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

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.

Numerical Simulation and Experiment of Stress Relief and Processing Deformation of 2219 Aluminum Alloy Ring

“…The vibration equation of the components is shown in equations (2-4) [36]. (2)(3)(4) where X -vibration displacement; M -Total vibration mass; m -Rotor eccentricity mass; e -Eccentricity;  -The ratio of vibration frequency k to natural frequency k0; Y -Damping ratio.…”

“…From the above analysis, it can be seen that at the natural frequency of the component, in equations (2-4) λ= 1. From this, the vibration equation amplitude A shown in equation (2-4) can be obtained as shown in equation (2)(3)(4)(5). (2)(3)(4)(5) In general, loading at the peak of a component is more likely to reach the yield limit of the material, thereby reducing residual stress.…”

“…From this, the vibration equation amplitude A shown in equation (2-4) can be obtained as shown in equation (2)(3)(4)(5). (2)(3)(4)(5) In general, loading at the peak of a component is more likely to reach the yield limit of the material, thereby reducing residual stress. This article selects the relative total deformation of the surface nodes on the ring based on the 7th order vibration mode of the ring, as shown in Figure A4b, and then multiplies it by a proportional coefficient p to replace the amplitude A.…”

“…The largest integral rolling ring has a diameter of nearly 10 meters and a wall thickness of about 0.2 meters. When processing large thin-walled rolling ring parts, they are prone to machining deformation caused by residual stress [4]. In addition, thin-walled parts are manufactured through turning and milling, in which more than 90% of the material is removed from the billet.…”

Evolution of stress and strain in 2219 aluminum alloy ring during roll-bending process

“…LV, Nan studied a long-term natural aging treatment method, explored and veri ed the effect of natural aging and arti cial aging on homogenizing and reducing in ferrule [12]. Ma used indentation strain gauge method to study the residual stress of 2219 aluminum alloy super large rolled ring [13]. GP Dolan uses quenching factor analysis to slowly cool the alloy from the solution heat treatment temperature to the intermediate temperature above the critical temperature region of the C curve.…”