Effects of Residual Stress and Equivalent Bending Stiffness on the Dimensional Stability of the Thin-Walled Parts

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.

A novel multi-pass machining accuracy prediction method for thin-walled parts

“…They built an error prediction model considering part deformation based on neuro-fuzzy networks. 2) For the stiffness, finite element analysis methods are widely used to calculate it [18,19]. The initial stiffness of TWP can also be obtained based on physical measurement [2].…”

“…In addition, Li et al [20] studied the impact of TWP equivalent bending stiffness on the machining deformation based on experiments and finite element simulations. Gao et al [18,21] investigated the effect of stiffness on dimensional stability. They improved the TWP bending strength based on topology optimization techniques to achieve deformation control.…”

Topology optimization-driven design of added rib architecture system for enhanced free vibration response of thin-wall plastic components used in the automotive industry

“…For instance, Yasin et al [23] advocates for SIMPbased topology optimization for the design of a ribs system attached to a plastic cover protector with the aim of reducing warpage associated with its mold injection manufacturing process. Gao et al, [24] addresses the topology optimizationdriven design of rib stiffeners for increased bending stiffeners of thin-wall components used in the aeronautics and aerospace sectors. Furthermore, the authors in [25] devised a new smart topology optimization algorithm for support-free designs, showing promising results from the manufacturing standpoint.…”