodynamic force are derived which is based on third-order piston theory. The nonlinear dynamics of the cantilever honeycomb sandwich panel under aerodynamic force and in-plane excitation are given by numerical simulations. The results show that one can adjust the frequency of the in-plane force to achieve the purpose of vibration reduction in a certain range. In the presence of in-plane forces and aerodynamic interaction, the dynamic behavior of the plate appears in a new form of vibration-intermittent flutter.
Vibration suppression of cantilever plate using nonlinear energy sink
Authors: Liu G , Zhang W 
Published: September 2019

Abstract
Cantilever structure is widely used in the field of aerospace engineering. Due to the complex working environment and the excitation effect, the vibration suppression of the structure is extremely important. The Nonlinear Energy Sink (NES), which is characterized as light weight, targeted energy transfer and high damping efficiency, provides the demanding for the design of vibration suppression of aerospace structures. In this paper, the NES is used to study the vibration reduction of cantilever rectangular plates. Based on the Kirchhoff hypothesis, the coupling dynamic equations of the between the thin plate and the NES are established, and the response of the structure in the first order transverse bending is studied by modal truncation. The suppression effect of the NES under different parameters is analyzed which can provide some theoretical support for the cantilever structure in engineering application.
Ultra-fine high-carbon steel wire drawing with ultrasonic vibration
Authors: Cao Hengqiang , Shan Xiaobiao , Liu Shen , Shi Yongjun , Xie Tao 
Published: September 2019

Abstract
Ultra-fine high-carbon steel wires are widely used in the field of diamond wire saws. The traditional method for drawing ultra-fine high-carbon steel brings many drawbacks. This paper designed an ultrasonic transducer whose frequency is 28 kHz to overcome the above drawing problem of ultra-fine steel wire with a diameter 65 μm. Influences of the ultrasonic vibration on the drawing force and the diameter of wire cycle were investigated by experimental methods. The experimental results showed that the drawing force was reduced by up to 16.6% and the diameter of wire cycle was enlarged by up to 9.7%. Besides, the continuous drawing time of the ultra-fine wire was effectively prolonged. This study can contribute to enhancing the productivity of the ultra-fine wire processing in practical production.
Airflow energy harvesting through diamagnetically levitated magnet rotor
Authors: Gong Qi , Su Yufeng , Zhang Kun , Wu Kedi 
Published: September 2019

Abstract
An airflow energy harvester by using diamagnetic levitation technology to generate electricity is presented in this paper. The energy harvester consists of a lifting magnet, an upper pyrolytic graphite plate, a magnet rotor, two centrosymmetric nozzles, induction coils, and a lower pyrolytic graphite plate. The lifting magnet is used to exert an upward force on the magnet rotor, so the levitated magnet rotor can stably levitate. In order to study the output characteristics of the energy harvester, two streams of airflow are applied to the magnet rotor to form a force couple. The relationship between the induced voltage and the airflow rate was analyzed and tested by simulation and experiment. In this paper, the flow rate was controlled by the mass flow controller, and the output voltage under different airflow rates was recorded. It was found that the peak induced voltage of the coil could reach 2.8 V when the flowrate was 3000 sccm.
Flutter Control of a Two-dimensional Airfoil based on Adaptive Dynamic Programming
Authors: Jia Su , Sun Jian Qiao , Ding Qian 
Published: September 2019

Abstract
The severe aeroelastic vibrations can lead to structural damage and threaten the flight safety. It is an important topic to develop active controllers for aeroelastic stabilization and flutter suppression. The traditional control methods need the clearly established mathematic model, whereas establishing an accurate airfoil model with structural and aerodynamic nonlinearities is a difficult task. So a novel data-driven optimal design scheme, adaptive dynamic programming (ADP), is proposed in this paper for a nonlinear airfoil system with one trailing-edge control surface. The proposed ADP algorithm iteratively updates the control policy by using the state and input data without knowing the system dynamical model. Calculation shows that the control policy is convergent after several iterations. Finally, the superiority and feasibility of the control method are verified by simulation.
Experimental investigation of harvesting stochastic vibration energy by a piezoelectric inverted beam with pendulum
Authors: Pan J N , Qin W Y 
Published: September 2019

Abstract
We proposed a harvester composed of inverted piezoelectric beam and a pendulum to enhance the efficiency of vibration-based energy harvesting. Corresponding experiments were performed for validation. The amplitude-frequency response obtained in the vicinity of second natural frequency shows the feature of soften-spring type. The region of multiple solutions originated from nonlinearity could be extended when the excitation is increased to a high level. The experiment under stochastic excitation was carried out, and the corresponding responses were obtained. The absence of low frequency component in stochastic excitation was designed in excitation to show the first natural frequency component in response comes from the coupling between modes. The results verify the energy transformation phenomenon between the first two modes.
Dynamics analysis of multi-field coupled piezoelectric energy harvester under random excitation
Authors: Zhang Xuhui , Zuo Meng , Tan Houzhi , Wu Zhonghua , Lai Zhengpeng , Fan Hongwei 
Published: September 2019

Abstract
Automaatic fully mechanized mining face requires highly equipment condition monitoring. Complex environment of coalmine means the difficulty of wiring and power supply of wired monitoring. The multi-field coupled piezoelectric energy harvester (MPEH) could power wireless monitoring nodes by capture vibration energy from mining equipment. This paper makes a complete investigation of the distance effect of magnet, noise spectrum density and damping on the dynamic response characteristics of the MPEH under random excitation. Taking white Gaussian noise as input excitation, a dynamic model of the MPEH with random excitation in multiple fields is established. The probability density function of dynamic response under different system parameters is obtained by FPK equation, and the stationary mean square value and power spectral density function of system response are given by the ignored high order cumulant truncation method. In order to verify the accuracy of analytical results, the Monte Carlo numerical analysis is presented. Results show that the decrease of the magnetic distance will cause the moving of peak power spectrum frequency to low frequency. Reducing system damping ratio, narrowing magnetic distance or increasing excitation spectral density can enhance the probability of large period vibration and increase the average power of the system.
Nonlinear Dynamics and Performance Enhancement of Multi-stable Wideband Energy Harvesting: Theoretical Analysis
Authors: Wang C , Yang X , Lai S K 
Published: September 2019

Abstract
A new multi-stable wideband harvester is proposed to increase the power density of energy harvesting under wide-bandwidth and low-frequency operations. This harvester can possess with an arbitrary multi-stable state by combining the nonlinearities of stopper-engaged cantilevers and magnetic forces. The harvesting efficiency can be enhanced by interwell oscillations and the global amplitude of the harvester is restricted by the cantilever-stopper engagement. An electromechanical coupling model of the proposed harvester is established to describe its dynamic characteristics. To explore the influence of potential well configurations on a multi-stable energy harvesting, the proposed harvester with four typical potential well configurations is considered while its equivalent nonlinear restoring force can be experimentally identified. The dynamic characteristics of these four configurations at different levels of a harmonic excitation will be explored by both numerical and experimental methods. It is expected that a multiple-well potential with non-uniform depths and shallower outer wells is much more suitable for the proposed system when the external excitation exceeds a critical intensity.
Establishment of rubber thermo-viscoelastic constitutive model and analysis of temperature field
Authors: Chu Hongyan , Hong Yingjie , Chen Qi , Wang Rui 
Published: September 2019

Abstract
Rubber has strong nonlinear viscoelastic behavior. Under the periodically changing external forces, it show deformation hysteresis, mechanical loss and heat generation. In this work, a pair of extruding and rotating steel-rubber rollers was researched. Stress relaxation data at different temperatures were obtained through dynamic thermomechanical analysis experiments. A thermo-viscoelastic rubber constitutive model with temperature factor was obtained by combining the generalized Maxwell model where parameters of rubber viscoelastic were fitted with Prony series. Then, the temperature experiment of structure was conducted on the experimental platform. Based on thermo-viscoelastic constitutive model, simulation and analysis of temperature distribution of steel-rubber roller was obtained. The results of experimental data were consistent with simulation results. Further, the rubber constitutive models of pure elasticity, the superposition of elasticity and viscoelasticity with non-temperature factors, the superposition of elasticity and viscoelasticity with temperature factors were simulated respectively. The results show that the third model was more consistent with the actual experimental results, which verifies the accuracy of constitutive model building by this work. Through numerical comparison and analysis, it was proved that viscoelastic hysteretic heat generation is an indispensable source of heat generation in rubber structure movement.
Atomistic simulation of the nanoindentation behavior of graphene/Al multilayered nanocomposites
Authors: Zhu Jia-Qi , Liu Xia , Yang Qing-Sheng 
Published: September 2019

Abstract
In this paper, the mechanical behaviour of graphene/aluminum multilayered nanocomposites (GAMC) was studied by conducting the nanoindentation simulations using molecular dynamics (MD) method. The reinforcement effect of graphene on aluminum was investigated by two different cases: the graphene layers are considered as the reinforcement and the coating materials respectively. The microscopic deformation mechanism is investigated through the study of a hemispherical diamond indenter indenting against the monocrystalline Al and GAMC. For the graphene-coated Al composite (GCA), it is found that graphene coating layers have an effect on the characteristics of dislocation slip in Al matrix and improve the load carrying capacity of the GCA significantly. In addition, graphene-reinforced Al composite (GRA) with different spacing-distance of the graphene layers was investigated. It is concluded that the GRA shows an increasing nanoindentation properties with reducing the thickness of Al layers. Although the present research is based on monocrystalline aluminum, the deformation mechanism here can be applied to other face-centered-cubic (FCC) monocrystalline metals structures.
Anti-buckling design of cylindrical shells by local surface nanocrystallization
Authors: Xu X S , Zhao Z , Lim C W , Wang W , Lian Z B , Zhou Z H 
Published: September 2019

Abstract
A novel surface modification method, namely the surface nanocrystallization technology, is introduced to enhance the anti–buckling performance of the metal cylindrical shells under axial impact loading. The effects of local nanocrystallization layouts are explored by evaluating the critical buckling loads of four local nanocrystallization layouts including the local circumferential stripes (LCS), local axial stripes (LAS), spaced latticed blocks (SLB) and oblique latticed blocks (OLB). Numercial results show that, compared to the untreated cylindrical shells, the critical buckling loads of the local nanocrystallized ones are significantly improved by the local nanocrystallization treatment. The critical buckling loads for the LAS design is improved by 80%. It is concluded that the local nanocrystallization treatment is a very promising method to design and manufacture the metal cylindrical shells with high anti-buckling performance.
Effect of interference-fit percentage and preload on the mechanical behaviour of single-shear lap composite joint
Authors: Zou Peng , Cheng Hui 
Published: September 2019

Abstract
The mechanical behaviour of composite interference-fit structure is affected by both interference-fit percentage and bolt preload. These two factors combine and interact with each other, leading to a complex joint behaviour. In this paper, the effect of interference-fit percentage and bolt preload on load and damage of single-lap bolted joint is studied from both experiment and finite-element model (FEM). Firstly, an interference-fit preload applying experiment was made. Preloads on both nut and bolt head were measured for different percentages and torques, and the torque coefficient was calibrated. A scanning electron microscope (SEM) analysis on the experimental joint was also conducted to research damages around the hole. Then, the relationship between torque and multi-layer preloads and a composite preload FEM based on progressive damage mechanism were built. The multi-layer preloads were obtained and compared with the experimental measured ones, which verified the reliability of the FEM. In addition, the damage mechanism of different percentages and torques were also analysed and discussed with the simulation results.
Modeling of nonlinear dynamic characteristics and experimental study of piezoelectric energy harvesters with a panel type structure
Authors: Jia Jinda , Shan Xiaobiao , Liu Yingxiang , Xie Tao 
Published: September 2019

Abstract
Panel flutter vibration is a typical aeroelastic phenomenon taking place in flying aircrafts as they move at high speed. The vibration has been a hot academic research aspect. The present paper focuses on converting this aerodynamic mechanical vibration into useful electricity by using piezoelectric patches. A mathematical Euler-Bernoulli distributed model of the piezoelectric energy harvesting system is established to investigate nonlinear dynamical behaviour of a piezoelectric cantilever plate. The dynamical responding ability of energy harvesting is numerically calculated. Influences of the length and the thickness of piezoelectric layer, the external resistance and wind velocity on the output performance are emphatically explored. A series of prototypes of piezoelectric energy harvesters with different physical dimensions were designed and manufactured. Wind tunnel experiments were setup and carried out at different wind velocities. The experimental results show that the harvesting power gets enhanced as increasing the wind velocity. The maximum power could be obtained at condition of a reasonable piezoelectric length and width. Maximum power is 2.0 mW at wind speed of 11.0 m/s. This work provides a strong theoretical and experimental basis for the study of aerodynamic energy harvesting from panel aircrafts.
Design and simulation of a novel ancient Chinese bow-type piezoelectric actuator
Authors: Cao Limin , Ma Chicheng , Guo Zonghe , Ma Juncheng 
Published: September 2019

Abstract
Piezoelectric materials are increasingly researched and used because of their ability to convert electrical energy and mechanical energy. Piezoelectric patches are usually applied with other structures to form piezoelectric actuators to expand the capability and use of piezoelectric patches. In this paper, a new piezoelectric actuator based on the ancient Chinese arch structure is proposed. The piezoelectric actuator is mainly composed of a bow device and several piezoelectric plates. Firstly, the electromechanical coupling model of the cantilever beam structure is established based on the finite element method. The action characteristics of the bow-type piezoelectric actuator are studied. Then static analysis of the cantilever beam with the bow-type piezoelectric actuator is applied. The effect of the bow-type piezoelectric actuator on the cantilever beam under different parameters is analysed and compared, including actuation voltages, locations and physical dimensions of the bow-type structure. Especially, the thickness of the device and the span of the bow device are optimized to better capability. The simulation results show that the thickness and the span of the bow-type device in the bow-type piezoelectric actuator affect the action of the piezoelectric actuator on the cantilever beam remarkably. Additionally, the bow-type piezoelectric actuator is easy to install, simple to manufacture, and can be reused. The research in this paper will provide a reference for the active control or energy harvesting of structural vibration.
Modal analysis of the coupled vibration in an aero-turbine compressor blisk considering both aerodynamic and centrifugal load
Authors: Wang H B , Zhang W , Yao M H , Zhang M M 
Published: September 2019

Abstract
To lighten the aircraft engine and improve its propulsion efficiency, many aero engines adopt the blisk structure comprising both the rotor disk and blades. Since the disk becomes thinner, the stiffness of the structure decreased apparently, which causes the occurrence of large amplitude vibration in the blisk. This passage utilizes the finite element analysis (FEA) and computational fluid dynamics (CFD) simulation software to investigate the coupled vibration characteristics between the blades and the disk of the blisk with realistic geometric data, in which the aerodynamic load and centrifugal load are considered. At first, the CFD and finite element models of an aero-turbine compressor blisk are built. Then the pressure load data under some critical rotating speeds from CFD simulation are communicated to FEA software by data interpolating method, and the simulation of modal characteristics of the blisk is conducted in FEA. At last, the natural modal characteristics of the blisk structure are obtained, including the resonance speed Campbell diagram, the natural frequencies and corresponding mode shapes. According to the Campbell diagram, it indicates that the most critical mode is the fourth order mode. It is found that the mode shape of the fourth order in the blisk is the coupling of the disk torsional and blades first bending vibration. It is easy to lead to vibration failure when large amplitude vibration of the fourth mode occurs in the blisk. Also, it could also conclude that the modal characteristics of the coupled vibration in the rotating blisk are very sensitive to the disk stiffness. These results provide basic data for the further research in nonlinear vibration and structure optimization of the blisk, and also a simulating method to investigate coupled vibration between the blades and the disk of the blisk considering both aerodynamic and centrifugal load.
Multi-objective optimal sliding mode control design of active suspension system with MOPSO algorithm
Authors: Gao Kunming , Guo Zonghe , Qin Zhichang , Li Ruixian , Zhang Yuchen 
Published: September 2019

Abstract
In order to improve the ride comfort and driving stability of the vehicle, a design method of sliding mode controller based on multi-objective particle swarm optimization algorithm is proposed for the vehicle active suspension. Based on the model of 1/4 vehicle active suspension system, the sliding mode controller is designed by using sliding mode control method. The stability of the sliding mode surface is verified by using Lyapunov stability theory. The stability conditions of the sliding mode surface are obtained by combining Hurwitz stability criterion. The particle swarm optimization algorithm is used to optimize the multi-objective optimization of the active suspension and the numerical simulation is carried out. The results show that after multi-objective parameter optimization, the ride comfort and driving stability of the vehicle are significantly improved, which provides a theoretical basis for the research of the vehicle active suspension system.
Bifurcation and Chaos of Rotating Inextensional Ring
Authors: Wang Ligang , Wang Jiaoyang , Asokanthan S F 
Published: September 2019

Abstract
In this paper, the nonlinear dynamics of the inextensional ring structure is investigated. Based on the elasticity theory and the assumption of the inextension of ring, a dynamical model of the ring is established considering the elastic support, the external load and the damping. Then, according to the Galerkin method, the nonlinear mode functions of inextensional ring are used to obtain the order differential equations of ring. Finally, the numerical simulation is carried out and the nonlinear behavior, such as double-period bifurcation, quasi-periodic motion and chaos, is discussed. And the effect of the disturbance of the rotating velocity on the nonlinear behavior of ring is investigated.