Papers by Keyword: ALE

Abstract: Semiconductor industry periodically goes through major transitions in the architectures and materials. The previous such transition was the Logic transition to FinFET and NAND transition to 3DNAND that revolutionized the two devices and accelerated PPAC (power, performance, area, cost) progress. Over the last decade, introduction of EUV lithography has driven the device miniaturization and furthered the cause of PPAC, but with the same architecture. The accelerating technological needs at lower cost point with better power efficiency are driving the current push in fundamental architectural changes and new materials introductions, especially in Logic and DRAM with a transition to 3D structures. This moves the critical etches from traditional RIE to selective isotropic etching. Furthermore, newer materials and requirements of better interfaces in these 3D structures are driving the need for dry selective treatments with good isotropicity and free of damage. This paper will give an overview of the current state of selective dry etch and progress in treatments.

Abstract: This paper presents achievements in the field of the numerical simulation of the fibrere reinforced concrete (FRC) and ultra-high performance fibre reinforced concrete (UHPFRC). The numerical simulations were performed to verify results of two experimental programmes focused on the blast resistance of FRC and UHPFRC. The response of the FRC and UHPFRC slabs to the contact and near-field blast was studied in these two experiments. As the detail behaviour of specimens could not be observed because of the blast load, the numerical models were prepared. The accuracy of the numerical models was evaluated based on the comparison of numerical and experimental results. Different approaches for blast simulation were tested and compared. The results indicate that the various phenomena (e.g. overpressure propagation, stress cumulation, crack propagation and damage extend) can be successfully simulated. However, the comparison of the soffit velocity, measured with the PDV unit and numerical model showed shortcomings of the numerical model. These numerical model inaccuracies are discussed and their reasons presented.

Abstract: This paper demonstrates precious recovery of nickel from physical pre-treated raw palm oil mill fuel ash waste (POMFAW). The acidic leaching extraction (ALE) using sulphuric and hydrochloric acids agents were carried out in a bath stirrer flask. Process parameter effects of acid concentration, solution pH and treatment time were investigated in the nickel recuperation. The highest nickel recovery (96.83%) was found by treatment time of 1 h, pH of 2.5 and hydrochloric acid concentration of 2.0 M. At the acids leaching higher than 2 M, the nickel recovery decreased. Results from acids leaching imply that nickel complex can be formed at substantial percentages within the acid concentration higher than 1 M. The hydrochloric acid provides impressive nickel compared sulphuric acid, and the POMFAW can be proposed as a substitute of non-renewable sources derived nickel for a promising material and the used ALE can be considered as a beneficial technique.

Abstract: Plate is one of the most common structural elements, which appears in a wide range of applications: steel bridges, blast-resistance door, and armored vehicles. In this paper, the behavior of steel plates under blast loading was studied through numerical approaches using LS DYNA and then the results were compared with the experiment results obtained from existing literatures. The study of a clamped square plate exposed to blast loading in three distinct stand-off distances. Three different methods of modeling blast loading were used, namely: empirical blast method, arbitrary Lagrangian Eulerian (ALE) method, and coupling of Lagrangian and Eulerian method. The empirical blast method was deployed by using key card *LOAD_BLAST in LS-DYNA. In ALE method, Langrangian and Eulerian solution were combined in the same model and the fluid-structure interaction (FSI) handled by coupling algorithm. In coupling method, the engineering load blast in LS-DYNA (*LOAD_BLAST_ENHANCED) was coupled with the ALE solver. In terms of central deflection and computational time, the coupling method appeared to be the best method which is very time-effective and showed a good correlation with the experiment data.

Abstract: The free oscillation of liquid droplet is one of the classical questions in science research, liquid drops play important role in a lot of engineering applications. Theory study of droplet oscillation mainly based on the linear method, this method is only adapted to the small-amplitude oscillatory motion of drops. Except the linear method used in this study, numerical method have been successfully applied in simulation of the free oscillation of liquid droplet. In this paper, the finite element method is used to investigate numerically the influence of viscoelasticity on the small-amplitude oscillation of drop of polymer solutions. A spatial discretization is accomplished by the finite element method, the time descretization is carried by the Crank-Nicolson method, and the arbitrary Lagangian-Eulerian (ALE) method is used to track the change of the interface. Numerical results are compared with the ones of linear theory. The behaviors of oscillation are found to depend on the viscosity and the stress relaxation time of viscoelastic fluid, the results of numerical simulation and linear theory are identical.

Abstract: An explicit finite element method which is combined with the Arbitrary Lagrangian-Eulerian (ALE) algorithm is applied to forecast slamming loads during the structure entries into the water. By adjusting the contact parameter, the result of slamming force is improved and this result is compared with the corresponding experimental values to verify the numerical prediction method of slamming loads. By simulating the wedge into the water at a constant speed and evenly variable speed, the effect of the impact velocity on local slamming pressure and global slamming force is studied.

Abstract: Fluid-Structure Interaction engages with complex geometry especially in biomechanical problem. In order to solve critical case studies such as cardiovascular diseases, we need the structure to be flexible and interact with the surrounding fluids. Thus, to simulate such systems, we have to consider both fluid and structure two-way interactions. An extra attention is needed to develop FSI algorithm in biomechanic problem, namely the algorithm to solve the governing equations, the coupling between the fluid and structural parameter and finally the algorithm for solving the grid connectivity. In this article, we will review essential works that have been done in FSI for biomechanic. Works on Navier–Stokes equations as the basis of the fluid solver and the equation of motion together with the finite element methods for the structure solver are thoroughly discussed. Important issues on the interface between structure and fluid solvers, discretised via Arbitrary Lagrangian–Eulerian grid are also pointed out. The aim is to provide a crystal clear understanding on how to develop an efficient algorithm to solve biomechanical Fluid-Structure Interaction problems in a matrix based programming platform.

Abstract: Scar formation in fine blanking was investigated by means of a particularly developed fine blanking tool and experimental evidence about significant the process parameters chamfer size of the blanking tools, V-Ring usage and clearance is given. Furthermore, a special purpose Finite Element code using the Arbitrary-Lagrange-Eulerian method with a process specific mesh generation is demonstrated and used for the determination of relevant parameters for prediction crack formation in 3D fine blanking simulations. The simulations shown, that a commonly used description of fracture strain as a function of stress and deformation state is not sufficient. In order to simulate scar occurrence on the blanking surface, the significant increase of fracture strain due to temperature rise because of plastic heat generation has to be taken into account. A possible way of measuring the temperature effect was shown in torsion tests at different initial temperature levels.

Abstract: The threat of terrorism has led to increased awareness about protecting properties from damage in terrorist attacks. With the rapid growth of the computer industry and progress in the field of finite-element analysis, evaluations of conventional weapons focus more on simulations than on experiments. There are many approaches to simulate blast and impact. These include Eulerian, Lagrangian, multi-material arbitrary Lagrangian-Eulerian (MM-ALE), and the meshless approach of smooth particle hydrodynamics (SPH) methods. Each method has distinct advantages. In this study, finite-element analysis was applied to simulate a 1 kg trinitrotoluene (TNT) blast in front of a 20-mm-thick steel plate. Three different approaches were simulated: Eulerian, MM-ALE, and SPH. Each method gave different results for the von Mises stress distribution, peak pressure, and displacement of the steel plate. A comparison of the three results implies that using one of these three approaches may generate a significant blast simulation.

Abstract: Although still having certain limitations, the numerical simulation technology has been increasingly applied to aid in optimizing the aluminum extrusion process and die design. In the present research, numerical simulations of the profiles extrusion process were performed, using the Finite Volume Method (FVM) and Finite Element Method (FEM) to make use of the individual merits of the Euler approach and Lagrange approach, respectively. The application of the simulation technology to produce large, complex profiles has, however, been quite limited. In order to solve the limited, numerical simulation of aluminum profiles with large and complicated cross-section in extrusion process was achieved using Arbitrary Lagrangian-Eulerian (ALE) approach, and non-uniform velocities at the die exit, leading to extrudate distortions, were predicted. Extrusion experiments proved that the die with the optimized design could circumvent the distortion problem. The numerical simulation technology can indeed be effectively used to reduce the number of die trials and offer the potential to realize zero die trial.