A machining deformation control method of thin-walled part based on enhancing the equivalent bending stiffness

2020 ◽  
Vol 108 (9-10) ◽  
pp. 2775-2790
Author(s):  
Bianhong Li ◽  
Hanjun Gao ◽  
Hongbin Deng ◽  
Chao Wang
2021 ◽  
Author(s):  
Hanjun Gao ◽  
Xin Li ◽  
Qiong Wu ◽  
Minghui Lin ◽  
Yidu Zhang

Abstract The monolithic thin-walled parts are widely used in the aeronautic and astronautic field because of its excellent mechanical performance and light weight, but the thin-walled parts are vulnerable to the machining deformation due to its low stiffness and high material removal rate. According to the relative basic theory, the stiffness and internal residual stress of the part are the critical factors affecting the dimensional stability. In this work, the influences of equivalent bending stiffness and residual stress on the dimensional stability of thin-walled parts are studied. Nine typical thin-walled parts in three groups with two materials (7075 aluminum alloy for A1~A3 and B1~B3, and Ti6Al4V titanium alloy for B4~B6) are machined and treated with different processes. Topology optimization technique is used to optimize the structure of parts to enhance the bending stiffness. Corresponding finite element method (FEM) simulations are carried out to further investigate the generation mechanism. The deformations in 312 hours after machining are measured using coordinate measuring machine, and the deformation changes of the parts are obtained and analyzed. Finally, based on topological optimization and stress relief technology, a machining deformation control method for the monolithic thin-walled parts is proposed. Results show that the maximum and average deformations of thin-walled are evidently decreased using the proposed method.


2021 ◽  
Vol 15 ◽  
Author(s):  
Song Yang ◽  
Jun-Xue Yang ◽  
Fei-Yue Wang

Background: To reduce environmental pollution and improve resource utilization, lightweight equipment has become an important development trend of manufacturing. Therefore, thin-walled parts are being widely used in automobiles, aerospace, etc. due to their lightweight and high specific strength. However, they usually deform during machining due to poor stiffness. Objective: To reduce the machining deformation, the finite element method has been used to analyze the deformation law of thin-walled parts. Method: A 3D milling model of Al7050-T7451 thin-walled parts was established. Then, the influence of hole structure, rib, and auxiliary support on the deformation was investigated under the condition of optimized parameters. Moreover, some related patents on the research of machining deformation of thin-walled parts were also consulted. Results: The results showed that the established 3D model could accurately predict the machining deformation of thin-walled parts. The machining deformation on the edges is more severe due to holes that weaken the stiffness of thin-walled parts. Besides, ribbed slab and auxiliary support can shorten machining deformation by 71.9% and 65.2%, respectively.


2011 ◽  
Vol 188 ◽  
pp. 314-318
Author(s):  
Bao Hai Wu ◽  
Ming Luo ◽  
Ding Hua Zhang ◽  
X. Zhou

This paper deals with deformation control and chatter suppression in the milling of thin-walled blade. The purpose is to generate tool paths that can control machining deformation and suppress chatter during milling. To achieve this object, symmetrical spiral milling approach is proposed to release residual stress on both sides of the blade in the same machining circle to control machining deformation. Besides, in order to suppress chatter during milling of thin-walled blade, nonuniform-allowance is left on both sides of the blade during machining, this can effectively increase the rigidity, thereby chatter cannot easily occur during machining. Machining experiments showed that the proposed approaches can dramatically improve the machining quality, decrease deformation and suppress chatter in the milling of thin-walled blade.


2020 ◽  
Vol 34 (29) ◽  
pp. 2050272
Author(s):  
Yi Chen ◽  
Shaoxing Ma ◽  
Jinxing Kong ◽  
Wen Huang

Thin-wall parts have the advantages of light weight and high structural strength and are widely used in industrial fields. As the increasing requirements for the form accuracy and surface quality, ultra-precision cutting has been increasingly used to manufacture thin-walled parts. However, due to the small effect range (less than 10 [Formula: see text]m) of residual stress caused by ultra-precision cutting, it cannot be accurately measured by the conventional methods. Therefore, the research on the residual stress and deformation of thin-walled parts under ultra-precision cutting are currently restricted. In this paper, we first introduced the GIXRD method to solve the technology absence for measuring the ultra-precision cutting conducted residual stress. Based on GIXRD, TEM and dynamic interferometer measurement, the relationship between grain state, residual stress and deformation of thin-walled parts was established. The research works had shown that reducing the cutting depth within a certain range was beneficial to reduce residual stress and deformation. However, there was an extreme point of the cutting parameter. If this extreme point was exceeded, the cutting action would gradually transform from shearing to pressing and pushing, resulting in an increase in residual stress. Therefore, there was an extremely small cutting parameter that minimized residual stress and deformation of the thin-walled member. The results were helpful to understand the mechanism of deformation of thin-walled parts from the perspective of grain size and residual stress, and accordingly established a deformation control method.


2012 ◽  
Vol 426 ◽  
pp. 265-269
Author(s):  
Zhao Liang Jiang ◽  
Y.M Liu ◽  
W. Yi

Unexpected work-piece deformation during the course of milling will lead to part bending or distorting, which is critical to get its quality performance lower. In this paper, a novel process based deformation control method is proposed using High Definition Metrology (HDM). Main factors that affect machining deformation of work-piece are analyzed firstly. Then process based deformation control model is made, which divides one machining process into four stages. The surface flatness data of work-piece at each stage are obtained respectively. Finally, the practicality and effectiveness of this new approach is verified using the case of Aluminum alloy 6061 part milling.


2021 ◽  
Vol 60 (1) ◽  
pp. 631-642
Author(s):  
Yan Xu ◽  
Zhongjun Shi ◽  
Bianhong Li ◽  
Zhang Zhang

Abstract Residual stress generated during the blank forming and machining process significantly influences the dimensional stability of the mechanical parts. The equivalent bending stiffness and thermal vibration stress relief (TVSR) are two factors that affect the deformation of thin-walled workpiece. To increase the machining accuracy, on the one hand, increase the equivalent bending stiffness in manufacturing, and on the other hand, usually conduct the stress relief process to reduce the residual stress in manufacturing. In the present study, morphology optimization and TVSR process are conducted on a thin-walled part Specimen B of 7075 aluminum alloy to control the residual stress and machining deformation before finish machining. As a contrast, Specimen A is machined in one step. The deformations vary with time of Specimen A and B are measured. The corresponding finite element model is built to further study the stress and distortion during the machining process. Results showed that (1) deformation decreased with the increase of equivalent bending stiffness, compared with Specimen A, the maximum deformation of Specimen B decreased by 58.28%. (2) The final maximum deformation of Specimen B can be reduced by 38.33% by topology reinforcement to improve the equivalent stiffness and TVSR to reduce the residual stress.


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