Wei Liang

Bio: Wei Liang is an academic researcher from Osaka University. The author has contributed to research in topics: Welding & Deformation (meteorology). The author has an hindex of 6, co-authored 12 publications receiving 680 citations.

Prediction of Welding Distortion by Elastic Finite Element Analysis using Inherent Deformation Estimated Through Inverse Analysis

Abstract: During welding, deformation is produced as an unavoidable consequence. The inherent deformation method, in which the inherent deformation is introduced into the elastic finite element method (FEM) as the initial strain, is one of the effective methods to predict the welding distortion of large structures. However, the values of the inherent deformations for all weld joints included in the structure must be known beforehand. Generally, the inherent deformations are influenced by various factors such as materials, welding method, welding condition, joint geometry, plate thickness, and weld length. Thus, it is meaningful to develop a simple method to obtain the inherent deformation. In this report, a simple and efficient method to estimate inherent deformation of typical weld joints is proposed. Further, using the estimated inherent deformation, the welding deformation of joint specimens and large plate structures are predicted.

Understanding the effect of laser scan strategy on residual stress in selective laser melting through thermo-mechanical simulation

Abstract: Selective laser melting (SLM) is an attractive technology, enabling the manufacture of customised, complex metallic designs, with minimal wastage. However, uptake by industry is currently impeded by several technical barriers, such as the control of residual stress, which have a detrimental effect on the manufacturability and integrity of a component. Indirectly, these impose severe design restrictions and reduce the reliability of components, driving up costs. This paper uses a thermo-mechanical model to better understand the effect of laser scan strategy on the generation of residual stress in SLM. A complex interaction between transient thermal history and the build-up of residual stress has been observed in the two laser scan strategies investigated. The temperature gradient mechanism was discovered for the creation of residual stress. The greatest stress component was found to develop parallel to the scan vectors, creating an anisotropic stress distribution in the part. The stress distribution varied between laser scan strategies and the cause has been determined by observing the thermal history during scanning. Using this, proposals are suggested for designing laser scan strategies used in SLM.