scholarly journals Position-Dependent Stability Prediction for Multi-Axis Milling of the Thin-Walled Component with a Curved Surface

2020 ◽  
Vol 10 (24) ◽  
pp. 8779
Author(s):  
Xiaojuan Wang ◽  
Qinghua Song ◽  
Zhanqiang Liu
Keyword(s):  
Material Removal ◽  
Variable Mass ◽  
Milling Process ◽  
Machining Process ◽  
Curved Surface ◽  
Structural Dynamic ◽  
Milling Stability ◽  
Integrated Method ◽  
Thin Walled ◽  
Cutting Path

Time-varying dynamic behaviors are essential to investigate the stability in the thin-walled workpiece milling process, which is usually affected by material removal and position-dependent characteristics of the workpiece along with the tool feed direction. To predict the milling stability with position-dependent, thin-walled component multi-axis milling, an improved structural dynamic modification method with variable mass is proposed in the paper. Firstly, the extraction of multi-axis milling material and the removal process of thin-walled parts with a complex curved surface and variable thickness is completed with CAM software. Then, the material removal of one cutting path as a modification of the structure is divided into multi-cutting steps with equal length to obtain the corrected FRFs in the machining process on the basis of the extended Sherman-Morrison-Woodbury formula. Furthermore, the dynamic characteristics of the initial un-machined workpiece and final machined workpiece are calculated by both experimental modal analysis and FEM. Finally, the multi-axis milling stability is predicted using the extended numerical integrated method, and an aero-engine blade is used to validate the accuracy and effectiveness of the proposed method for multi-axis milling molding parts.

Instantaneous Dynamics of Multi-Axis Milling Thin-Walled Workpiece with Complex Curved Surface

2016 ◽  
Vol 836-837 ◽  
pp. 529-535
Author(s):  
Gang Gang Ju ◽  
Qing Hua Song ◽  
Zhan Qiang Liu ◽  
Jia Hao Shi ◽  
Yi Wan ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Turbine Blades ◽  
Variable Mass ◽  
Milling Process ◽  
Cutting Process ◽  
Curved Surface ◽  
Structural Dynamic ◽  
Loading Effects ◽  
Thin Walled ◽  
Tool Position

The first step to predict the milling stability is to identify the dynamic characteristics of cutting process. And the mass loading effects of removal material play an important role on the dynamic characteristics of milling process for thin-walled parts, such as impeller, turbine blades and automobile components, which is changing with cutting time or tool position. Therefore, how to identify the instantaneous dynamic characteristics of milling process is one of the most significant problems. In the paper, a structural dynamic modification method with variable mass to predict the instantaneous dynamic characteristics of multi-axis milling thin-walled workpiece with complex curved surface is proposed. The proposed method takes into account the variations of dynamics characteristics of workpiece with the tool position and material removal. And the material cutting process is regarded as the structural dynamic modifications of cutting system, the instantaneous dynamic characteristics of which can be estimated by the extended Sherman-Morrison-Woodbury formula to obtain the corrected frequency response function (FRF). Experiments were carried out to obtain the instantaneous dynamics of a thin-walled workpiece and the results were verified by finite element method (FEM).

Modeling and Analysis Effects of Material Removal on Machining Dynamics in Milling of Thin-Walled Workpiece

2011 ◽  
Vol 223 ◽  
pp. 671-678 ◽  
Author(s):  
Ming Luo ◽  
Ding Hua Zhang ◽  
Bao Hai Wu ◽  
Ming Tang
Keyword(s):  
Material Removal ◽  
Dynamic Properties ◽  
Removal Rate ◽  
Milling Process ◽  
Machining Process ◽  
Machining Accuracy ◽  
Modeling And Analysis ◽  
Process System ◽  
Material Choice ◽  
Thin Walled

In aerospace industry, thin-walled workpieces are widely used in order to reduce the weight and to fulfill the high demands of their later applications. These workpieces are usually highly sophisticated and difficult to machine according to their geometry and material choice. In this paper, influence of material removal within the thin-walled workpiece machining operation on the dynamic properties of the workpiece and the machining process system is discussed. Aiming at learning about dynamic properties evolution during the machining operation, different milling processes of thin-walled plate are studied. Numerical simulation methods are employed in the study to investigate the dynamic properties evolution and machining stability with the material removal process in the milling process of thin-walled workpiece. The investigation results are expected to be used for designing optimized material removal sequence, which will guarantee highly material removal rate as well as highly machining accuracy of thin-walled workpiece.

scholarly journals Prediction of Dynamic Milling Stability considering Time Variation of Deflection and Dynamic Characteristics in Thin-Walled Component Milling Process

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Li Zhang ◽  
Weiguo Gao ◽  
Dawei Zhang ◽  
Yanling Tian
Keyword(s):  
Computational Model ◽  
Dynamic Characteristic ◽  
Dynamic Characteristics ◽  
Time Variation ◽  
Material Removal ◽  
Manufacturing Industry ◽  
Experimental Testing ◽  
Milling Process ◽  
Milling Stability ◽  
Thin Walled

The milling stability of thin-walled component is an important problem in the aviation manufacturing industry. The milling stability is influenced by both deflection characteristic and dynamic characteristic of workpiece. Moreover, in the material removal, the deflection and dynamic characteristics of workpiece are time-variant on the change of machining positions. Thus, the milling stability is also time-variant. In order to investigate the time variation of deflection and dynamic characteristics of workpiece, a new computational model was established in this paper. Based on the influences of the deflection and the dynamic characteristics of workpiece, a new stability lobes diagram which can show different stability domains and chatter domains in different process positions was obtained. Experimental testing has been conducted to validate the established new model.

Experimental study on cutting factors of multi-layer machining for large aerospace thin-walled structural parts

2021 ◽  
pp. 095440892110403
Author(s):  
Hangzhuo Yu ◽  
Han Zhong ◽  
Yong Chen ◽  
Lei Lin ◽  
Jing Shi ◽  
...  
Keyword(s):  
Coordinate System ◽  
Experimental Method ◽  
Cutting Parameters ◽  
Machining Process ◽  
Machining Error ◽  
Machining Errors ◽  
Inner Surface ◽  
Thin Walled ◽  
Optimal Cutting Parameters ◽  
Cutting Path

Large aerospace thin-walled structures will produce deformation and vibration in the machining process, which will cause machining error. In this paper, a cutting experimental method based on multi-layer machining is proposed to analyze the influence of cutting tool, cutting path, and cutting parameters on machining error in order to obtain the optimal cutting variables. Firstly, aiming at the situation that the inner surface of the workpiece deviates from the design basis, the laser scanning method is used to obtain the actual shape of the inner surface, and the method of feature alignment is designed to realize the unification of the measurement coordinate system and machining coordinate system. Secondly, a series of cutting experiments are used to obtain the machining errors of wall thickness under different cutting tools, cutting paths, and cutting parameters, and the variation of machining errors is analyzed. Thirdly, a machining error prediction model is established to realize the prediction of machining error, and the multi-objective optimization method is used to optimize the cutting parameters. Finally, a machining test was carried out to validate the proposed cutting experimental method and the optimal cutting parameters.

Stability Prediction during Thin-Walled Workpiece High-Speed Milling

2009 ◽  
Vol 69-70 ◽  
pp. 428-432 ◽  
Author(s):  
Qing Hua Song ◽  
Yi Wan ◽  
Shui Qing Yu ◽  
Xing Ai ◽  
J.Y. Pang
Keyword(s):  
High Speed ◽  
Dynamic Properties ◽  
Removal Rate ◽  
Cutting Parameters ◽  
Milling Process ◽  
Machining Process ◽  
High Speed Milling ◽  
Thin Walled ◽  
Optimization Of Cutting Parameters ◽  
Free Material

A method for predicting the stability of thin-walled workpiece milling process is described. The proposed approach takes into account the dynamic characteristics of workpiece changing with tool positions. A dedicated thin-walled workpiece representative of a typical industrial application is designed and modeled by finite element method (FEM). The workpiece frequency response function (FRF) depending on tool positions is obtained. A specific 3D stability chart (SC) for different spindle speeds and different tool positions is then elaborated by scanning the dynamic properties of workpiece along the machined direction throughout the machining process. The dynamic optimization of cutting parameters for increasing the chatter free material removal rate and surface finish is presented through considering the chatter vibration and forced vibration. The investigations are compared and verified by high speed milling experiments with flexible workpiece.

Cutting Path Design to Minimize Workpiece Displacement at Cutting Point: Milling of Thin-Walled Parts

2012 ◽  
Vol 6 (5) ◽  
pp. 638-647 ◽  
Author(s):  
Yusuke Koike ◽  
◽  
Atsushi Matsubara ◽  
Shinji Nishiwaki ◽  
Kazuhiro Izui ◽  
...  
Keyword(s):  
Cutting Force ◽  
Material Removal ◽  
Tool Orientation ◽  
Numerical Example ◽  
Path Design ◽  
Minimum Displacement ◽  
Low Stiffness ◽  
Thin Walled ◽  
Cutting Path ◽  
Cutting Point

Vibrations of a tool or workpiece during cutting operations shorten tool life and causes unwanted surface roughness. In this report, we propose an algorithm for determining the sequence of material removal, tool orientation, and feed directions, an algorithm minimizes workpiece displacements by considering workpiece stiffness and cutting force. In this research, the cutting path consists of the material removal sequence, tool orientation and feed directions. The material removal sequence changes the workpiece compliancematrix at the cutting points, and the feed directions and tool orientation change the direction of the cutting force. In our algorithm, workpiece displacements are reduced by changing the material removal sequence and applying the cutting force in the direction of higher workpiece stiffness. A numerical example demonstrates how the algorithm obtains appropriate cutting paths to mill a cantilever form. In the numerical example, three optimized cutting paths are compared with an unoptimized cutting path, a path used by an expert and based on the expert’s personal experience, to machine a low-stiffness workpiece. The obtained material removal sequence of the minimax compliance path is almost the same as that of the unoptimized cutting path. Workpiece displacements at the cutting point of three optimized cutting paths are approximately 10% smaller than those of the unoptimized cutting path. The minimum displacement path is the best of these three optimized cutting paths because fluctuations in workpiece displacements at cutting point are the smallest. These optimized cutting paths show the cutting path strategy as a rough cutting path for machining the thin-walled cantilever.

Milling Process Monitoring Based on Vibration Analysis Using Hilbert-Huang Transform

2018 ◽  
Vol 12 (5) ◽  
pp. 688-698 ◽  
Author(s):  
Agus Susanto ◽  
Chia-Hung Liu ◽  
Keiji Yamada ◽  
Yean-Ren Hwang ◽  
Ryutaro Tanaka ◽  
...  
Keyword(s):  
Signal Processing ◽  
Feature Extraction ◽  
Process Monitoring ◽  
Signal Analysis ◽  
Vibration Analysis ◽  
Milling Process ◽  
Machining Process ◽  
Hilbert Huang Transform ◽  
Thin Walled ◽  
Tool Damage

Vibration analysis is one method of machining process monitoring. The vibration obtained in machining is often nonlinear and of a nonstationary nature. Therefore, an appropriate signal analysis is needed for signal processing and feature extraction. In this research, vibrations obtained in the milling of thin-walled workpieces were analyzed using the Hilbert-Huang transform (HHT). The features obtained by the HHT served as machining-state indicators for machining process monitoring. Experimental results showed the effectiveness of the HHT method for detecting chatter and tool damage.

Machining Allowance Optimal Distribution of Thin-Walled Structure Based on Deformation Control

2017 ◽  
Vol 868 ◽  
pp. 158-165 ◽  
Author(s):  
Yu Zhi Chen ◽  
Wei Fang Chen ◽  
Rui Jun Liang ◽  
Ting Feng
Keyword(s):  
Cutting Force ◽  
Element Model ◽  
Optimization Method ◽  
Milling Process ◽  
Machining Process ◽  
Machining Accuracy ◽  
Side Milling ◽  
Deformation Control ◽  
Thin Walled ◽  
Relationship Of

Multilayer cutting is widely used in finish machining process of thin-walled parts to improve the machining precision. The paper presents a cutting allowance optimization method using genetic algorithm to improve the machining quality and efficiency of thin-walled parts in the field of aerospace. Considering the coupling relationship of the deformation between the layers in layered milling, the parameterized finite element model of thin-walled parts in side milling process is established. The best relationship between the workpiece stiffness and the cutting force is determined though iterative calculations, and the deformation caused by the cutting force can be minimized. The results show that the optimized distribution of the depth of finishing cutting was better than the experience. The method proposed in this paper can reduce the deformation of the workpiece during the machining process, and thus improve the machining accuracy.

Deformation Analysis of Thin-Walled Workpiece under Multi-Stress Coupled Effect

2010 ◽  
Vol 426-427 ◽  
pp. 284-288
Author(s):  
Dong Lu ◽  
Guo Hua Qin ◽  
Yi Ming Rong ◽  
C.M. Peng
Keyword(s):  
Initial Stress ◽  
Coupled Model ◽  
Element Model ◽  
Milling Process ◽  
Machining Process ◽  
Deformation Analysis ◽  
Milling Force ◽  
Thin Walled ◽  
And Control ◽  
The Finite Element Model

This document Cutting stress coupled with clamping stress and initial stress affects the workpiece deformation. To analyze the workpiece deformation the initial stress model is developed. The finite element model of milling process is established and the milling force and milling heat is predicted. The multi-stress coupled model is developed and the workpiece deformation during machining process and deformation after fixtures released are predicted. This study is helpful to predict and control the deformation for thin-walled workpiece.

Stability Prediction of Milling Process With Closed Machining System Dynamics With Flexible Thin-Walled Workpiece

2015 ◽  
Author(s):  
Chao Xu ◽  
Pingfa Feng ◽  
Dingwen Yu ◽  
Zhijun Wu ◽  
Jianfu Zhang
Keyword(s):  
Support System ◽  
Milling Process ◽  
Machining Process ◽  
Stability Lobe Diagram ◽  
Closed Model ◽  
Flexible Support ◽  
Stability Lobe ◽  
Machining System ◽  
Thin Walled ◽  
The Stability

Despite recent advances and improvements in modeling and prediction of the dynamics of the machining process, an efficient machining process is limited due to chatter and instability of machining system. In fact, the machining system contains various kinds of joints, which cause difficulties in dynamics modeling, simulation and prediction. Moreover, the flexible support system results in large deformation and violent vibration of the workpiece when machining, and the thin-walled workpiece easily gives rise to the chatter of the machining system. Therefore, the dynamics of the flexible support system was considered to calculate stability lobe diagram in the modeling of milling process. The whole machining system was regarded as a closed loop composed by the machine tool structures, support, workpiece and machining process. In this paper, the receptance coupling (RC) method was introduced to predict the dynamics of the closed machining system. A milling process was taken for example to predict the chatter limitations using the dynamics of closed model. The mathematical model of the machining system (machine tool structures, spindle, holder and tool), together with the details of joint contacts, was given based on the RC method. The RC model was used to obtain the dynamics of the system, while receptance of the tool point was coupled. Based on the coupling model of the machining system, the depth limitations under different speeds were estimated for the technology parameter optimization in milling process. The response was considered to be the sum of the cutting point and the support system. The flexibility of the support system was considered to be the feedback of the cutting stiffness. By this means, the traditional model was modified to calculate the stability lobe diagram based on the dynamics of the spindle and support system. Furthermore, the milling experiment was carried out to verify the prediction results, and the dominant natural frequencies of receptance at tool point were obtained by modal testing to define the stability lobe diagram. It was found that the chatter results matched well with the stability lobes. It was concluded that the support system with poor stiffness might cause violent chatter especially when the workpiece was thin-walled. The cutting depth limitations of the flexible support system were lower than that of the rigid one. Moreover, this closed model of the machining system is appropriate for the chatter prediction of the flexible support system or thin-walled workpiece, so it is helpful for a better parameter optimization.

Sign in / Sign up

Export Citation Format

Share Document