A control process for machining distortion by using an adaptive dual-sphere fixture

Abstract

Blades are affected by clamping, cutting forces, and residual stress, thus resulting in warping and distortion because of the thin wall and free surfaces. In this paper, a new process for the control of machining distortion is proposed to eliminate surface errors by using an adaptive dual-arm fixture. First, some causes of distortion by different machining methods are discussed. Second, an adaptive mechanism with eight degrees of freedom is designed to allow the blade to be clamped under an unstressed state and to enable the release of stress at any time. Thereafter, a dual-sphere fixture is designed on the basis of the adaptive mechanism. Finally, by adopting this process based on the adaptive dual-arm fixture, machining distortion is reduced after releasing stress several times. Experimental results show that the process can eliminate 50 % of surface errors in machining. Therefore, a test blade machined by the proposed process will exhibit improved precision.

Machining deformation analysis of aircraft monolithic components based on the energy method

“…In the region I, the deformation energy of the material removed acts above the neutral axis; in the region II, the deformation energy of the material removed acts below the neutral axis. The energy V ε of the removed material can be obtained from formula (3) (4) and (5). Figure 5 shows the change law of effective deformation energy in rolling direction according to the above analysis.…”

“…After machining, they deformed easily. Machining deformation of aircraft monolithic components resulted by the combined action of many factors, including blank residual stress, machining residual stress, components geometry clamping conditions, et al [3][4][5].…”

Research on machining error transmission mechanism and compensation method for near-net-shaped jet engine blades CNC machining process

“…Bandy HT et al [21] proposed a methodology for compensating for errors detected by process-intermittent inspection, and this methodology was validated on a prototype system implemented by processintermittent error compensation software (PIECS) on a turning center. Jian-Hua Yu et al [22] proposed a new method for controlling machining deformation by eliminating surface errors based on an adaptive two-armed fixture, and adaptive technology has been applied in the design and process integration of a fixture. Nuodi Huang et al [23] processed an adaptive deformation error compensation method for a large thin-walled part, and an integrated on-board measurement (OMM) system was developed to obtain the geometry of the part for a typical large thin-walled part for the tank bottom of a rocket, and a machining error compensation algorithm was developed to eliminate deformation errors by modifying machining tool paths.…”

Machining Deformation Analysis of Aircraft Monolithic Components based on the Energy Method

“…Characteristics of aircraft monolithic components are large size, complex structure, and low stiffness because of the material removal rate of more than 93%., Aircraft monolithic components deformed easily after machining. Machining deformation of aircraft monolithic components resulted by the combined action of many factors, including blank residual stress, machining residual stress, components geometry clamping conditions, et al [3][4][5].…”