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Due to environmental and ecological responsibility, enterprises are trying to reuse, remanufacture and recycle used products to reduce the negative impact on the environment. Reverse logistics is one of essential elements to implement such sustainable supply chain system. This paper proposes methodologies of simulation modeling and analysis of supply chain systems with reverse logistics flows. This...
The Roll-Ring with a rolling electrical contact is usually utilized in an electrical energy transmission system between two continuous relative rotated equipments, such as the rotation system in radar, tank, space station and so on. As long as the requirement of the transmission power increasing in these years, the rolling electrical characteristic is more and more important for the long-life design...
Considering loss effects on signals in the design of a circuit or a system that works at high frequency will allow to accurately predict a realistic behavior through models that include specific parameters. Losses in dielectric materials and in conductors are simulated in time or frequency domains where different models can better estimate the materials' properties. In the present paper we apply and...
This work evaluates a formulation of the integral equations method to model the field pertubation introduced by a dielectric material in a radiofrequency field typical to a magnetic resonance imaging experiment. The approach incorporates the inhomogeneous body model into the Green's function. The accuracy of the Neumann series expansion is validated against the full numerical solution for different...
Abstract An analytical model of circular contact spots was used in conjunction with numerical methods to estimate the impact electro-migration has on separable power contacts. A single spot model was developed using relative variables to estimate the rate of degradation. The single spot model was generalized to include variations in spot size and change in contact voltage and subsequently used to...
This paper demonstrates relevant physics and provides recommendations regarding thin sheet absorber material applications in enclosures of electronic circuitry. Sheet absorbers placed on the walls of an enclosure are studied herein both experimentally and through the full-wave numerical simulations. In practical applications, the applied absorbing patches need to be selected in terms of proper material...
In this paper, the mould for producing high conductivity aluminum alloy used in electronic packaging has been designed. The three-dimension model is established and extrusion process is simulated by the software DEFORM-3DTM. The paper researches the distribution of the stress and strain under different extrusion velocities and temperature. The numerical simulation results show that the optimum temperature...
ANSYS/LS-DYNA is employed to propose a finite element model of typical shaped charge jet generator and target structure. This model is calculated with the method of ALE algorithm and multi-material fluid-solid coupling. Results of numerical simulation for shaped charge jet penetrating into target are given, and a common method for numerical simulation for this kind of problem comes in to being.
Based on Held's critical initiation criterion of high speed fragment impacting the bare charge, the model for calculating critical initiation speed was proposed for the shelled explosive, the LS-DYNA method was used to simulate the initiation process of shelled explosive impacted by fragment. The results show that, the error of numerical simulation and theoretical calculation was very small, which...
Since the energy conservation is a research focus and numerical control machining is prevalent, this study proposed a methodology to predict the energy consumption of a NC machining process based on NC code analyzing and virtual cutting simulation. The energy characterization model was testified for estimating power consumed by a NC machining on a milling center and the max error is 11.3%, which proves...
Charge packet under high electric dc fields has been observed in polyethylene and its formation has been closely associated with ageing and breakdown of the insulating material. To understand the mechanisms several models have been proposed. In this paper, two models originated from completely different approaches have been reviewed. The first model proposed is based on bipolar charge injection together...
Flip chip technology is increasingly prevalent in electronics assembly (3D System in Package), and is mainly used at fine pitch in the manufacture of megapixels large focal plane detectors arrays. To verify the reliability of these assemblies numerical simulations appear as the less expensive method. However, as very large assemblies contain an array of more than one million solder bumps, the repetitive...
Beam elements have played a very important role in modeling mechanical engineering structures. Curved beams are known to be more efficient in transfer of loads than straight beams. The transfer in the curved beam is affected by means of bending, shear and membrane action. This is particularly important in studying initially curved beams. The aim of this project is to improve the use and flexibility...
Plasmoinc structures, in particularly plasmonic nano antennas are very attractive in many applications. From other side numerical simulations of plasmonic structures are very demanding and expensive in terms of memory and CPU time, making the selection of a suitable numerical method for the field computation important. The numerical problems are caused because optical nanostructures based on metal...
Ferroelectric (e.g., PZT), ferromagnetic (e.g., Terfenol-D) and ferroelastic (e.g., shape memory alloy (SMA)) materials offer unique design and control capabilities for a range of present and emerging control applications. However, all of these materials exhibit creep, rate-dependent hysteresis, and constitutive nonlinearities that must be incorporated in model-based control designs to achieve stringent...
In this paper, a measurement method for electrical characterization of different materials (especially for rubber mixture sheets) is proposed. The measurement method is based on a coaxial probe method and uses 3D electromagnetic simulation for determining the electrical parameters of materials. To simplify the measurement process, a numerical algorithm was defined based on the 3D electromagnetic simulation...
New technologies for the fabrication of Multi-Layer-Composites with sensor and actuator functionality were used. The compounds consist of Macro-Fiber-Composites (MFC) embedded in a layer of epoxy adhesive between two aluminum sheets. Forming takes place in an uncured state of the adhesive, so that a relative displacement between the layers is possible. This paper deals with the experimental and numerical...
In order to study how the Blank Holder Force (BHF), Die Radius and Drawbead (with or without) affect the stamping performance, this paper takes the automobile oil pan as the example, simulates the drawing procedure on Dynaform. And then analyzes the FLD (Forming Limit Diagram), Thickness or thinning figure and forming results. Finally, we get the optimal BHF and die radius.
To secure the reliability of lead free solder is a critical problem for microelectronics packaging. The drop test is used to characterize the reliability of the soldered assemblies. Numerical simulation techniques are popularly used for such tests to reduce the cost. A proper working combination of the damage criterion and the numerical simulation to predict fatigue life is still an unsolved problem...
In the paper, we firstly formulate the natural casing packing problem (NCPP) as a double-objective integer programming model, and then propose a two-stage heuristic algorithm for solving NCPP. Numerical results show that our model and algorithm can determine a nearly optimal solution. Finally, we build an extended version of the model to formulate other related problems.
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