Papers by Keyword: Behaviour Law

Abstract: The final aim of finite elements modelling is to help in the choice of the cutting parameters and in the comprehension of the involved phenomena. Representing correctly the behaviour of the machined material is hard due to the extreme conditions encountered, although this is a key parameter to develop a realistic model. Four laws are used in this paper to represent the Ti6Al4V. They are all based on the Johnson-Cook law. This study shows that the influence of the behaviour law is high on the chip morphology and on the forces and that the strain softening phenomenon should be taken into account. For the cutting conditions adopted, it is however necessary to add damage properties in the chip to obtain a morphology and a cutting force evolution close to the experimental reference.

Abstract: The school of aerospace of Tsinghua University has started a project to develop new kind of stratospheric balloons for earth observation. These balloons will be designed to stand in the same position during a few days at 20 kilometers of altitude. To reach this goal, the first step is to select adapted materials for the balloon envelope. The materials for stratospheric balloons application should have specific properties adapted to the environment such as mechanical, thermo-optical, and permeability properties. Thus, we have asked a material manufacture company to develop and manufacture a material adapted to our application. In this paper, we will present the first results concerning the mechanical properties of the material. Experimental facilities have been developed to test the mechanical behavior of the materials at room and low temperature. The future development of the project will be to identify behavior law adapted to our material that fits with the experimental results.

Abstract: This paper deals with an industrial three rolls coater. The behaviour law of the elastomer roll cover in different environments is first established in order to be taken into account in the numerical simulation of the process. Cyclic compression tests are performed and compared to the corresponding numerical simulation to precisely determine the viscoelastic parameters. With the identified parameters, a finite element simulation of the process is then performed to evaluate the meniscus stability in real contact conditions. The influence of the determined elastomer behaviour laws on the free surface position is discussed.