Dynamic Characteristics Analysis for the Headstock of a Vertical Machining Center

2016 ◽  
Vol 836-837 ◽  
pp. 348-358
Author(s):  
Zhe Li ◽  
Song Zhang ◽  
Yan Chen ◽  
Peng Wang ◽  
Ai Rong Zhang
Keyword(s):  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Numerical Control ◽  
Vibration Test ◽  
Machining Accuracy ◽  
Modal Test ◽  
Machining Center ◽  
Characteristics Analysis ◽  
Nc Machine

Dynamic characteristics of numerical control (NC) machine tools, such as natural frequency and vibration property, directly affect machining efficiency and finished surface quality. In general, low-order natural frequencies of critical components have significant influences on machine tool’s performances. The headstock is the most important component of the machine tool. The reliability, cutting stability, and machining accuracy of a machining center largely depend on the structure and dynamic characteristics of the headstock. First, in order to obtain the natural frequencies and vibration characteristics of the headstock of a vertical machining center, modal test and vibration test in free running and cutting conditions were carried out by means of the dynamic signal collection and analysis system. According to the modal test, the first six natural frequencies of the headstock were obtained, which can not only guide the working speed, but also act as the reference of structural optimization aiming at frequency-shift. Secondly, by means of the vibration test, the vibration characteristics of the headstock were obtained and the main vibration sources were found out. Finally the corresponding vibration reduction plans were proposed in this paper. That provides the reference for improving the performance of the overall unit.

Vibration Characteristics Analysis of an Aero-Engine Turbine Blade

2012 ◽  
Vol 487 ◽  
pp. 894-897
Author(s):  
Wei Qiang Zhao ◽  
Yong Xian Liu ◽  
Mo Wu Lu ◽  
Qing Jun Guo
Keyword(s):  
Optimal Design ◽  
Turbine Blade ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Vibration Characteristic ◽  
Analysis Method ◽  
Aero Engine ◽  
Characteristics Analysis

This paper introduces the FEA method for a certain type of aero-engine turbine blade and makes a vibration characteristics analysis to this aero-engine turbine blade based on this method. The vibration characteristic of this aero-engine turbine blade is studied and the natural modal of the turbine blade is calculated based on UG software. The first six natural frequencies and mode shapes are given. According to the analysis results the dynamic characteristics of the blade are discussed. The analysis method and results in this paper can be used for further study on optimal design and vibration safety verification for the blade.

FEA on Vibration Characteristics of a Shrouded Turbine Blade

2012 ◽  
Vol 189 ◽  
pp. 443-447
Author(s):  
Wei Qiang Zhao ◽  
Yong Xian Liu ◽  
Mo Wu Lu
Keyword(s):  
Optimal Design ◽  
Modal Analysis ◽  
Turbine Blade ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Software Environment ◽  
Aero Engine ◽  
Characteristics Analysis

This paper introduces a FEA method for vibration characteristics analysis of an aero-engine shrouded turbine blade and makes an actual modal analysis of this shrouded blade based on this method in UG software environment. The first six natural frequencies and mode shapes of this shrouded blade are calculated. And also, the dynamic characteristics of the shrouded turbine blade are discussed in detail according to the analysis results. The FEA method and the vibration characteristics analysis results in the paper can be used for optimal design and vibration safety verification of this aero-engine shrouded turbine blade.

scholarly journals Study of the Dynamic Characteristics of Ball Screw with a Load Disturbance

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Zhe Du ◽  
Xiao-Lan Zhang ◽  
Tao Tao
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristics ◽  
Numerical Control ◽  
Hertzian Contact ◽  
Ball Screw ◽  
Machining Accuracy ◽  
Contact Deformation ◽  
Nc Machine Tool ◽  
Load Disturbance ◽  
Nc Machine

The dynamic character of ball screw is the key factor that influences the machining accuracy of numerical control (NC) machine tool. To improve the dynamic characteristics of the NC machine tool, it is necessary to study the dynamic characteristics of a ball screw. In this paper, the kinematics of a ball screw mechanism (BSM) are studied to expound the dynamic process of the drive, and the load disturbance is considered to analyze the contact deformation based on the Hertzian contact theory. The velocity relationships among the ball, screw, and nut are analyzed, and the influence of the contact deformation on the dynamic characteristics is simulated and investigated experimentally. The results show that the relationships between the contact deformation, which is affected by the material characteristics, the contact angle, and the load of nut are nonlinear. The contact deformation is a factor that cannot be ignored when considering the dynamic machining error of high-speed and high-precision machine tools.

Error correction technique for numerical control machine tools based on the simplex method

2021 ◽  
pp. 095440542110281
Author(s):  
Hongwei Liu ◽  
Rui Yang ◽  
Pingjiang Wang ◽  
Jihong Chen ◽  
Hua Xiang
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Simplex Method ◽  
Tool Path ◽  
Repeated Measurements ◽  
Numerical Control ◽  
Machining Accuracy ◽  
Correction Technique ◽  
Fluctuation Range ◽  
Nc Machine

The objective of this research is to develop a novel correction mechanism to reduce the fluctuation range of tools in numerical control (NC) machining. Error compensation is an effective method to improve the machining accuracy of a machine tool. If the difference between two adjacent compensation data is too large, the fluctuation range of the tool will increase, which will seriously affect the surface quality of the machined parts in mechanical machining. The methodology used in compensation data processing is a simplex method of linear programming. This method reduces the fluctuation range of the tool and optimizes the tool path. The important aspect of software error compensation is to modify the initial compensation data by using an iterative method, and then the corrected tool path data are converted into actual compensated NC codes by using a postprocessor, which is implemented on the compensation module to ensure a smooth running path of the tool. The generated, calibrated, and amended NC codes were immediately fed to the machine tool controller. This technique was verified by using repeated measurements. The results of the experiments demonstrate efficient compensation and significant improvement in the machining accuracy of the NC machine tool.

Static and Dynamic Characteristics Analysis of HTM125 Milling Complex Machining Center Column

2014 ◽  
Vol 1077 ◽  
pp. 191-196
Author(s):  
Yu Hou Wu ◽  
Yu Hang Ren ◽  
De Hong Zhao ◽  
Feng Lu
Keyword(s):  
Dynamic Characteristics ◽  
Three Dimensional ◽  
Mode Shapes ◽  
Three Dimensional Model ◽  
Static And Dynamic Characteristics ◽  
Machining Center ◽  
Characteristics Analysis ◽  
Object Of Study ◽  
Five Axis ◽  
Dynamic Characteristics Analysis

The column of heavy double turret five-axis horizontal milling complex machining center is taken as the object of study. Solidworks is used to establish three-dimensional model of milling machining center column, the established modal is be imported into ANSYS Workbench for static and dynamic characteristics analysis. First, by comparing the column deformation, the stress and strain under no-load and load conditions, which is concluded that column design is too conservative and be optimized. Secondly, the modal analysis was carried out on the column, which provides a theoretical basis for the optimization of the column by getting the first six natural frequencies and mode shapes of cloud.

Dynamic Characteristic Analysis of CNC Turret Punch Servo Beam

2016 ◽  
Vol 836-837 ◽  
pp. 522-528
Author(s):  
Yan Jun Guo
Keyword(s):  
Dynamic Characteristics ◽  
Optimization Design ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Characteristic Analysis ◽  
Boundary Constraints ◽  
Modeling Methodology ◽  
Characteristics Analysis ◽  
Dynamic Characteristics Analysis

This paper resolved CNC turret punch cause vibration phenomenon in the course of processing sheet,analysis of its dynamic characteristics of the beam servo feed mechanism, using the method of constrained modal analysis.Through the establishment of finite element model exactly for the servo beam and setting the boundary elastic restraint stiffness, solving the natural frequencies and mode shapes of the servo beam under boundary constraints and loading conditions. Constraints modal analysis results are consistent with experimental monitoring results of CNC turret punch servo beam. This modeling methodology and results of the analysis has a high practical value for CNC turret punch dynamic characteristics analysis and structural optimization design.

Thermal Error Compensation on Boring & Milling Machining Center Feed System Based on PMAC

2014 ◽  
Vol 945-949 ◽  
pp. 1669-1672
Author(s):  
Jun Sun ◽  
Xing Liu ◽  
Zhi Xuan Li
Keyword(s):  
Real Time ◽  
Error Compensation ◽  
Tool Path ◽  
Thermal Error ◽  
Machining Accuracy ◽  
Feed System ◽  
Nc Machine Tool ◽  
Machining Center ◽  
Nc Machine ◽  
Processing Accuracy

Aiming to deal with thermal error of NC machine tool which can cause reduce of machining accuracy, this paper uses an external error compensation which interacts with NC controllers and PMAC multi-axis and then revises the tool path by adding the error tested in real-time by PMAC card. The processing accuracy is improved eventually. This method can compensate machine geometric errors and thermal errors in real-time. Comparing with other methods of error preventing, this method is more effective and affordable.

FEA on Vibration Characteristics of a Gas Turbine Blade-Disc

2012 ◽  
Vol 516-517 ◽  
pp. 731-734 ◽  
Author(s):  
Wei Qiang Zhao ◽  
Yong Xian Liu ◽  
Mo Wu Lu
Keyword(s):  
Optimal Design ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Natural Mode ◽  
Analysis Method ◽  
Gas Turbine Blade ◽  
Natural Modes ◽  
Characteristics Analysis

This paper introduces a FEA method for vibration characteristics analysis of blade-disc structure and makes a modal analysis of a certain gas turbine blade-disc based on this method. The natural frequencies and natural modes of this blade-disc are obtained and also vibration characteristics of each natural mode and corresponding influence on gas turbine blade-disc and other components are discussed in detail. The analysis method and analysis results presented in this paper are helpful for further research on optimal design and vibration safety verification for this gas turbine blade-disc.

Geometric Error Compensation Methods of Numerical Control Machine Tool

2012 ◽  
Vol 426 ◽  
pp. 239-242
Author(s):  
Xiao Jun Wang ◽  
Xiao Guang Fu
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Reference Value ◽  
Geometric Error ◽  
Numerical Control ◽  
Control Machine Tool ◽  
Nc Machine Tool ◽  
Machining Center ◽  
Compensation Methods ◽  
Nc Machine

In this paper the characteristics of geometric errors is discussed in detail, error compensation methods used in productive practice and relevant examples are given. Finally, the application of error compensation in different situation is discussed according to the characteristics of machining center. The machine accuracy can be improved by error compensation. It has important practical reference value for reasonable use and maintaining of NC machine tool.

Optimization Design for the Large Gantry Machining Center Crossbeam

2011 ◽  
Vol 130-134 ◽  
pp. 2284-2287
Author(s):  
Qing Huang ◽  
Wei Fang Chen ◽  
Wen Hua Ye ◽  
Pei Huang Lou ◽  
Shi Hao Liu
Keyword(s):  
Optimization Design ◽  
Evaluation Method ◽  
Natural Frequencies ◽  
Machining Accuracy ◽  
Objective Functions ◽  
Optimization Analysis ◽  
Machining Center ◽  
Optimization Parameters ◽  
Static Performance ◽  
Performance Evaluation Method

The crossbeam is an important part in the gantry machining center which greatly affects the machining accuracy. Four kinds of crossbeam structure for the large machining center were designed and their static and dynamic characteristics were analyzed. The optimal crossbeam structure was selected by the comprehensive performance evaluation method. Then the thicknesses of rib plates in the crossbeam were defined as the optimization parameters after conducting the sensitivity analysis. The first four natural frequencies were defined as the objective functions and the static performance and the mass were defined as the constraint conditions. The optimal sizes of the rib plates in the crossbeam were obtained by the optimization analysis. Finally the feasibility of the result was demonstrated by the simulation. The result indicated that with the mass increased only by 0.18%, the first four natural frequencies of the optimal crossbeam were increased by 19.56%, 19.45%, 19.84%, 17.05%.

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