Comparative Research on the Effects of the Self-Healing Microcapsules on the Modal Properties of Composite Brake

2010 ◽  
Vol 97-101 ◽  
pp. 1718-1725
Author(s):  
Li Zhang ◽  
Xiao Gang Ji ◽  
Yan Jue Gong
Keyword(s):  
Modal Analysis ◽  
Comparative Research ◽  
Damping Ratio ◽  
The Self ◽  
Modal Parameters ◽  
Disc Brake ◽  
Self Healing ◽  
Analysis Method ◽  
Element Analysis ◽  
Modal Properties

This paper makes comparative research on the effects of the self-healing microcapsules on the modal properties of composite disc brake pads. The two groups of composite brake samples are studied that the material of one brake sample is implanted by the microcapsules and the other sample has no microcapsule. Firstly, the computational modal analysis method based on finite element analysis software ANSYS is adopted to calculate the modal parameters of the samples, and the inherent vibration characteristics of the structures are obtained. Then the experimental modal analysis method with hammer is carried out to identify the experimental value of the modal parameters of the samples such as natural frequency and damping ratio. Finally, the theory analysis and experiment results from these two different methods are contrasted and analyzed. It indicates that the addition of the self-healing microcapsule improves the vibration reduction performance of the composite disc brake greatly.

scholarly journals Effect of Vinyl Flooring on the Modal Properties of a Steel Footbridge

2019 ◽  
Vol 9 (7) ◽  
pp. 1374 ◽  
Author(s):  
Javier Jiménez-Alonso ◽  
Jorge Pérez-Aracil ◽  
Alejandro Hernández Díaz ◽  
Andrés Sáez
Keyword(s):  
Modal Analysis ◽  
Operational Modal Analysis ◽  
Modal Parameters ◽  
Vibration Modes ◽  
Structural Elements ◽  
Average Increase ◽  
Analysis Method ◽  
Structural Element ◽  
Modal Properties

Damping ratios associated with non-structural elements play an important role in mitigating the pedestrian-induced vibrations of slender footbridges. In particular, this paper analyses the effect of vinyl flooring on the modal parameters of steel footbridges. Motivated by the unexpected high experimental damping ratios of the first vibration modes of a real footbridge, whose deck was covered by a vinyl flooring, this paper aims at assessing more accurately the experimental damping ratios generated by this non-structural element on steel footbridges. For this purpose, a laboratory footbridge was built and vinyl flooring was installed on it. Its numerical and experimental modal parameters without and with the vinyl flooring were determined. The operational modal analysis method was used to estimate experimentally the modal parameters of the structure. The damping ratios associated with the vinyl flooring were obtained via the substraction between the experimental damping ratios of the laboratory footbridge with and without the vinyl flooring. An average increase of the damping ratios of 2.069% was observed due to the vinyl flooring installed. According to this result, this type of pavement may be a useful tool to significantly increase the damping ratios of steel footbridges in order to reduce pedestrian-induced vibrations.

Modal Analysis of Self-Repairing Composite Gear Based on ANSYS

2011 ◽  
Vol 189-193 ◽  
pp. 2067-2070 ◽  
Author(s):  
Li Zhang ◽  
Xiao Yuan Bu ◽  
Yan Jue Gong
Keyword(s):  
Mechanical Properties ◽  
Finite Elements ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Modal Parameters ◽  
Self Healing ◽  
Analysis Method ◽  
Modulus Ratio ◽  
Finite Elements Analysis ◽  
Comparison Of Results

The mechanical properties of self-healing composite gear with microcapsules can be effectively improved. Based on Finite Elements Analysis method, the modal analysis of three different formulations of composites gear have been carried out in order to explore effects of self-healing microcapsule on the modal parameters of a gear. The comparison of results shows that modulus ratio is one of important inflencing factors on the natural frequency of a gear. The study in this paper provides a good foundation for further research on self-healing composite gear.

Experimental and FEM Modal Analysis of Workbench for PCB Drilling Machine

2010 ◽  
Vol 139-141 ◽  
pp. 2446-2451 ◽  
Author(s):  
Hong Qun Tang ◽  
Cheng Yong Wang ◽  
Bing Wang ◽  
Li Xin Huang ◽  
Shan Shan Hu ◽  
...  
Keyword(s):  
Modal Analysis ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Modal Parameters ◽  
Machining Parameters ◽  
Drilling Machine ◽  
Analysis Method ◽  
Measurement And Analysis ◽  
Overall Performance ◽  
Natural Characteristics

X-axis and Y-axis workbenches are important parts of PCB drilling machine. Theirs dynamic properties directly affect the overall performance of drilling machine. Modal analysis method was adopted in this paper. Measurement and analysis on vibration of X-axis and Y-axis workbenches based on LMS Test. Lab was carried out. The modal parameters such as natural frequency, damping ratio and corresponding vibration modes were obtained. The results present that the X-axis and Y-axis workbenches have a high fundamental frequency, which is 564Hz and 1014Hz respectively. And the damping ratio is less than 4.91% and 2.99%, which shows that the stiffness of the X-axis and Y-axis workbenches are higher. The FEM modal analysis shows that it has the similar results with the experiments in modal parameters. The analysis of natural characteristics of workbench provides guidance for optimizing machining parameters of drilling and improving structure of workbench.

scholarly journals Influence of Crack on Modal Parameters of Cantilever Beam Using Experimental Modal Analysis

2018 ◽  
Vol 1 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Siva Sankara Babu Chinka ◽  
Balakrishna Adavi ◽  
Srinivasa Rao Putti
Keyword(s):  
Numerical Analysis ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Cantilever Beam ◽  
Damping Ratio ◽  
Crack Depth ◽  
Experimental Modal Analysis ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Crack Location

In this paper, the dynamic behavior of a cantilever beam without and with crack is observed. An elastic Aluminum cantilever beams having surface crack at various crack positions are considered to analyze dynamically. Crack depth, crack length and crack location are the foremost parameters for describing the health condition of beam in terms of modal parameters such as natural frequency, mode shape and damping ratio. It is crucial to study the influence of crack depth and crack location on modal parameters of the beam for the decent performance and its safety. Crack or damage of structure causes a reduction in stiffness, an intrinsic reduction in resonant frequencies, variation of damping ratios and mode shapes. The broad examination of cantilever beam without crack and with crack has been done using Numerical analysis (Ansys18.0) and experimental modal analysis. To observe the exact higher modes of beam, discretize the beam into small elements. An experimental set up was established for cantilever beam having crack and it was excited by an impact hammer and finally the response was obtained using PCB accelerometer with the help sound and vibration toolkit of NI Lab-view. After obtaining the Frequency response functions (FRFs), the natural frequencies of beam are estimated using peak search method. The effectiveness of experimental modal analysis in terms of natural frequency is validated with numerical analysis results. This paper contains the study of free vibration analysis under the influence of crack at different points along the length of the beam.

scholarly journals A new modal analysis method applied to changing machine tool using clustering

2020 ◽  
Vol 12 (10) ◽  
pp. 168781402096832
Author(s):  
Xuchu Jiang ◽  
Xinyong Mao ◽  
Yingjie Chen ◽  
Caihua Hao
Keyword(s):  
Machine Tool ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Efficient Method ◽  
Machine Tools ◽  
Vibration Signal ◽  
Modal Parameters ◽  
Analysis Method ◽  
Modal Parameter ◽  
The Difference

The states of the machine tool, such as the components’ position and the spindle speed, play leading roles in the change of dynamic parameters. However, the traditional modal analysis method that modal parameters manually identified from vibration signal is greatly interfered by harmonics, and the process of eliminating interference is very inefficient and subjective. At present, there is a lack of a standard and efficient method to characterize modal parameter changes in different states of machine tools. This paper proposes a new machine tool modal classification analysis method based on clustering. The characteristics related to the modal parameters are extracted from the response signal in different states, and the clustering results are used to reflect the changes of machine tool modal parameters. After the amplitude of the frequency response function is normalized, the characteristics related to the natural frequency are acquired, and the clustering results further reflect the difference of the natural frequency of the signal. The new method based on clustering can be a standard and efficient method to characterize modal parameter changes in different states of machine tools.

The Comparative Modal Analysis of Simulation and Experiment on the Electronic Button-Sewing Machine Shell

2013 ◽  
Vol 668 ◽  
pp. 612-615
Author(s):  
Li Zhang ◽  
Guang Yuan Nie ◽  
Hong Wu ◽  
Jie Chen
Keyword(s):  
Comparative Analysis ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Mode Shape ◽  
Damping Ratio ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Ansys Software ◽  
Sewing Machine ◽  
Simulation And Experiment

In this paper, the simulation with ANSYS software and the experimental modal analysis by impacting are carried out on the electronic button-sewing machine shell. The modal parameters, such as the natural frequency, the damping ratio and the mode shape, are obtained. Comparative analysis of their results shows that the mode shapes of the machine shell are mainly the outward-expanding and inward-contracting vibrations, which provides a useful reference for vibration and noise reduction of the electronic button-sewing machine.

Analysis on Dynamic Characteristics of HTC100 NC Lathe Bed

2011 ◽  
Vol 328-330 ◽  
pp. 700-703
Author(s):  
Mo Wu Lu ◽  
Guo Ming Zhang ◽  
Wei Qiang Zhao
Keyword(s):  
Modal Analysis ◽  
Performance Indicators ◽  
Natural Frequencies ◽  
Dynamic Performance ◽  
Analysis Method ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
3D Solid ◽  
Modal Vibration ◽  
Ansys Workbench

The processing performance is closely related with dynamic performance and the dynamic performance is one of the most important performance indicators which is affecting the performance and product quality. The machine is affected most by the dynamic performance of machine bed. The modal analysis method is used to analyze the dynamic performance of the machine. In this paper, the modal analysis of lathe bed is conducted. A 3D solid model of HTC100 NC lathe bed is built with SolidWorks. In order to facilitate the finite element analysis, the model of lathe bed is simplified. The modal analysis of lathe bed is calculated with ANSYS Workbench 12. The first six natural frequencies and corresponding modes are obtained through modal analysis of the lathe bed. According to the low-order natural frequency and modal vibration shapes, the rigidity vulnerable area of lathe bed is realized, which provides the reliable theory to improve lathe bed structure.

Study on Acoustic System Designing of Two Dimensional Ultrasonic Polishing without Abrasives

2010 ◽  
Vol 455 ◽  
pp. 283-287
Author(s):  
Chuan Shao Liu ◽  
Jian Xin Zheng ◽  
Y.F. Liu
Keyword(s):  
Modal Analysis ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Response Analysis ◽  
Two Dimensional ◽  
Acoustic System ◽  
Analysis Method ◽  
Element Analysis ◽  
Harmonic Response Analysis ◽  
Aided Design

Acoustic system is the core component of power ultrasonic, which is designed by traditional analytic method and modal analysis with finite element analysis method. And component of the step-like horn with rectangular sections and tool head used in two dimension ultrasonic polishing without abrasives are studied, and the calculating results and modal analysis results are consistent on the whole. The harmonic response analysis for the component of horn and tool head is carried out and the three dimensional coordinates of the vibrating node on the tool head with maximal displacement are obtained. The fitting result shows that the moving trajectory of such node is ellipses, which meets the experimental requirement well. So a new way for designing acoustic system of two dimensional ultrasonic vibration through combining theoretical calculation with computer aided design may be applied.

The Operational Modal Analysis of an Industrial Sewing Machine

2013 ◽  
Vol 302 ◽  
pp. 541-545
Author(s):  
Li Zhang ◽  
Ya Jun Li ◽  
Yan Miao Ma
Keyword(s):  
Modal Analysis ◽  
Damping Ratio ◽  
Operational Modal Analysis ◽  
Structural Vibration ◽  
Modal Parameters ◽  
Vibration Source ◽  
Modal Shape ◽  
Modal Assurance Criterion ◽  
Low Frequencies ◽  
Sewing Machine

The operational modal analysis (OMA) was conducted on a certain industrial sewing machine to identify its modal parameters. Harmonic analysis was carried out through the OP.Synthesis method and false modes were removed according to the Modal Assurance Criterion, finally the natural frequency, damping ratio and modal shape were obtained. The vibration in the low frequencies is mainly nodding and shaking, while that in the high frequencies is local expansion of the head and motor end. The result shows that, the modal parameters of the industrial sewing machine can be well identified by the OMA method. This paper provides a valuable reference for the vibration source identification and structural vibration reduction.

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