Advanced Materials Research Vol. 856

Abstract: The flexion solicitation induces in a bent beam a non-uniform stress field. The problem becomes more challenging when the material has a complex behavior, because the material may have different response from one area to another according to the local stress state. In the present work, it is considered, a six parameters rheological model to simulate the behavior of an elastoviscoplastic material. The mathematical law of the behavior is established; thereafter one must determine the beam bending curvature which is an essential and capital parameter for the flexion. Indeed, the bending curvature allows knowing the stress field in the beam. In viscoelastic step, the curvature is obtained by an analytical integration. While in the elastoviscoplastic step, two zones of different behaviors coexist which are namely viscoelastic and elastoviscoplastic, then a numerical integration is required. The numerical integration is achieved, and then the stress field is obtained through the beam and over the time.

Abstract: The milling is the most used technology in engineering. The shape of chip is important for its transport and for economical aspect of this technology. The volumetric coefficient of chip represents the shape of chip. The small chip has a lower volumetric coefficient, but the very small chip is not very desired in the machining, because it can damage the machine. The main aim of this contribution was monitoring of chip in the milling process by high-speed camera and consequently the evaluation of this chip by the volumetric coefficient of chip. This coefficient was monitoring in the peripheral up and down milling with the different radial cutting depth.

Abstract: This paper describes the creep deformation behavior of catheter which is made of soft nylon resin and is reinforced with thin stainless wires called braid. In this research, the creep deformation behavior of uniaxial tension generated under two-stage step stress is examined as the most fundamental case that the principal axis of stress is fixed in a space. And the mechanical model, which is composed of a Voigt unit and a single spring element, is proposed for representing the creep deformation behavior. Then, the numerical simulation is carried out, and the validity of this model is verified by comparing the analytical results with the experimental results under two-stage step stress.