Review on the influence of process parameters in incremental sheet forming

Incremental sheet forming (ISF) is a relatively new flexible forming process. ISF has excellent adaptability to conventional milling machines and requires minimum use of complex tooling, dies and forming press, which makes the process cost-effective and easy to automate for various applications. In the past two decades, extensive research on ISF has resulted in significant advances being made in fundamental understanding and development of new processing and tooling solutions. However, ISF has yet to be fully implemented to mainstream high-value manufacturing industries due to a number of technical challenges, all of which are directly related to ISF process parameters. This paper aims to provide a detailed review of the current state-of-the-art of ISF processes in terms of its technological capabilities and specific limitations with discussions on the ISF process parameters and their effects on ISF processes. Particular attention is given to the ISF process parameters on the formability, deformation and failure mechanics, springback and accuracy and surface roughness. This leads to a number of recommendations that are considered essential for future research effort

Investigation of the effect of forming parameters in incremental sheet forming using a micromechanics based damage model

The incremental sheet forming (ISF) process is considered as a feasible solution for forming a variety of small batch and even customised sheet components. The quality of an ISF product is affected by various process parameters, e.g. sheet material, step-down, feed rate, tool diameter and lubricant. To produce an ISF part of sufficient quality and accuracy without defects, optimal parameters of the ISF process should be selected. In the present work, experiments and FE analyses were conducted to evaluate the influence of the main ISF process parameters including the step-down, feed rate and tool diameter on the formability and fracture of two types of pure Ti (grade 1 and 2). The Gurson–Tvergaard-Needleman (GTN) damage constitutive model with consideration of stress triaxiality was developed to predict ductile fracture in the ISF process due to void nucleation, growth and coalescence. It was found that the ISF parameters have varying degrees of effect on the formability and fracture occurrence of the two types of pure Ti, and grade 2 pure Ti sheet is more sensitive than grade 1 Ti sheet to the forming parameters due to low ductility

Thermo-mechanical forming of a large sling shackle

International audienceA 3D finite element analysis has been carried out of the whole manufacturing process of a shackle involving the steps of closed-die forging and de-flashing of the extremity jaws, the open-die forging of the central body, and the ram bending of the crown. Thermal effects related to the transportation from the gas furnace to the mechanical press and from convective/radiative cooling were also taken into consideration. An elastic-plastic law with viscous effects was used to describe the thermo-mechanical behavior of the 34CrNiMo6 low alloy steel used for the shackle. Based on a fully coupled thermo-mechanical approach, the evolution of thermal and mechanical parameters was studied in details and compared with experimental measurements. A good agreement between the predicted and the experimental data for the die load, process energy, and the dimensions of the flash and the shackle was obtained. This study showed that design, optimization, and analysis of parameters for the manufacturing of shackles can be done efficiently with the use of the numerical simulation; such a numerical design could enhance the productivity

Étude des mécanismes de déformation en formage incrémental

International audienceno abstrac

Multi-camera computer vision for large volume inspection: (a) aeronautical parts inspection and (b) incremental forming

International audienceno abstrac