Study on Method for Weak Link Identification of Dynamic Stiffness of a Machine Tool and Optimization Design

2013 ◽  
Vol 49 (21) ◽  
pp. 11 ◽  
Author(s):  
Changliang YU
Keyword(s):  
Machine Tool ◽  
Optimization Design ◽  
Weak Link ◽  
Dynamic Stiffness

Weight-Reduction Optimization Design for Milling Planer Bed Based on Finite Element Analysis

2012 ◽  
Vol 490-495 ◽  
pp. 2785-2789
Author(s):  
Dong Sun ◽  
Xu Dong Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Weight Reduction ◽  
Optimization Design ◽  
Weak Link ◽  
Three Dimensional ◽  
Production Costs ◽  
Element Analysis ◽  
Before And After ◽  
Improvement Scheme

The milling planer bed is one of the most important foundational parts for the entire machine, sufficient stiffness is required. The posterior segment of a certain milling planer bed is regarded as the optimization object in this paper. Three-dimensional modeling method is used to calculate the exact weight of the bed and then finite element analysis is used to research the static and dynamic characteristics before and after weight-reduction. The weak link of the bed is found out and a improvement scheme is put forward ensuring lower production costs under the premise of sufficient rigidity.

Dynamic Analysis of Helical Milling Unit Based on Virtual Machine Tool

2011 ◽  
Vol 188 ◽  
pp. 463-468 ◽  
Author(s):  
Xu Da Qin ◽  
Qi Wang ◽  
H.Y. Wang ◽  
Song Hua
Keyword(s):  
Machine Tool ◽  
Virtual Machine ◽  
Dynamic Stiffness ◽  
Three Dimensional ◽  
Geometrical Model ◽  
Helical Milling ◽  
Response Analysis ◽  
Computer Simulation Model ◽  
Element Analysis ◽  
Virtual Machine Tool

The virtual prototype is a computer simulation model of the physical product that can be analyzed like a real machine. This paper studies the helical milling unit based on the virtual machine tool. The helical milling unit is first designed according to the kinematics of the helical milling. The main parts of the equipment include rotating mechanism, orbital agency and radial offset organization. Based on the feasibility analysis of the structure, the three-dimensional geometrical model is built in the Solidworks software. The key parts in the model are separated from the device and introduced into the finite element analysis (FEA) software, according to the cutting loads tested from experiment, static and dynamic modal analysis and harmonic response analysis are carried out for the key parts of this device. The results show that the static and dynamic stiffness can meet design requirement.

Weak-Points Diagnosis and Optimization of Shield Machine Cutter Tool Based on Characteristic Parameters

2016 ◽  
Vol 693 ◽  
pp. 1479-1485 ◽  
Author(s):  
Jian Zhao ◽  
Xue Wu Hong ◽  
Ming Yu ◽  
Zhi Peng Gao ◽  
Wen Jin Wang
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
Optimization Design ◽  
Weak Link ◽  
Human Life ◽  
Element Model ◽  
Ring Structure ◽  
Modal Parameters ◽  
Underground Engineering ◽  
Shield Machine

Shield machine plays an indispensable role in the mining, transportation, underground engineering, hydraulic engineering and municipal construction. Shield cutters of shield construction process often appears serious deformation, damage that leads to engineering accident, or even a threat to human life and safety. In order to provide high precise data for shield machine cutter tool dynamic modification and to diagnose the shield machine cutter tool fault, the dynamic characteristic of the shield machine cutter tool system, which is the main component of a shield machine cutter tool, has to be obtained precisely. The compute modal parameters identification method base on the finite element method is proposed to identify the modal parameters of the shield machine cutter tool. By means of Solidwords software, the knife ring structure of the shield machine tool and the tool is designed; then build the tool the finite element model, modal analysis, obtained the dynamic characteristics, and find out the weak link, put forward the improvement measures and prolong its life. Therefore, the study on dynamic characteristics of shield machine cutter, for the optimization design of domestic tool, has an important significance improve tool life.

Dynamic optimization method with applications for machine tools based on approximation model

2017 ◽  
Vol 232 (11) ◽  
pp. 2009-2022 ◽  
Author(s):  
TJ Li ◽  
XH Ding ◽  
K Cheng ◽  
T Wu
Keyword(s):  
Machine Tool ◽  
Performance Optimization ◽  
Machine Tools ◽  
Optimization Design ◽  
Natural Frequencies ◽  
Dynamic Performance ◽  
Machining Process ◽  
Machining Accuracy ◽  
Approximation Model ◽  
Dynamic Behaviors

Natural frequencies and modal shapes of machine tools have position-dependent characteristics owing to their dynamic behaviors changing with the positions of moving parts. It is time-consuming and difficult to evaluate the dynamic behaviors of machine tools and their machining accuracy at different positions. In this paper, a Kriging approximation model coupled with finite element method is proposed to substitute the dynamic equations for obtaining the position-dependent natural frequencies of a machine tool, as well as relative positions between the tool and the workpiece during the machining process. Based on the proposed method, dynamic performance optimization design of the machine tool is conducted under the condition of minimum relative positions. Three case studies are illustrated to demonstrate the implementation of the proposed method.

Dynamic Characteristics Analysis and Structural Topology Optimization of the Plane Grinder

2016 ◽  
Vol 693 ◽  
pp. 471-478
Author(s):  
Rui Tao Peng ◽  
Wang Yan ◽  
Xin Zi Tang ◽  
Zhuan Zhou
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristics ◽  
Weak Link ◽  
Element Model ◽  
Variable Density ◽  
Structural Topology ◽  
Static And Dynamic Characteristics ◽  
Before And After ◽  
Characteristics Analysis ◽  
Dynamic Characteristics Analysis

The dynamic characteristic is one of the important indicators which determine the performance of a machine tool, in this paper, the finite element model of a plane grinder is established with consideration of the behavior of joint, the static dynamic characteristics of machine tools are analyzed to reveal the vibration weak link, the column structure is topology optimized and redesigned based on the variable density degradation method. Static and dynamic characteristics of the original and new column are compared, and the dynamic characteristics of the machine tool before and after modification are discussed. The results indicate that the static and dynamic characteristics of the plane grinder are all improved after optimization.

scholarly journals Analysis on Dynamic Contact Characteristics and Dynamic Stiffness Estimating Method of Single Nut Ball Screw Pair Based on the Whole Rolling Elements Model

2020 ◽  
Vol 10 (17) ◽  
pp. 5795
Author(s):  
Ye Chen ◽  
Chunyu Zhao ◽  
Zhenjun Li ◽  
Zechen Lu
Keyword(s):  
Machine Tool ◽  
Mass Production ◽  
Contact Stiffness ◽  
Dynamic Stiffness ◽  
Dynamic Contact ◽  
Ball Screw ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Feed System ◽  
Stiffness Model

The purpose of this paper is investigating the characteristics of dynamic contact and dynamic stiffness of the single nut ball screw pair (SNBSP). Then a new sensorless method is proposed to extract the SNBSP dynamic contact stiffness of a mass production CNC machine tool feed system. First of all, the transformation relationship between each coordinate system of SNBSP is established. Secondly, the dynamic model of all ball–raceway contact pairs is established. Based on this, a dynamic contact stiffness model is established. The dynamic contact parameters are obtained by the numerical method. It is found that the influence of screw speed on screw and nut raceway normal force distribution are opposite. This will affect the variations of dynamic contact stiffness. It is also clear that the effect of axial load on dynamic stiffness is significant. Then, an effective method is proposed to estimate the dynamic contact stiffness of a mass production CNC machine tool feed system without any external sensors. The axial force of feed system is estimated by using torque current of servo motor. Current signals can be obtained through FANUC Open CNC API Specifications (FOCAS) library functions, and then dynamic contact stiffness can be calculated through the stiffness model without external sensors. Finally, a feed system dynamic model is built, and the contact model and sensorless stiffness estimating method are verified by experiments in this dynamic system.

Modeling and Synchronous Control of Dual Mechanically Coupled Linear Servo System

2014 ◽  
Vol 137 (4) ◽  
Author(s):  
Wu-Sung Yao
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Dynamic Stiffness ◽  
System Modeling ◽  
Coupled System ◽  
Mechanical Coupling ◽  
Synchronous Control ◽  
Linear Motors ◽  
Operation Speed ◽  
Control Scheme

This paper presents a system modeling technique for a high-speed gantry-type machine tool driven by linear motors. One feed axis of the investigated machine tool is driven by the joint thrust from two parallel linear motors. These two parallel motors are coupled mechanically to form the Y-axis while another standalone motor fixed to a support forms the X-axis. The components in the X-axis, which is treated as the mechanical coupling, are carried by the slides of the Y-axis motors. This configuration is applied to improve the dynamic stiffness of the system and operation speed/acceleration. However, the precise synchronous control of the two parallel and coupled motors would be the major challenge. To overcome this challenge, a multivariable system identification method is developed in this paper. This method is used to construct an accurate system mathematical model for the target coupled system. A synchronous control scheme is then applied to the model obtained using the proposed technique. The performance of the system is experimentally verified with a high-speed S-curve motion profile. The results substantiate the constructed system model and demonstrate the effectiveness of the control scheme.

Analyzing of Dynamic Characteristics of Special CNC Machine Tool

2010 ◽  
Vol 29-32 ◽  
pp. 2037-2041
Author(s):  
Ke Wang ◽  
Guang Lv ◽  
Xing Wei Sun
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristics ◽  
Optimization Design ◽  
High Efficiency ◽  
Structural Parameters ◽  
Force Frequency ◽  
Cutting Method ◽  
Finite Element Software ◽  
Exciting Frequency ◽  
Motion Parameters

The dynamic characteristics of machine tool is an important factor, which make affect on the cutting stability of machine tool. The poor dynamic characteristics will seriously affect the stability of cutting, make the low cutting efficiency and low machining precision, and also accelerate the wear of tools and even reduce the machine’s service life. So it is necessary to analyze the dynamic characteristics of machine tool, and according to the results of analysis to optimize structural parameters and motion parameters of the machine tools. This paper analyses the dynamic characteristics of machine bed and machined work piece of the CNC special machine tool for Kelly with the finite element software, and analysis of excitation characteristics of cutting tool. It also makes optimization design to the machine bed, through the analysis and optimization, the natural frequency and stiffness will be obviously improved. According to the structure and calculation of the motion parameters we can get the exciting force frequency to workpiece when it is cut, using interlocking tooth cutting method to replace the initial symmetrical cutting method in order to avoid the resonance produced in the cutting process and improve stability. The exciting frequency when cutting can be improved and the probability of resonance when cutting is lowered. All these ensure high efficiency and high stability cutting.

Experimental Research Regarding the Influence of Hydraulic Resistances on the Hydrostatic Guideways Stiffness

2014 ◽  
Vol 657 ◽  
pp. 475-479
Author(s):  
Marius Pascu ◽  
Gheorghe Stan
Keyword(s):  
Machine Tool ◽  
Hydraulic Resistance ◽  
Experimental Research ◽  
Machine Tools ◽  
Dynamic Stiffness ◽  
Experimental Results ◽  
Graphical Form ◽  
Experimental Setup ◽  
Experimental Database ◽  
Supply Circuit

A very important factor for the hydrostatic guideways is given by the presence of the restrictor on the supply circuit, whose hydraulic resistance may have important effects on the lubricant film behaviour and implicitly, on the static and dynamic stiffness of the system. This paper presents a new method of experimental research regarding the hydrostatic guideway stiffness, depending on the hydraulic resistances values which supply each pocket. During the experiments which approach the influence of the hydraulic resistances values of the restrictors on the hydrostatic guideway stiffness, a centered constant loads of 20, 50 and 100 [daN] was used. The experiments were carried out on an experimental setup composed of an open hydrostatic guideway, having the pocket dimensions of 150x88 [m, supplied with liquid under pressure through means of a pack of adjustable restrictors. The obtained experimental results are presented in both tabular and graphical form and constitute an experimental database which can be used by the machine tools designers and manufacturers. The paper contains recommendations regarding the usage of hydraulic resistances values depending on the machine tool type and size. Also, from the obtained results, recommendations can be made with regard to the type of restrictors to be used, so that the lubricant filtration grade is comprised between admissible values.

Evaluation of dynamic stiffness of machine tool spindle by non-contact excitation tests

CIRP Annals ◽  
2015 ◽  
Vol 64 (1) ◽  
pp. 365-368 ◽  
Author(s):  
Atsushi Matsubara ◽  
Shota Tsujimoto ◽  
Daisuke Kono
Keyword(s):  
Machine Tool ◽  
Dynamic Stiffness ◽  
Machine Tool Spindle
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