Residual Stress Analysis of a 2219 Aluminum Alloy Ring Using the Indentation Strain-Gauge Method

Yunlong Ma,Nianpu Xue,Jian Wu,Hanjun Gao,Qiong Wu

doi:10.3390/met10070979

Abstract

Aerospace thin-walled rings are vulnerable to machining distortion during the manufacturing process. Various research results show that the main factor causing machining deformation is initial residual stress inside the blank. In this study, the residual stress of a 2219 aluminum alloy ultra-large rolling ring was measured by using the indentation strain-gauge method. Results showed the maximum residual maximum principal stress was +265 MPa and stress distribution was uneven. To homogenize the initial residual stress of the ring, an expansion method is proposed based on the principle of pre-stretching plate, and the feasibility of the expansion method was analyzed by establishing a simplified theoretical model of ring. A FE (Finite Element) model was established to investigate residual-stress evolution during the rolling ring and the expanding ring process. The expansion simulation results show that the reduction rates of residual stress were greater than 40% and the maximum residual stress was only 65 MPa.

Highlights

Monolithic thin-walled parts are widely used in the aviation and aerospace production due to their high specific stiffness and strength
Yang et al [4] found that initial residual stress was the main effect of machining distortion for aluminum alloy aircraft monolithic components
The stress result showed that both tensile stress and compressive stress rolling ring, respectively

Summary

Introduction

Monolithic thin-walled parts are widely used in the aviation and aerospace production due to their high specific stiffness and strength. Their thin-walled parts are manufactured by turning and milling, in which case, more than 90% of the material is removed from the blank [1]. Huang et al [3] believed that the coupling of initial compressive residual stress and machining-induced residual stress increased the machining distortion for 7050-T7451 alloy plate. Yang et al [4] found that initial residual stress was the main effect of machining distortion for aluminum alloy aircraft monolithic components. Huang et al [5] concluded that initial residual stress caused difficulty of subsequent welding processes for multipart structures. The homogenization of initial residual stress becomes more important for solving machining deformation

Methods

Results

Discussion

Conclusion