Hydraulic Driven Rotating Flexible Beam: Theoretical Modal Analysis and Proportional Servo Drive Parameter Influence

2003 ◽  
Author(s):  
Javier Freire ◽  
Esteve Codina ◽  
Munir Khamashta
Keyword(s):  
Theoretical Model ◽  
Modal Analysis ◽  
Dynamic Performance ◽  
Normal Modes ◽  
Flexible Beam ◽  
Servo Drive ◽  
Analysis Methodology ◽  
Model Predictions ◽  
Hydraulic Servo ◽  
Machine Elements

Understanding the behavior of system with flexible elements is increasingly important in modern day technology. Reducing the mass of machine elements leads to a remarkable improvement in dynamic performance. However, a loss of precision also occurs with such an increase in flexibility. In order to arrive at a better understanding of systems with flexible elements, we are investigating the particular behavior of a hydraulic servo driven rotating flexible beam with the aim of obtaining a methodology that could be applied to a real application. To investigate this behavior, a set of models has been developed. In this paper, a theoretical model, using classical modal analysis methodology, is presented. The flexible beam is modeled in a standard way and the hydraulic servo drive is modeled as a boundary condition. Only normal modes will be investigated. This approach allows considering the servo proportional constant and the cylinder mass. It will be show that the servo proportional constant has low influence in the system eigen frequencies. The theoretical model predictions are validated experimentally.

A Theoretical Model for Dynamic Performance Prediction of Air-Foam Flooding in Heterogeneous Reservoirs

2016 ◽  
Author(s):  
Jun Yang ◽  
Xiangzeng Wang ◽  
Shubao Wang ◽  
Ruimin Gao ◽  
Yizhong Zhang ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Performance Prediction ◽  
Dynamic Performance ◽  
Heterogeneous Reservoirs ◽  
Foam Flooding

Application of High Performance Electro-Hydraulic Synchronous Servo System on NC Broaching Machine

2013 ◽  
Vol 721 ◽  
pp. 497-500
Author(s):  
Guo Jin Chen ◽  
Jing Ni ◽  
Ting Ting Liu ◽  
Ming Xu
Keyword(s):  
High Performance ◽  
Control Process ◽  
Servo System ◽  
Numerical Control ◽  
Servo Drive ◽  
Loop Control ◽  
Performance Accuracy ◽  
Drive Control ◽  
Hydraulic Servo ◽  
Output Quantity

Aiming at the lower performance, accuracy and efficiency of the existing motion control process for the traditional broaching machine, the paper studies the high-performance dual-hydraulic synchronous servo drive control technology. The synchronous electro-hydraulic servo system forms the closed loop control by the detection and feedback of the output quantity. It eliminates and restrains largely the influence of the adverse factors to obtain the high-precision synchronous driving performance. The numerical control system based on the real-time error compensation and the intelligent control to the auxiliary machinery is developed. It is used for the CNC broaching machine to make the steady-state synchronous displacement error of the double cylinders be ≤ 0.5mm.

Nonlinear Modal Analysis and Energy Localization in a Bladed Disk Assembly

2008 ◽  
Author(s):  
F. Georgiades ◽  
M. Peeters ◽  
G. Kerschen ◽  
J. C. Golinval ◽  
M. Ruzzene
Keyword(s):  
Modal Analysis ◽  
Nonlinear Oscillations ◽  
Periodic Structures ◽  
Normal Modes ◽  
Nonlinear Normal Modes ◽  
Energy Localization ◽  
Bladed Disk ◽  
Bladed Disk Assembly ◽  
Nonlinear Modal Analysis ◽  
Nonlinear Normal

The objective of this study is to carry out modal analysis of nonlinear periodic structures using nonlinear normal modes (NNMs). The NNMs are computed numerically with a method developed in [18] that is using a combination of two techniques: a shooting procedure and a method for the continuation of periodic motion. The proposed methodology is applied to a simplified model of a perfectly cyclic bladed disk assembly with 30 sectors. The analysis shows that the considered model structure features NNMs characterized by strong energy localization in a few sectors. This feature has no linear counterpart, and its occurrence is associated with the frequency-energy dependence of nonlinear oscillations.

DYNAMIC RESPONSE EVALUATION OF A FRAMED TYPE TURBO-GENERATOR FOUNDATION INCORPORATING DYNAMIC MODULUS AND OPERATING SPEED VARIATIONS

2004 ◽  
Vol 04 (03) ◽  
pp. 379-402 ◽  
Author(s):  
N. LAKSHMANAN ◽  
K. MUTHUMANI ◽  
N. GOPALAKRISHNAN ◽  
K. SATHISH KUMAR
Keyword(s):  
Dynamic Response ◽  
Dynamic Modulus ◽  
Dynamic Performance ◽  
Normal Operation ◽  
Synthesis Process ◽  
Operating Speed ◽  
Turbine Generators ◽  
Analysis Methodology ◽  
Modal Synthesis ◽  
Turbo Generator

Framed type foundation structures supporting turbo-generator machinery in a power plant have stringent vibration limits to ensure proper functioning of turbine generators without any breakdown. Current dynamic analysis methodology for such dynamically sensitive structures involves modal synthesis considering a single value of operating speed for the machinery and a uniform dynamic modulus for the frame material, which cannot be realized in site conditions. Such variations in the dynamic modulus across the whole structure and running speed of the machinery during normal operation have a profound impact on its dynamic performance which may result in alarmingly increasing amplitudes leading to subsequent breakdown of the machinery. A new methodology is outlined that combines the effects of the two variations by way of considering an enhanced range of speeds on either side of the operating speed for the modal synthesis process. This study shows the effects of variations in the dynamic modulus and operating speed on the peak dynamic response of a typical framed turbo-generator foundation structure. The modal synthesis process adopted in the study includes the significant modes in the sub-resonant range and a band of modes around the operating speed to obtain the peak response of the framed structure.

scholarly journals Effect of Processing Parameters on the Dynamic Characteristic of Material Extrusion Additive Manufacturing Plates

2019 ◽  
Vol 9 (24) ◽  
pp. 5345
Author(s):  
Shijie Jiang ◽  
Yinfang Shi ◽  
Yannick Siyajeu ◽  
Ming Zhan ◽  
Chunyu Zhao ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Theoretical Model ◽  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Experimental Tests ◽  
Processing Parameters ◽  
Combination Method ◽  
Mode Shapes ◽  
Material Extrusion ◽  
Function Combination

Material extrusion (ME), an additive manufacturing technique, can fabricate parts almost without geometrical limitations. With the growing application of ME parts, especially in actual working conditions, the dynamic characteristics are needed to be studied to accurately determine their reliability. This study provides an experimental validation of the theoretical model for predicting the dynamic characteristics of ME plates fabricated with three different key processing parameters, i.e., extrusion width, layer height and build direction. The model is set up based on the bidirectional beam function combination method, and a series of experimental tests are performed. It is found that different processing parameters result in the material properties of the samples to vary, thus leading to different dynamic characteristics. Through the comparison between predictions and measurements, it is shown that the influencing trend of the processing parameters is predicted precisely. The theoretical model gives reliable predictions in dynamic characteristics of ME plates. The natural frequency discrepancy is below 13.4%, and the predicted mode shapes are the same as the measured ones. This present work provides theoretical basis and technical support for further research in improving the dynamic performance of ME products, and helps extend the applications of this technique.

Operational modal analysis of a nonlinear oscillation system under a harmonic excitation

2020 ◽  
pp. 095440622097755
Author(s):  
Xuchu Jiang ◽  
Feng Jiang ◽  
Biao Zhang
Keyword(s):  
Modal Analysis ◽  
Nonlinear Oscillation ◽  
Normal Modes ◽  
Nonlinear Normal Modes ◽  
Harmonic Excitation ◽  
Forced Response ◽  
Operational Modal Analysis ◽  
Single Frequency ◽  
Modal Parameters ◽  
Oscillation System

Operational modal analysis (OMA) is a procedure that allows the modal parameters of a structure to be extracted from the measured response to an unknown excitation generated during operation. Nonlinearity is inevitably and frequently encountered in OMA. The problem: The traditional OMA method based on linear modal theory cannot be applied to a nonlinear oscillation system. The solution: This paper aims to propose a nonlinear OMA method for nonlinear oscillation systems. The new OMA method is based on the following: (1) a self-excitation phenomenon is caused by nonlinear components; (2) the nonlinear normal modes (NNMs) of the system appear under a single-frequency harmonic excitation; and (3) using forced response data, the symbolic regression method (SR) can be used to automatically search for the NNMs of the system, whose modal parameters are implicit in the expression structure expressing each NNM. The simulation result of a three-degree-of-freedom (3-DOF) nonlinear system verifies the correctness of the proposed OMA method. Then, a disc-rod rotor model is considered, and the proposed OMA method’s capability is further evaluated.

Optimization of the Dynamic Performance of the Direct Drive Volume Control System Based on Orthogonal Experiment

2014 ◽  
Vol 945-949 ◽  
pp. 2680-2684
Author(s):  
Ai Qin Huang ◽  
Yong Wang
Keyword(s):  
Control System ◽  
Dynamic Response ◽  
Orthogonal Experiment ◽  
Dynamic Performance ◽  
Servo System ◽  
Volume Control ◽  
Structure Parameters ◽  
Direct Drive ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

Direct drive volume control (DDVC) electro-hydraulic servo system has many advantages compared to the valve control system. However, its application scopes were restricted by its poor dynamic performance. To study the reason for the low dynamic response, mechanical model of DDVC electro-hydraulic servo system is established. Structure parameters influencing the dynamic performance are analyzed. To optimize the structure parameters, the methodology of orthogonal experiment is presented. The selection of factors and levels of the experiment and the choice of the evaluation index are also revealed. The proposed methodology is carried out by simulation software and an optimal configuration is obtained. The dynamic response of the DDVC system with the optimal parameters is simulated. The results show that the dynamic performances are improved. The cross-over frequencyincreases from 0.0046 rad/s to 0.0442 rad/s, and the rise time Tr decreases from 488.6s to 47.90s.

The Optimization of the PID Controller Using the Least Squares Method and the Improved Lbest PSO Algorithm

2013 ◽  
Vol 397-400 ◽  
pp. 1296-1303 ◽  
Author(s):  
Chuan Gui Yang ◽  
Zhao Jun Yang ◽  
Fei Chen ◽  
Yan Zhu ◽  
Ying Nan Kan ◽  
...  
Keyword(s):  
Least Squares ◽  
Pid Controller ◽  
Least Squares Method ◽  
Dynamic Performance ◽  
Pso Algorithm ◽  
Pid Tuning ◽  
Loading System ◽  
Hydraulic Servo ◽  
Tuning Scheme ◽  
Better Than

A self-adaptive PID tuning scheme is presented for the electro-hydraulic servo loading system. It requires the least squares method to identify the parameters of the transfer function of the electro-hydraulic servo loading system and utilizes the improved lbest PSO algorithm to optimize the PID controller. The scheme can provide the optimal PID parameters so that the dynamic performance and stability of the electro-hydraulic servo loading system are improved. Results show the fact that the dynamic performance and stability of the system are improved by the scheme. And in terms of optimization of PID controller, the improved lbest PSO algorithm is better than the lbest PSO algorithm and Ziegler-Nichols method.

Study on Material-Cutting with Electro-Hydraulic Servo Synchronization Control System for Large Band Saw Equipment

2013 ◽  
Vol 675 ◽  
pp. 86-90
Author(s):  
Guo Jin Chen ◽  
Jing Ni ◽  
Tin Tin Liu ◽  
Hui Peng Chen ◽  
Ming Xu
Keyword(s):  
Control System ◽  
Force Feedback ◽  
Synchronization Control ◽  
Servo Drive ◽  
Nc System ◽  
Hydraulic Cylinders ◽  
Hydraulic Servo ◽  
Control Technologies ◽  
Band Saw ◽  
Movement Synchronization

Aiming at the cutting for various kinds of material, in order to solve the problems that the present large band saw equipment at home is poor in the synchronization of the sawing feed and is lack of the dedicated NC system, the paper introduces the electro-hydraulic servo drive and digital control technologies, researches the synchronous servo drive and cutting force feedback control technologies, and develops the sawing machine’s control system based on the above technologies. The NC system has been applied in the CNC band saw equipment of the large Portal style. The saw frame uses the structure driven synchronously by the dual hydraulic cylinders in order to guarantee the accuracy of the feed motion. The control system driven by the electro-hydraulic servo synchronization detects the implementation of a two cylinders and does the displacement feedback to achieve the movement synchronization on both ends of the portal frame using the synchronous control strategy. That ensures the movement accuracy for the CNC band saw equipment of the large Portal style and improves the cutting accuracy and efficiency of the equipment.

Variable speed digital hydraulic transformer–based servo drive

2019 ◽  
Vol 234 (3) ◽  
pp. 287-298
Author(s):  
Matti Linjama
Keyword(s):  
Power Management ◽  
Management System ◽  
Peak Power ◽  
Average Power ◽  
Variable Speed ◽  
Servo Drive ◽  
Hydraulic Power ◽  
Hydraulic Servo ◽  
Power Management System ◽  
Hydraulic Accumulator

This article studies a digital hydraulic servo drive driven by a variable speed electric servomotor. Digital displacement control is implemented by using a two-port digital hydraulic power management system having six pistons and 18 on/off control valves. The first port of the digital hydraulic power management system controls the cylinder speed, while the second port is connected to a hydraulic accumulator. The peak power is taken from the accumulator, and the electric servomotor supplies only the average power into the system. An experimentally validated simulation model is used, and the results show a combination of adequate controllability and excellent energy efficiency. The estimated reduction in the size of the electric motor is 57%.

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