scholarly journals Study on the Damping Effect of Particle Dampers considering Different Surface Properties

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Xiaowei Li ◽  
Yue Yang ◽  
Weixing Shi
Keyword(s):  
Energy Dissipation ◽  
Surface Property ◽  
Material Selection ◽  
Great Influence ◽  
Contact Theory ◽  
Theoretic Model ◽  
The Finite Element Method ◽  
Particle Damping ◽  
Vibration Experiment ◽  
Particle Dampers

Particle dampers are nonlinear vibration control devices. The surface property has a great influence on the performance of the particle damper, but it is difficult to be considered and analyzed. This paper firstly gives a view of how to establish a theoretic model of the particle damper. The dynamic equation and energy dissipation coefficient of collision are revised from the Hertz contact theory in the proposed theoretic model, considering the friction of particles. Then, a contrastive collision model relying on the finite element method is established to verify the reasonability of the theoretic model. The effects of different factors which will have an influence on the performance of the particle damper are discussed, and several conclusions on how to optimize the particle damper are proposed. Except for the aforementioned dynamic analysis, this paper also presents a particle damping index to evaluate the capability of energy dissipation of different materials, in order to facilitate the material selection in the practical design. Finally, an experiment is developed to verify the character of the collision and energy dissipation. The feasibility of the proposed method to estimate the surface property of different particles is validated by the free vibration experiment.

scholarly journals Damping prediction of particle dampers for structures under forced vibration using effective fields

2021 ◽  
Vol 23 (3) ◽  
Author(s):  
Niklas Meyer ◽  
Robert Seifried
Keyword(s):  
Energy Dissipation ◽  
Knowledge Exchange ◽  
Underlying Structure ◽  
Reduction Techniques ◽  
Linear Behavior ◽  
Damping Behavior ◽  
Effective Particle ◽  
Coupling Procedure ◽  
Particle Damping ◽  
Particle Dampers

AbstractParticle damping is a promising damping technique for a variety of technical applications. However, their non-linear behavior and multitude of influence parameters, hinder currently its wide practical use. So far, most researchers focus either on determining the energy dissipation inside the damper or on the overall damping behavior when coupled to a structure. Indeed, currently almost no knowledge exchange between both approaches occurs. Here, a bridge is build to combine both techniques for systems under forced vibrations by coupling the energy dissipation field and effective particle mass field of a particle damper with a reduced model of a vibrating structure. Thus, the overall damping of the structure is estimated very quickly. This combination of both techniques is essential for an overall efficient dimensioning process and also provides a deeper understanding of the dynamical processes. The accuracy of the proposed coupling method is demonstrated via a simple application example. Hereby, the energy dissipation and effective mass of the particle damper are analyzed for a large excitation range first using a shaker setup. The particle damper exhibits multiple areas of different efficiency. The underlying structure is modeled using FEM and modal reduction techniques. By coupling both parts it is shown that multiple eigenmodes of the structure are highly damped using the particle damper. The damping prediction using the developed coupling procedure is validated via experiments of the overall structure with particle damper.

Analysis and Optimal Placement of Particle Dampers Based on Discrete Element Simulation

2015 ◽  
Author(s):  
Shilong Li ◽  
Jiong Tang
Keyword(s):  
Energy Dissipation ◽  
Discrete Element ◽  
Optimal Placement ◽  
Time Simulation ◽  
Highly Nonlinear ◽  
Wide Range ◽  
Particle Damping ◽  
Long Time ◽  
Host Structure ◽  
Particle Dampers

Particle damper is formed by granular particles enclosed in a container which is attached to or embedded in a vibrating structure. The energy dissipation mechanism of a particle damper is highly nonlinear, and derived from a combination of collision/impact and friction among particles and between particles and the enclosure. Meanwhile, the coupling between particle dampers and the host structure and among multiple dampers further increases the difficulty to analyze the particle damping performance. In this paper, a new coupling method is developed to integrate the continuous host system with multiple particle dampers to analyze the energy transfer between the host structure and the dampers. The discrete element method (DEM) is employed to describe and analyze the particle motion inside each damper, which accurately accounts for various energy dissipation mechanisms of the particle damping system. In order to enhance the computational efficiency, a Verlet table combined with LC method is also used to improve the contact detection since the long time simulation is needed to perform damping analysis under a wide range of frequencies. The damping effect under different arrangements of particle dampers on a clamped-free beam is analyzed, and the results indicate that the optimal positions of dampers not only rely on the mode shape of the system, but also are dependent upon the excitation level.

Rolling Resistance Calculation Procedure Using the Finite Element Method

2019 ◽  
Vol 48 (3) ◽  
pp. 224-248
Author(s):  
Pablo N. Zitelli ◽  
Gabriel N. Curtosi ◽  
Jorge Kuster
Keyword(s):  
Finite Element ◽  
Energy Dissipation ◽  
Rolling Resistance ◽  
Element Model ◽  
The Finite Element Method ◽  
Temperature Changes ◽  
Rubber Compounds ◽  
Different Temperatures ◽  
Materials Used ◽  
Account Temperature

ABSTRACT Tire engineers are interested in predicting rolling resistance using tools such as numerical simulation and tests. When a car is driven along, its tires are subjected to repeated deformation, leading to energy dissipation as heat. Each point of a loaded tire is deformed as the tire completes a revolution. Most energy dissipation comes from the cyclic loading of the tire, which causes the rolling resistance in addition to the friction force in the contact patch between the tire and road. Rolling resistance mainly depends on the dissipation of viscoelastic energy of the rubber materials used to manufacture the tires. To obtain a good rolling resistance, the calculation method of the tire finite element model must take into account temperature changes. It is mandatory to calibrate all of the rubber compounds of the tire at different temperatures and strain frequencies. Linear viscoelasticity is used to model the materials properties and is found to be a suitable approach to tackle energy dissipation due to hysteresis for rolling resistance calculation.

scholarly journals The durability of flexible eddy current array (FECA) sensors in harsh service environments

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yujian Song ◽  
Tao Chen ◽  
Ronghong Cui ◽  
Yuting He ◽  
Xianghong Fan ◽  
...  
Keyword(s):  
Eddy Current ◽  
Fatigue Cracks ◽  
Radiation Environment ◽  
The Finite Element Method ◽  
Integrated Sensor ◽  
High Durability ◽  
Vibration Experiment ◽  
Service Environments ◽  
Salt Fog Corrosion ◽  
Salt Fog

AbstractSensors for structural health monitoring (SHM) need to be permanently integrated on structures and withstand the harsh service environments, which has been a big challenge for the application of SHM in aircrafts. This paper focuses on the durability of flexible eddy current array (FECA) sensors in harsh service environments of aircrafts, including vibration environment and several typical exposed environments. First, a kind of FECA sensor is illustrated and its integration method is proposed. Moreover, in order to study the durability of the sensor in vibration environment, the modal analysis is performed by the finite element method. According to the simulation results, the durability experiment in vibration environment is carried out under the fourth order vibration mode, which makes the sensor suffer the harshest vibration loads. During the vibration experiment, output signals of the sensor keep stable and the sensor is well bonded to the structure, which shows the integrated sensor has high durability in vibration environment. Finally, the durability of integrated sensors is separately tested in three exposed environments, including salt fog corrosion environment, fluid immersion environment, as well as hygrothermal and ultraviolet-radiation environment. After these environmental exposure experiments, all sensors are well bonded to structures and can effectively monitor fatigue cracks, which shows great durability. Therefore, FECA sensors can survive in harsh service environments of aircrafts, which provides important support for the engineering applications of FECA sensors.

Knowledge-Based System for Supporting the Design of a Plate-Press

2012 ◽  
Vol 12 (2) ◽  
Author(s):  
David Potočnik ◽  
Miran Ulbin ◽  
Bojan Dolšak
Keyword(s):  
Material Selection ◽  
Compressive Load ◽  
The Finite Element Method ◽  
Design Quality ◽  
Suitable Material ◽  
Improve Design ◽  
Knowledge Based System ◽  
Cad System ◽  
Design Time ◽  
Knowledge Based

This paper presents a knowledge-based system capable of giving the designer quality support when making decisions from the aspect of modeling the reinforcement of a plate-press within a position of maximum compressive load, and by choosing suitable material for the plate. Based on the selected combination of reinforcement and material, this system acquaints the user with the size and position of the largest comparative stress, and the greatest nodal displacement in the load-direction. This system operates based on the implemented knowledge of experts in the execution of design, material selection, and numerical analysis based on the finite-element method (FEM), which was written with the help of parameters within the knowledge-base of the CATIA V5 CAD-system. Using this system gives the user an opportunity to reach conclusions that are crucial for designing a plate-press or pressure-loaded die-elements, in general. The results reveal that the system can dramatically shorten design time and improve design quality in comparison to manual design process.

Coupling Simulation Algorithm of Dynamic Feature of a Plate With Particle Dampers Under Centrifugal Loads

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Zhaowang Xia ◽  
Xiandong Liu ◽  
Yingchun Shan
Keyword(s):  
Vibration Suppression ◽  
Extreme Temperature ◽  
Extreme Environment ◽  
Dynamic Feature ◽  
Simulation Algorithm ◽  
Centrifugal Forces ◽  
Granular Particle ◽  
Particle Damping ◽  
Particle Dampers ◽  
Element Method

Particle damper comprises granular particle enclosed in a container within a vibrating structure. The performance of particle damper is strongly nonlinear whose energy dissipation is derived from a combination of mechanisms including plastic collisions and friction between particles or particles and cavity walls. Particle damper containing suitable materials may be effective in a wider temperature range than most other types of passive damping devices. Therefore, it may be applied in extreme temperature environments where most conventional dampers would fail. It may also attenuate vibrations over a broad range of frequencies and cost less. Researches have indicated that particle damper could be a viable option for extreme environment applications. However, to date, no effort has come forward the can prove analytically or numerically that the particle damping is a viable solution for vibration suppression under centrifugal forces. In this paper, a coupling simulation algorithm based on the discrete element method and finite element method and the results of simulative studies aimed at understanding the effects of parameters of particle damper under centrifugal forces are presented. And the results show that the presented coupling simulation algorithm is effective and the analyses of dynamic feature of a plate with particle dampers under centrifugal loads are reasonable.

An innovative system of coupled steel plate shear wall with pin FUSE in link beam: Cyclic behavior and energy dissipation

2021 ◽  
pp. 136943322110542
Author(s):  
Mahdi Usefvand ◽  
Ahmad Maleki ◽  
Babak Alinejad
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Energy Dissipation ◽  
Steel Plate ◽  
Shear Walls ◽  
Shear Wall ◽  
High Ductility ◽  
The Finite Element Method ◽  
Steel Plate Shear Walls ◽  
Steel Plate Shear Wall

Coupled steel plate shear wall (C-SPSW) is one of the resisting systems with high ductility and energy absorption capacity. Energy dissipation in the C-SPSW system is accomplished by the bending and shear behavior of the link beams and SPSW. Energy dissipation and floor displacement control occur through link beams at low seismic levels, easily replaced after an earthquake. In this study, an innovative coupled steel plate shear wall with a yielding FUSE is presented. The system uses a high-ductility FUSE pin element instead of a link beam, which has good replaceability after the earthquake. In this study, four models of coupled steel plate shear walls were investigated with I-shaped link beam, I-shaped link beam with reduced beam section (RBS), box-link beam with RBS, and FUSE pin element under cyclic loading. The finite element method was used through ABAQUS software to develop the C-SPSW models. Two test specimens of coupled steel plate shear walls were validated to verify the finite element method results. Comparative results of the hysteresis curves obtained from the finite element analysis with the experimental curves indicated that the finite element model offered a good prediction of the hysteresis behavior of C-SPSW. It is demonstrated in this study that the FUSE pin can improve and increase the strength and energy dissipation of a C-SPSW system by 19% and 20%, respectively.

scholarly journals Energy dissipation prediction of particle dampers

2009 ◽  
Vol 319 (1-2) ◽  
pp. 91-118 ◽  
Author(s):  
C.X. Wong ◽  
M.C. Daniel ◽  
J.A. Rongong
Keyword(s):  
Energy Dissipation ◽  
Particle Dampers

Analysis of Contact Stress on Coating Based upon Hertz Theory

2012 ◽  
Vol 155-156 ◽  
pp. 133-137
Author(s):  
Li Ping Wang ◽  
Hao Dong Luo ◽  
Yan Mei Cui
Keyword(s):  
Finite Element Method ◽  
Coating Thickness ◽  
Contact Stresses ◽  
Contact Theory ◽  
Hard Coating ◽  
Thin Coating ◽  
The Finite Element Method ◽  
Hertz Contact ◽  
Hertz Theory ◽  
Mechanics Performance

It is necessary to study the mechanics performance of thin coating, which composite the prerequisite of coating’s application. The contact stresses are important factors for the design of hard coating/substrate because the failure of the hard coating is usually caused by these stresses. The finite element method is applied to simulate the stress of coating with contact load based on Hertz contact theory. The accuracy of model was initially tested in systems without a film. The contact stresses have been calculated based on various coating/substrate modulus ratios and the coating thickness. Results show that coating thickness changes from 1.5um to 3um, the effects of coating/substrate combination is perfect. The research has important guiding significance for the application of coating.

Analysis of assembly defects in the cam curved groove mechanism

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Weibin Lan ◽  
Shouwen Fan ◽  
Shuai Fan
Keyword(s):  
Dynamic Characteristics ◽  
Contact Point ◽  
Contact Theory ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Interference Fit ◽  
Content Type ◽  
Cam Mechanism ◽  
Contact Points ◽  
General Mathematical Model

Purpose This paper aims to propose an elementary approach toward the identification of assembly defects of a cam curved groove mechanism. Design/methodology/approach A numerical analysis method for identifying the assembly defects of the cam curved groove mechanism is proposed by resorting to Hertz contact theory. A general mathematical model is established to analyze the kinematic and dynamic characteristics with an interference fit between the main roller and cam curved groove, including the contact points of the external and internal ring. Findings The analysis method of the contact point characteristics of the cam curved groove mechanism is given in this paper, and the kinematic and dynamic characteristics of the main roller can be analyzed. The numerical examples presented in this paper are implemented in MATLAB, feasibility and validity of the above algorithm are verified by the finite element method. Originality/value Regarding the defects of the interference fit, the findings of this paper can serve as a reference for researchers in reducing the defects in the design process of the cam mechanism.

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