检索结果-南通市图书馆

Modeling and Simulation of a Cracked Beam with Different Location Using FEM

Computational Water, Energy, and Environmental Engineering 2020年第4期9卷 145-158页

作者： Rajib Karmaker Ujjwal Kumar Deb Amrita Das Department of Mathematics Premier University Chattogram Bangladesh Department of Mathematics Chittagong University of Engineering and Technology Chattogram Bangladesh Department of Civil Engineering Southern University Bangladesh Chattogram Bangladesh

Nowadays presence of crack in different engineering structures becomes a serious threat to the performance. Since most of the civil and mechanical structures may be damaged due to material fatigue, mechanical vibration, environmental attack and long-term service. Moreover, dynamical systems of a beam usually possess a non-linear character, which causes practical difficulties on the model-based damage detection techniques. This paper presents a novel approach to detect damage in a simply supported beam. In this study, a numerical simulation using the Finite Element Method (FEM) has been done to determine the frequencies to detect the crack in a concrete beam of length 0.12 m and width 0.015 m. A vibration-based model is employed to simulate the results by using COMSOL Multiphysics. At the tip, by performing the computational analysis it is found that the presence of cracks affects the natural frequencies of the concrete structure. It is observed that after applying load, the frequencies of the cracked beam have been changed with the variation of the location of the crack for all the modes of vibration. It also found that maximum frequency reserved at the cracked point so it will also help us to detect different hidden defects in any structure. A comparison is also made with the experimental results. It is also found that the effect of crack is more near the fixed end than at the free end.

关键词： vibration characteristics Crack Detection Modal Analysis Condition Monitoring FEM

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research on suspension parameters matching of front suspension tractor based on MATLAB

Research on suspension parameters matching of front suspensi...

引用

2007年中国农业工程学会学术年会

作者：吕宝占南京农业大学工学院

＜正＞For increasing speed and riding comfort being paid more attention,the study on vibrati on characteristics of off-road vehicles especially the vehicle without suspension,such as some agricu Itural and construction vehicles,is becoming an important *** a type of tractor made in Chi na as an example,the analysis of 2DOF twin-shaft vehicle dynamic model of vehicle without suspen sion and its natural frequencies were *** model was discussed by MATLAB/SIMULI NK,and the vibration characteristics of which were studied,such as plumb acceleration of vehicle b odypitch vibration angle acceleration and *** rationality of model was validated throu gh riding experiment under the condition oftrigonal road *** on these theories,the 3D OF twin-shall vehicle dynamic model of tractor with front suspension was built *** model with t he white-noise for random excitation was also researched by MATLAB/*** relationshi p of vibration characteristics of the vehicle and parameters of front suspension was put forward,thro ugh adjusting the parameters of stiffness and damping during *** conclusions can be p ut forward from the range of stiffness and damping in simulation: （1）The influence of suspension parameters to plumb vibration of vehicle body:the mean square root of plumb acceleration of vehicle body is reduced with increasing damping or reducing stiffness of front suspension. （2）The influence of suspension parameters to pitch vibration:the mean square root of pitch vib ration angle acceleration is increased with increasing stiffness,while the mean square roots of pitch vibration angle displacement of vehicle body and dynamic deflection of front suspension are reduced with increasing *** can be found that the smaller front suspension damping,the more promi nent influence of suspension stiffness to above parameters. （3）The influence of suspension parameters to dynamic deflection of front suspension and dyna

关键词： vehicle engineering vehicle with front suspension vibration characteristics simulation

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

ANALYSIS AND OPTIMIZATION OF A PIEZOELETRIC ACTUATOR COMBINED THE LONGITUDINAL vibration TRANSDUCER WITH THE TRAVELLING WAVE RING

ANALYSIS AND OPTIMIZATION OF A PIEZOELETRIC ACTUATOR COMBINE...

引用

2016年全国压电和声波理论及器件应用研讨会

作者： Long-cheng LI Sheng-qiang ZHOU State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics

Background, Motivation and Objective A piezoelectric actuator combined the longitudinal vibration transducer with the travelling wave ring was been proposed. The relationship of the pre-tightening force to transducer vibration characteristics was found. According to the three characteristics of work mode shape, the work modes of piezoelectric actuator were identified from the modes acquired by ADPL programming. And the structural parameter optimization design of the actuator was studied under ANSYS environment. Finally, a prototype was fabricated on the basis of the optimization design scheme. The experimental result of the prototype was consistent with the simulation analysis. Statement of Contribution/Methods This work is meaningful for several reasons. The pre-tightening force of bolt has an effect on vibration characteristics of the transducer. Especially, the amplitude is influenced obviously. The new modal identification method can identify the working modes from a series of modes. The interference modes are far away from the working modes of the actuator fabricated on the basis of the optimization design scheme. Results As a result, the frequency and amplitude of working mode to transducers changed under different pre-tightening force. The optimal value of assembling pre-tightening force to transducer was 7 Nm. The optimal value of structural parameters(P1, P2, P3, P5) were 3.15 mm, 2.2 mm, 0.57 mm, 34.9 mm respectively. On the basis of the optimization design, the smaller among absolute value of difference between working mode and interference mode(Δ f) was 1888 Hz. The radial amplitude was 0.26μm, the circumferential amplitude was 1.56μm, and the amplitude of Z axis was 2.85μm. Discussion and Conclusions A prototype was fabricated and tested. Two modes of the stator were investigated by a Laser Doppler Vibrometer PSV-300F-B(Polytec). The frequency difference of two modes was both over 1.5 k Hz. The experimental results were consistent with the simulation an

关键词： Pre-tightening force vibration characteristics Modal identification Optimization design

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

STUDY ON THE EXCITING METHOD FOR PIEZOELECTRIC ACTUATOR USING BENDING HYBRID MODES

STUDY ON THE EXCITING METHOD FOR PIEZOELECTRIC ACTUATOR USIN...

引用

2015全国压电和声波理论及器件技术研讨会

作者： Ding-wen WANG Ying-xiang LIU Wei-shan CHEN Jun-kao LIU State Key Laboratory of Robotics and System Harbin Institute of Technology

A new bending-hybrid-modes piezoelectric actuator was designed,and *** two operating principles using the whole piece of PZT ceramic plates were discussed,and compared with the traditional operating principle using the half piece of PZT *** effects of the no polarization part on the bending resonance frequencies were studied by modal ***,harmonic analysis was developed to obtain the electromechanical coupling *** effect of the size of no polarization part on the electromechanical coupling factor was *** last,the vibration trajectories of the two tip ends were investigated by transient *** two tip ends generated elliptical movements when the two bending vibrations were *** study gives detail discussion about the exciting methods for bending vibration of a boltclamped *** analysis results can guide the design of the piezoelectric actuator using bending hybrid modes.

关键词： Piezoelectric actuator Bending vibration No polarization part vibration characteristics

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

STUDY ON A NEW LINEAR ULTRASONIC MOTOR WITH BENDING PZT ELEMENTS

STUDY ON A NEW LINEAR ULTRASONIC MOTOR WITH BENDING PZT ELEM...

引用

2012全国压电和声波理论及器件技术研讨会

作者： Xiao-hui YANG Wei-shan CHEN Ying-xiang LIU Jun-kao LIU State Key Laboratory of Robotics and System Harbin Institute of Technology

A new linear ultrasonic motor using the 1st longitudinal and the 4th bending vibration modes of a bolt-clamped type transducer has been proposed and *** new motor with two feet employed only the bending PZT *** groups of PZT elements are clamped between the two exponential shape horns and the flange *** driving feet are located in the same side of the *** working principle of the proposed motor are *** the fabrication of a prototype,its admittance characteristics are measured using an impedance analyzer and the vibration modes are tested by a scanning laser Doppler ***,the mechanical ability of the prototype is tested.

关键词： Ultrasonic motor Bending PZT elements Admittance vibration characteristics

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：