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Montigny-lès-Metz, France

Niakan F.,INSA Lyon | Vahdani B.,Islamic Azad University at Qazvin | Mohammadi M.,LCFC
Engineering Optimization | Year: 2014

This article proposes a multi-objective mixed-integer model to optimize the location of hubs within a hub network design problem under uncertainty. The considered objectives include minimizing the maximum accumulated travel time, minimizing the total costs including transportation, fuel consumption and greenhouse emissions costs, and finally maximizing the minimum service reliability. In the proposed model, it is assumed that for connecting two nodes, there are several types of arc in which their capacity, transportation mode, travel time, and transportation and construction costs are different. Moreover, in this model, determining the capacity of the hubs is part of the decision-making procedure and balancing requirements are imposed on the network. To solve the model, a hybrid solution approach is utilized based on inexact programming, interval-valued fuzzy programming and rough interval programming. Furthermore, a hybrid multi-objective metaheuristic algorithm, namely multi-objective invasive weed optimization (MOIWO), is developed for the given problem. Finally, various computational experiments are carried out to assess the proposed model and solution approaches. © 2014 Taylor & Francis Source

Qureshi A.J.,LCFC | Dantan J.-Y.,LCFC | Bruyere J.,University Claude Bernard Lyon 1 | Bigot R.,LCFC
Engineering Applications of Artificial Intelligence | Year: 2010

Embodiment design is an important phase of the design process where the initial design parameters and their feasible solution spaces with design configurations are decided for the design problem. This article presents a new approach of embodiment design space exploration of the product based on set based design with integration of robustness for the mechanical systems. The approach presented addresses the initial design phase of the mechanical systems design and provides a three step approach based on a formal expression syntax, transformation and evaluation engine and a computational algorithm for performing a domain search for sets of robust solutions for the product designs by taking into the account the variations and uncertainties related to the manufacturing process and material. The approach is based on the design domain exploration and reduction techniques. This is achieved by the utilization and integration of existential and universal quantifiers from the quantifier constraint satisfaction problem (QCSP) for the expression of the parameters and variables related to the product design and robustness. The quantifier notion has been used to develop the consistency check for the existence of a design solution and existence of a robust design solution. In order to compute the developed quantifier approach, an algorithm based on the transformation of the quantifier with interval arithmetic has also been developed. In order to demonstrate the capability of the developed approach, this article includes three examples of mechanical systems from earlier research works that apply the quantifier model and the resolution algorithm to successfully explore the design domain for robust solutions while taking into account different types of variations such as variations in mechanical/material properties, manufacturing variations or variations in geometric dimensions which may be of continuous or discrete type. © 2010 Elsevier Ltd. All rights reserved. Source

Ullah Butt S.,LCFC | Antoine J.-F.,LCFC | Martin P.,LCFC
Mechanics and Industry | Year: 2012

Dimensional errors of the parts from a part family cause the initial misplacement of the workpiece on the fixture affecting the final product quality. Even if the part is positioned correctly, the external machining forces and clamping load cause the part to deviate from its position. This deviation depends on the external load and the fixture stiffness. In this article, a comprehensive analytical model of a 3-2-1 fixturing system is proposed, consisting of a kinematic and a mechanical part. The kinematic model relocates the initially misplaced workpiece in the machine reference through the axial advancements of six locators taking all the fixturing elements to be rigid. The repositioned part then shifts again from the corrected position due to the deformation of fixturing elements under clamping and machining forces. The mechanical model calculates this displacement of the part considering the locators and clamps to be elastic. The rigid cuboid baseplate, used to precisely relocate the workpiece, is also considered elastic at the interface with the locators. Using small displacement hypothesis with zero friction at the contact points, Lagrangian formulation enables us to calculate the rigid body displacement of the workpiece, deformation of each locator, as well as the stiffness matrix and mechanical behavior of the fixturing system. This displacement of the workpiece is then finally compensated by the advancement of the six axial locators calculated through the kinematic model. © 2012 AFM, EDP Sciences. Source

Wang J.,LCFC | Wang J.,Shanghai JiaoTong University | Langlois L.,LCFC | Rafiq M.,LCFC | And 2 more authors.
Key Engineering Materials | Year: 2013

The presented work is dedicated to studying the forgeability of bimaterial cladded billet. Hot upsetting tests of cylindrical low carbon steel (C15) billets weld cladded (MIG) by stainless steel (SS316L) are experimentally and numerically studied. Upsetting tests with different upsetting ratios are performed in different tribology conditions at 1050°C which is within the better forgeability temperature range of both substrate and cladding materials. Slab model and finite-element simulation are conducted to parametrically study the potential forgeability of the bimaterial cladded billet. The viscoplastic law is adopted to model the friction at the die/billet interface. The friction condition at the die/billet interface has a great impact on the final material distribution, forging effort and cracking occurrence. With Latham and Cockcroft Criterion, the possibility and potential position of cracks could be predicted. Copyright © 2013 Trans Tech Publications Ltd. Source

Wang J.,LCFC | Wang J.,Shanghai JiaoTong University | Langlois L.,LCFC | Rafiq M.,LCFC | And 2 more authors.
Journal of Materials Processing Technology | Year: 2014

This paper focuses on the hot forging of multi-material cladded work pieces using upsetting tests. The case study corresponds to gas metal arc welding cladding of a SS316L on a mild steel (C15). Experimental tests and simulations using a slab model and the finite element method were performed using different temperatures and die/billet tribological conditions. As a result, a crack mode, specific to clad billets, was observed experimentally and can be predicted by the FE method using a Latham and Cockcroft criterion. The material distribution was well simulated by the FE method; in particular, the effects of the friction at die/work piece interface on the crack occurrence, the material distribution and, to a lesser extent, the forging load are well predicted. However, the latter was underestimated, highlighting the fact that the effect of the dilution associated with the cladding process on the material behavior of the clad layer cannot be neglected. © 2013 Elsevier B.V. Source

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