Jianguo Lin

Bio: Jianguo Lin is an academic researcher from Imperial College London. The author has contributed to research in topics: Hot stamping & Creep. The author has an hindex of 41, co-authored 319 publications receiving 6679 citations. Previous affiliations of Jianguo Lin include Coventry Health Care & University of Birmingham.

A review of spinning, shear forming and flow forming processes

Abstract: In the last two decades or so, spinning and flow forming have gradually matured as metal forming processes for the production of engineering components in small to medium batch quantities. Combined spinning and flow forming techniques are being utilised increasingly due to the great flexibility provided for producing complicated parts nearer to net shape, enabling customers to optimise designs and reduce weight and cost, all of which are vital, especially in automotive industries. In this paper, process details of spinning and flow forming are introduced. The state of the art is described and developments in terms of research and industrial applications are reviewed. Also, the direction of research and development for future industrial applications are indicated.

Investigation of deformation and failure features in hot stamping of AA6082: Experimentation and modelling

Abstract: This paper introduces a set of coupled viscoplastic constitutive equations for deformation and damage in hot stamping and cold die quenching of AA6082 panel parts The equation set can be used to predict viscoplastic flow and plasticity-induced damage of AA6082 under hot forming conditions Deformation and damage depend upon a coupled set of evolving internal state variables, eg dislocation density, which in turn is affected by thermally activated and deformation-dependent recrystallisation and recovery A phenomenological description of damage is derived based on the expected physical scaling with temperature, strain and strain rate The resulting equations were implemented in the commercial software ABAQUS via the user-defined subroutine VUMAT for carrying out forming process simulations An experimental programme was designed, and specialised testing facilities developed for calibrating and validating the FE process modelling results A good agreement between the process simulation and the experimental results has been achieved This confirms that the physical dependencies in the constitutive equations are correctly formed, and that the equations and FE model can be calibrated and used for hot stamping of AA6082 panel parts Further, forming process optimisation was carried out using the model to identify the optimal forming parameters for a basic panel part with a circular hole in the middle The study concludes with a discussion of the potential impact of the constitutive model, experimental characterisation and modelling results on AA6082 panel parts manufacture

A review of the development of creep age forming: Experimentation, modelling and applications

Abstract: About twenty years ago, the process of Creep Age Forming (CAF) was invented, and since then has been developed for the manufacture of heat treatable aluminium alloy panel components particularly, it has been successfully used for aircraft wing panels. Significant research work has been carried out in recent years and process applications have been expanded. This paper contains a review of recent research and development of this novel forming process. It covers process applications in the aircraft industry and scientific research, including the development of forming tools, experimental studies, materials and process modelling and springback prediction. Some potential future applications and challenges for deeper understanding of this novel process are also discussed.

Coverage control for mobile sensing networks

Abstract: This paper presents control and coordination algorithms for groups of vehicles. The focus is on autonomous vehicle networks performing distributed sensing tasks where each vehicle plays the role of a mobile tunable sensor. The paper proposes gradient descent algorithms for a class of utility functions which encode optimal coverage and sensing policies. The resulting closed-loop behavior is adaptive, distributed, asynchronous, and verifiably correct.

Emerging materials and processes for thermal barrier systems

Abstract: Thermal barrier systems have been the subject of vigorous research and development activities over the past few years, driven by the demands for enhanced reliability and substantially higher operating temperatures envisaged for the next generations of gas turbine engines. The menu of candidate materials and architectures has expanded considerably, including numerous concepts based on zirconia as well as radically different materials, multilayers and modulated distributions of porosity and chemical composition. Advances in deposition processes enable increased flexibility for tailoring composition and microstructure to local requirements within the coating system, e.g. for thermal insulation, control of interdiffusion, enhanced resistance against environmental degradation and condition monitoring. Many challenges remain but healthy and growing collaborations between the science and technology communities bode well for future progress in this area.