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Abstract: Manufacturing of advanced components like aeroengine parts is performed in a global network. Different manufacturers deliver individual components to the engine and even different manufacturing steps for a given component may be performed at different companies. Furthermore, quality is of utmost importance in this context. Simulations are increasingly used to assure the latter. The current paper describes the simulation of a chain of manufacturing processes for an aeroengine component. Different partners have performed the simulations of the different steps using a variety of finite element codes. The results are discussed in the paper and particularly the lessons learned regarding the modelling process. [Copyright &y& Elsevier]

The simulation of a manufacturing process chain with the finite element method requires the selection of an appropriate finite element solver, element type and mesh density for each process of the chain. When the simulation results of one step are needed in a subsequent one, they have to be interpolated and transferred to another model. This paper presents an in-core grid index that can be created on a mesh represented by a list of nodes/elements. Finite element data can thus be transferred across different models in a process chain by mapping nodes or elements in indexed meshes. For each nodal or integration point of the target mesh, the index on the source mesh is searched for a specific node or element satisfying certain conditions, based on the mapping method. The underlying space of an indexed mesh is decomposed into a grid of variable-sized cells. The index allows local searches to be performed in a small subset of the cells, instead of linear searches in the entire mesh which are computationally expensive. This work focuses on the implementation and computational efficiency of indexing, searching and mapping. An experimental evaluation on medium-sized meshes suggests that the combination of index creation and mapping using the index is much faster than mapping through sequential searches. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this paper is to develop and manufacture a thermoelectric structure operating in Peltier mode with non-standard materials, using a Finite Element Model. Thus, both the reliability of the Finite Element Model and the correct development and design of the new thermoelectric structure are ascertained, achieving a dual goal of our research group. This work provides a very good correlation between simulated and experimental results, and corroborates that the material's performance has a decisive influence on the thermoelectric properties of the structure in the temperature range of study considered. [Copyright &y& Elsevier]

Abstract: A new rotary forming process used to thicken the rim of a disc-like part was proposed. The paper details the results, design and manufacture of the corresponding apparatus. The center point of a ring roller moves around the axis of a stationary work-piece in a plane spiral locus, like a rounding hula hoop. Thereby, the rim of stationary work-piece is rolled and thickened. A design rule for the rotary thickening process of the disc-like part was proposed, and a formula for calculating the feeding force of the roller was deduced. Both the design rule and the formula were verified by the results of experiment and finite element simulation. The forming and flow law during the thickening process were also illustrated. [Copyright &y& Elsevier]

Abstract: At present two packages for IGBT devices are available for applications in the MW power range: the bonded power module and the press-pack housing. Power modules have been object of extensive research including their thermo-mechanical characterisation under variable operating conditions and the analysis of their failure mechanisms. These aspects have been critical to improve the manufacturing process, increase reliability and provide lifetime estimations. The press-pack package eliminates bonding wires and solder layers, and is claimed to offer improved power cycling lifetime. However, the knowledge on press-pack devices is much less mature with only limited data published in literature related to their thermo-mechanical behaviour. This paper presents results of FEM simulations on a full 3D model of a press pack IGBT under power-cycling conditions and during the clamping process. [Copyright &y& Elsevier]

Abstract: A Finite Element Data Exchange System (FEDES) is developed to transfer and map finite element analysis (FEA) data between different FE solvers and meshes. Six commercial FE codes (ABAQUS, ANSYS, DEFORM, MSC.MARC, MORFEO and VULCAN) are incorporated in FEDES. Four mapping techniques are developed and embedded in FEDES which allow the data mapping between meshes with different element types and densities. The algorithms of the mapping techniques are described and compared for 2D and 3D models. The design and capabilities of FEDES are also described. Results from the data transfer and mapping between different FE simulations are presented and discussed. Two manufacturing chains are simulated using FEDES in this paper. The first manufacturing chain is simulated on a parallelepiped geometry including casting, forging and heat treatment processes. The second manufacturing chain is simulated on an aero-engine vane component including metal deposition, welding, heat treatment, machining and shot-peening processes. The development of FEDES demonstrates an integrated simulation platform for modelling manufacturing chains of processes using different FE solvers and meshes. [Copyright &y& Elsevier]

Abstract: The downscaling of manufacturing processes leads to a rise in new challenges in process design. Amongst these challenges is a decrease in the limiting drawing ratio observed in micro deep drawing of metal foils. Furthermore, fracture occurs at punch force levels well below those predicted by common equations. In this paper it is proposed that these phenomena can be accounted for by non-uniformities in the flow behavior of the material due the large difference between grain sizes. The localized strains before fracture – as recorded by digital image correlation – of stretch formed aluminum foils are presented and the strain evolution is examined. Evidence to verify the hypothesis is gathered by implementing the observed flow non-uniformities into a finite element simulation and comparing the computed results to the experimental ones. [Copyright &y& Elsevier]

Abstract: The folding of thin shells around localized lines occurs in several situations of engineering interest, such as in buckling induced deformation, as the consequence of crash, in industrial processes like metal forming, in the deployment of folded membranes, in packaging related processes. In this paper an interface element, allowing for displacement and rotation discontinuities, to be placed between two adjacent 4-node Mindlin–Reissner shell finite elements, is developed for a computationally effective simulation of this type of localized deformation. The large displacement and rotation kinematics of the interface element is discussed, arriving at a rigid-rotation free element tangent stiffness matrix. An adaptive dynamic relaxation scheme is proposed for the evolutionary analysis of the quasi-static structural response. To test the element formulation, a simple coupled membrane-bending elastoplastic behavior is assumed. The element is used for the simulation of few examples taken from the literature, where the structural response is characterized by the formation of plastic hinges, exhibiting good accuracy and computational effectiveness. [Copyright &y& Elsevier]

Abstract: Continuous pyramidal three-roll bending process has the simple configuration. However, two planar zones exist near the leading and trailing edges after a conical roll bending. This paper proposes a three-stage process to improve the geometrical quality of a bent cone for providing an alternative process for the manufacture of the crowns of Francis turbines for hydro plants or the towers of wind power plants. The process was simulated under the commercial software LS-DYNA with an explicit scheme and ANSYS with an implicit scheme. The geometrical quality of the bent cone was improved after the final stage of the process. [Copyright &y& Elsevier]

Abstract: This paper presents the application of an innovative method of optimization to the design of an I-shape profile used in a wood–plastic composite (WPC) pallet. The pallet was made via assembling three WPC extruded profiles manufactured in the extrusion process. The middle profile was considered to be I-shaped, a design which known to have a high load bearing capability. However, due to the characteristics of WPC products, a delicate design and thus optimization is highly required. A multi-objective-optimization program of micro-genetic algorithm was developed in Visual Basic environment to accomplish the optimization task. By specifying the dimensional variables of the profile section and applying finite elements analysis on the profile and then using the optimization program, an optimal profile section was obtained. The objective was to withstand the maximum load while yielding the minimum deflection and mass. The optimized design was used to manufacture a die and then the product was produced to validate the design. The comparison of simulations and experimental results indicted that the given design method is reasonably reliable. The final mass of the produced pallet was less than 20kg whereas its strength against bending and distributed smooth restraint loading were greater than 500kg and 2000kg, respectively. [Copyright &y& Elsevier]

Abstract: During the last few years it has become more and more customary for major industries to use FEM simulations during the product creation process. Most of these metal-forming process simulations are based on elastic plastic behaviour of material and use non-deformable tools. For a correct use of FEM simulations in product development stages, it is very important to determine the accuracy of the simulations. For multi-stage processes, it can be more effective not to simulate the total process but only a few stages of the process, with the last stages usually being the most important ones. To start simulations half way the total process calls for information on the semi-finished product. This information is generated by means of measured values in order to decrease the total modeling time and to increase the accuracy. This paper shows a method developed for handling these problems. The method based on a fully automatic measuring device, including a LECO hardness tester. The results of these measurements were used to verify models, including models based on the transformation behaviour of strain-induced martensite. The examples presented are based on products made of a stainless steel called Nanoflex . [Copyright &y& Elsevier]

Abstract: Multi-point stretch forming (MPSF) is a flexible manufacturing technique to form large sheet panels of mild curvature. The traditional fixed shape-stretching die is replaced by a matrix of punch elements, and the sheet metal are stretch-formed over the multi-point stretching die (MPSD) generated by the punch element matrix. In this paper, extensive numerical simulations of the processes for stretching parabolic cylinder, toroidal saddle and sphere parts were carried out by dynamic explicit finite element analysis. The forming results using multi-point die were compared with those of using traditional die. The use of an elastic cushion to suppress dimpling of the part caused by the discrete punch elements was investigated along with a discussion of its influence on part shape accuracy. The effect of the size of punch element and the shape of MPSD on the shape accuracy of formed parts were analyzed. The results may provide useful guidance on determining MPSF parameters and optimizing MPSF manufacture processes. [Copyright &y& Elsevier]

Abstract: This paper presents a 3D simulation system which is employed in order to predict cutting forces and tool deflection during end-milling operation. In order to verify the accuracy of 3D simulation, results (cutting forces and tool deflection) were compared with those based on the theoretical relationships, in terms of agreement with experiments. The results obtained indicate that the simulation is capable of predicting the cutting forces and tool deflection. [Copyright &y& Elsevier]

In this paper, we presented a coupled 3D finite element method model for the simulation of proppant transport in fracture networks and its effects on horizontal well performance. We used a mixture model, which have advantages to deal with two-phase flow containing a dispersed phase like solid particles, to simulate the proppant transport process in fracture networks. Then a tight oil reservoir model was established to evaluate the effect of the proppant distribution on the horizontal well performance. The effects of several factors, such as the proppant physical properties and injection parameters, were analyzed. The calculated results show that, in the fracture network, proppant accumulates at the intersections of cracks. Height of the proppant packed bed in natural fracture was about 30% smaller than that in the main hydraulic fracture, and the communication between hydraulic fractures leads to a larger proppant dune and higher conductivity. Besides, in a tight oil reservoir, the proppant distribution has a significant influence on the well performance. When the reservoir permeability is reduced to 0.05 mD, the productivity index fold of increase calculated including the proppant uneven distribution can be 47.7% larger than that calculated with idealized proppant distribution. Furthermore, the proppant physical properties and injection parameters are found to be correlated with the fracture network conductivity. Based on this analysis, optimum proppant injection conditions can be identified. • Numerical simulation of proppant transport in fracture network was implemented. • Proppant injection and well production processes were coupled, using FEM method. • Proppant distribution has huge influences on well performance in tight reservoirs. • Injection factors and proppant properties was considered for optimal production. [ABSTRACT FROM AUTHOR]