3D Finite Element Modelling of Cutting Forces in Drilling Fibre Metal Laminates and Experimental Hole Quality Analysis

Machining Glass fibre aluminium reinforced epoxy (GLARE) is cumbersome due to distinctively different mechanical and thermal properties of its constituents, which makes it challenging to achieve damage-free holes with the acceptable surface quality. The proposed work focuses on the study of the machinability of thin (~2.5 mm) GLARE laminate. Drilling trials were conducted to analyse the effect of feed rate and spindle speed on the cutting forces and hole quality. The resulting hole quality metrics (surface roughness, hole size, circularity error, burr formation and delamination) were assessed using surface profilometry and optical scanning techniques. A three dimensional (3D) finite-element (FE) model of drilling GLARE laminate was also developed using ABAQUS/Explicit to help understand the mechanism of drilling GLARE. The homogenised ply-level response of GLARE laminate was considered in the FE model to predict cutting forces in the drilling process

Effect of the Converging Pipe on the Performance of a Lucid Spherical Rotor

Lucid spherical rotor is a cross-\ufb02ow rotor developed to be installed within a pipeline. The purpose of installing this type of rotor is to collect excess energy available in gravity-fed water pipelines. In order to enhance the ef\ufb01ciency of the rotor which is installed in a channel, this paper aims to study the performance of Lucid spherical rotor with converging pipe. Numerical investigations were carried out to analyze the effect of the converging pipe on the performance of the rotor. Numerical simulations have been carried out using the unsteady Reynolds-averaged Navier\u2013Stokes equations in conjunction with the realizable k 12\u3b5 turbulence model. The validation of the numerical method with anterior published studies has been carried out. The hydrodynamic characteristics of the \ufb02ow around therotor with and without converging pipe have been analyzed and discussed. Numerical results indicated that the converging pipe increases the performance of the Lucid spherical rotor

Distribution of the alien Tubificid worm Branchiura sowerbyi (Beddard, 1892) in Morocco

The tubificid worm Branchiura sowerbyi Beddard, 1892 is one of the most successful invasive freshwater oligochaetes worldwide. In the Maghreb region, this species was known only from two localities in Morocco and from one locality in Libya. This paper presents novel information about the current distribution and presence of this invasive species in Morocco, and provides guidance on further areas of research regarding invasive oligochaetes in North African

On the turning modeling and simulation:2D and 3D FEM approaches

For qualitative prediction of chip morphology and quantitative prediction of burr size, 2D and 3D finite element (FE) based turning models have been developed in this paper. Coupled temperature-displacement machining simulations exploiting the capabilities of Abaqus® with a particular industrial turning insert and a newly proposed geometrical version of this insert have been performed. Limitations of 2D models in defining the chip morphologies and surface topologies have been discussed. The phenomenological findings on the Poisson burr (Side burr) formation using 3D cutting models have been highlighted. Bespoke geometry of the turning insert has been found helpful in reducing the Poisson burr formation, as it reduces the contact pressures at the edges of tool rake face-workpiece interface. Lower contact pressures serve to decrease the material flow towards workpiece edges (out of plane deformation). In contrast, higher contact pressures at tool rake face-workpiece interface lead to more material flow towards workpiece edges resulting in longer burr. Simulation results of chip morphologies and cutting forces for turning an aluminum alloy A2024-T351 have been compared with the experimental ones. Finally, it has been concluded that the newly proposed geometry of the insert not only decreases the burr but also helpful in lessening the magnitude of tool-workpiece initial impact

Numerical and experimental analyses of woven composite reinforcement forming using a hypoelastic behaviour. Application to the double dome benchmark

Continuous textile reinforcements hold crucial role when composites are employed as load bearing components. Numerical simulations of the composite forming processes are essential in the design phase of the composite structures. The continuous approach predicts the mechanical characteristics of woven composite fabrics during forming which considers the fibrous materials as a continuum in average at macroscopic scale. An algorithm based on a hypoelastic behaviour is proposed for the simulation of composite reinforcement forming processes. It is shown here that using hypoelastic law with an objective derivative based on the warp and weft fibre rotation tensors can correctly trace the specific behaviour of the woven materials. A number of elementary tests validate the numerical output with theoretical results and the de facto standard in-plane shear test of picture frame has also been validated numerically. An experimental device for textile composite forming on a double dome has been implemented. This forming case has been defined as an international benchmark of woven composites. The simulations performed with the proposed numerical approach show a good agreement with the experimental results obtained with this double dome device

ON NUMERICAL STRATEGY FOR TOOL WEAR MODELLING DURING AISI 4140 CUTTING

International audienceThe quality of machined products is strongly related to the machining conditions especially the tool wear evolution. The latter is among the most important problems encountered by manufacturers. In fact, the complexity of dealing with tool wear is due to the diversity of its origins (abrasion, diffusion, adhesion…) and the limits of models to predict it.For that, the majority of studies were based on experimental works to find laws linking tool wear to several cutting conditions [1, 2]. These estimations are limited to specific cutting conditions far from the industrial context. Some researchers resort to Finite Element (FE) Method to simulate cutting tool wear since it can help to investigate it finely than via experiment’s procedure [3, 4].The aim of this study is to develop a numerical model to simulate cutting tool wear via the FE software ABAQUS®. It is focused on the modeling of the machining of AISI 4140 steel by an uncoated tungsten carbide tool in an orthogonal cutting configuration.A multi-part model is developed to simulate tool wear in orthogonal cutting machining of AISI 4140 steel by an uncoated tungsten carbide tool. A new procedure helping to develop tool wear is implemented via Archard Law. The simulation results are validated by experimental tests