Finite Element Analysis of Residual Stress in Ti-6Al-4V Alloy Plate Induced by Deep Rolling Process under Complex Roller Path

Abstract

The kinematics of the deep rolling tool, contact stress, and induced residual stress in the near-surface material of a flat Ti-6Al-4V alloy plate are numerically investigated. The deep rolling tool is under multiaxis nonlinear motion in the process. Unlike available deep rolling simulations in the open literature, the roller motion investigated in this study includes penetrative and slightly translational motions. A three-dimensional finite element model with dynamic explicit technique is developed to simulate the instantaneous complex roller motions during the deep rolling process. The initial motion of the rollers followed by the penetration motion to apply the load and perform the deep rolling process, the load releasing, and material recovery steps is sequentially simulated. This model is able to capture the transient characteristics of the kinematics on the roller and contacts between the roller and the plate due to variations of roller motion. The predictions show that the magnitude of roller reaction force in the penetration direction starts to decrease with time when the roller motion changes to the deep rolling step and the residual stress distributions in the near-surface material after the material recovery step varies considerably along the roller path.

Impact of the Process Parameters, the Measurement Conditions and the Pre-Machining on the Residual Stress State of Deep Rolled Specimens

“…Despite of the clear benefits of deep rolling (DR), the controlled generation of compressive RS is still a challenging task, due to several factors like the numerous of available process parameters and the stress state influenced by the pre-machining of the treated material. To date, the exact prediction of the RS state after deep rolling has still not been achieved, despite the available common knowledge about the impact of the mostly important process parameters, gathered by extensive research studies throughout the past decades [8,9]. The finite element analysis, being in most cases already a decisive phase of process modelling, took also its place among the scientific work on topic modelling and prediction of the process output variables by DR.…”

The Metal Surface Layer Mechanical Condition Transformation in Machining Processes

“…Currently, the surface layer (SL) predominant role in ensuring the machine parts durability is generally recognized [1][2][3][4][5][6][7][8][9][10][11][12][13]. Especially the part surface layer, which forming throughout the manufacture technological process, receives the greatest loading during operation.…”