Finite Element Modeling of Additive Manufacturing in Case of Metal Parts

Metal Additive Manufacturing has grown from 3D metal printing; this technology leads to manufacturing parts using various metallic materials.Additive Manufacturing technology uses the same principle of slicing a solid model into multiple layers and creating a tool path for each layer, then uploading this data to the printing machine and building the part up layer by layer following the sliced model data using a heat source (laser, electron beam, electric arc, or ultrasonic energy, etc.) and feedstock (metal powder, wire or thin metal sheet, etc.).The Additive Manufacturing process starts with designing the prototype, continues with printer pre-processing, then with printing the prototype, and finally with post-processing to get the final part, followed by testing. This sequence has to be repeated till achieving the desired prototype. This method costs money and time. In this paper, the Simufact Additive Manufacturing software makes a virtual simulation to save time and money. In this virtual modelling, different types of materials can be used. Different approaches can be tested, such as building orientations with various parameters, changing supporting structures, and cutting and support removal to achieve a usable process, which is free from damaging effects on the first time that goes through the build. This paper deals with three types of metal alloys (TiAl6V4, AlSi10Mg, and 316L). Different types of machines, thermal analysis, mechanical calibration, thermal and thermomechanical calibration, were applied to find the set parameters such as laser power, inherent strains, exposure energy fraction, and volumetric expansion factor

The arab and european digital native media coverage about each other, analysis of media in several countries: Spain, Portugal, France and Lebanon, Iraq, and Saudi Arabia

This dissertation examines Arab and European digital native media coverage of issues related to the Arab world and Europe in 2020, twenty years after the events of 9/11 The thesis analyses media coverage in the two worlds from various formal and content aspects. The main objective is to analyze the image of Arabs in the European media and the image of Europeans in the Arab media. Media agendas, language, hate speech, stereotypical images of the other, as well as the importance of news, sources of information, and actors outside journalism who control their work are some of the categories studied. Methodological triangulation is used, combining literature review, content analysis, and in-depth interviews. We have worked with six digital native media, representing a sample from Europe and the Arab world (Spain, France, Portugal, Saudi Arabia, Lebanon, and Iraq)

Potential Applications of Additive Manufacturing Technologies in the Vehicle Industry

One of the most competitive fields on the planet is the automotive industry. Newmarket and innovative designs regularly arise, necessitating the development of new manufacturing methods to keep up with the automotive industry. Additive manufacturing offers a significant competitive advantage in this industry, serving as a disruptive strategy by increasing production flexibility, reducing product development time, and providing optimal automotive components and bespoke vehicle products on demand. Additive manufacturing on soft assembly tools or specialised tools to make automotive components enhances automotive production. Additive Manufacturing’s freeform capability allows for the design and direct fabrication of optimised automotive components aimed at improving vehicle performance, as well as tailored assembly tools to boost productivity. Another related technological advantage of additive manufacturing is the ability to create lightweight components with the help of generative design algorithms. Furthermore, the time to market for Additive Manufacturing parts has fallen dramatically, allowing mass customisation to become a reality. The strong downward trend in fuel consumption offers new automobile design, performance, and compliance with regulations. Considering the actual example switch from the conventional combustion engine to other motion systems, Additive Manufacturing is a critical enabler technology for modern automobiles. This paper provides an overview of Additive Manufacturing applications in the automobile sector, focusing on the technical and economic benefits of this manufacturing technology

التجربة الأردنية في تطبيق مفهوم الشرطة المجتمعية المعاصرة

هدف المقال التعرف إلى التجربة الأردنية في تطبيق مفهوم الشرطة المجتمعية المعاصرة. تم استخدام المنهج الوصفي التحليلي لتحقيق أهداف الدراسة، وقد أشارت النتائج إلى أن تجربة الشرطة المجتمعية في مديرية الأمن العام في المملكة الأردنية الهاشمية مبنية على توجيهات ملكية سامية ومتابعة مباشرة ومستمرة من قيادة مديرية الأمن العام بناء على الاطلاع على تجارب دولية وإدراك أهمية الشرطة المجتمعية في نجاح إستراتيجية الأمن العام، كما أثبتت الدراسة أن المملكة الأردنية الهاشمية نجحت في تطبيق معاصر ونموذجي للشرطة المجتمعية ويؤكد ذلك المرتبة المميزة التي حققها الأردن في عدد من التقارير الدولية من مؤسسات عريقة ومحايدة والإحصائيات الرسمية الصادرة بخصوص معدل الجريمة ومن أبرز التقارير الدولية التقرير الصادر عن مؤسسة (غالوب) للعام 2021 والتقرير الصادر عن مؤشر السلام العالمي GLOBAL PEACE INDEX للعام 2022 وأوصت الدراسة بتعميم التجربة الأردنية ومقارنتها بتجارب دول عربية شقيقة والخروج بتطوير للحصول على نتائج أفضل. وتعزيز العمل التشاركي مع المجتمع المحلي وتشجيع الباحثين من طلبة الدراسات العليا التوجه للكتابة عن أهمية ودور الشرطة المجتمعية. The article aimed to identify the Jordanian experience in applying the concept of contemporary community police. The descriptive analytical approach was used to achieve the objectives of this study. And continuing from the leadership of the Public Security Directorate based on the knowledge of international experiences and the realization of the importance of community police in the success of the public security strategy. Ancient and impartial, and the official statistics issued regarding the crime rate. Among the most prominent international reports are the report issued by the (Gallup) Foundation for 2021 and the report issued by the Global Peace Index for 2022. The study recommended generalizing the Jordanian experience and comparing it with the experiences of Arab countries and developing development to obtain better results. Enhancing participatory work with the local community and encouraging postgraduate researchers to write about the importance and role of community police

A Coupled SQMOM-CFD Population Balance Framework for Modelling and Simulation of Liquid-liquid Extraction Equipment

The growing computational power enables the establishment of the Population Balance Equation (PBE) to model the steady state and dynamic behavior of multiphase flow unit operations. Accordingly, the twophase flow behavior inside liquid-liquid extraction equipment is characterized by different factors. These factors include: interactions among droplets (breakage and coalescence), different time scales due to the size distribution of the dispersed phase, and micro time scales of the interphase diffusional mass transfer process. As a result of this, the general PBE has no well known analytical solution and therefore robust numerical solution methods with low computational cost are highly admired. In this work, the Sectional Quadrature Method of Moments (SQMOM) (Attarakih, M. M., Drumm, C., Bart, H.-J. (2009). Solution of the population balance equation using the Sectional Quadrature Method of Moments (SQMOM). Chem. Eng. Sci. 64, 742-752) is extended to take into account the continuous flow systems in spatial domain. In this regard, the SQMOM is extended to solve the spatially distributed nonhomogeneous bivariate PBE to model the hydrodynamics and physical/reactive mass transfer behavior of liquid-liquid extraction equipment. Based on the extended SQMOM, two different steady state and dynamic simulation algorithms for hydrodynamics and mass transfer behavior of liquid-liquid extraction equipment are developed and efficiently implemented. At the steady state modeling level, a Spatially-Mixed SQMOM (SM-SQMOM) algorithm is developed and successfully implemented in a onedimensional physical spatial domain. The integral spatial numerical flux is closed using the mean mass droplet diameter based on the One Primary and One Secondary Particle Method (OPOSPM which is the simplest case of the SQMOM). On the other hand the hydrodynamics integral source terms are closed using the analytical Two-Equal Weight Quadrature (TEqWQ). To avoid the numerical solution of the droplet rise velocity, an analytical solution based on the algebraic velocity model is derived for the particular case of unit velocity exponent appearing in the droplet swarm model. In addition to this, the source term due to mass transport is closed using OPOSPM. The resulting system of ordinary differential equations with respect to space is solved using the MATLAB adaptive Runge–Kutta method (ODE45). At the dynamic modeling level, the SQMOM is extended to a one-dimensional physical spatial domain and resolved using the finite volume method. To close the mathematical model, the required quadrature nodes and weights are calculated using the analytical solution based on the Two Unequal Weights Quadrature (TUEWQ) formula. By applying the finite volume method to the spatial domain, a semi-discreet ordinary differential equation system is obtained and solved. Both steady state and dynamic algorithms are extensively validated at analytical, numerical, and experimental levels. At the numerical level, the predictions of both algorithms are validated using the extended fixed pivot technique as implemented in PPBLab software (Attarakih, M., Alzyod, S., Abu-Khader, M., Bart, H.-J. (2012). PPBLAB: A new multivariate population balance environment for particulate system modeling and simulation. Procedia Eng. 42, pp. 144-562). At the experimental validation level, the extended SQMOM is successfully used to model the steady state hydrodynamics and physical and reactive mass transfer behavior of agitated liquid-liquid extraction columns under different operating conditions. In this regard, both models are found efficient and able to follow liquid extraction column behavior during column scale-up, where three column diameters were investigated (DN32, DN80, and DN150). To shed more light on the local interactions among the contacted phases, a reduced coupled PBE and CFD framework is used to model the hydrodynamic behavior of pulsed sieve plate columns. In this regard, OPOSPM is utilized and implemented in FLUENT 18.2 commercial software as a special case of the SQMOM. The dropletdroplet interactions (breakage and coalescence) are taken into account using OPOSPM, while the required information about the velocity field and energy dissipation is calculated by the CFD model. In addition to this, the proposed coupled OPOSPM-CFD framework is extended to include the mass transfer. The proposed framework is numerically tested and the results are compared with the published experimental data. The required breakage and coalescence parameters to perform the 2D-CFD simulation are estimated using PPBLab software, where a 1D-CFD simulation using a multi-sectional gird is performed. A very good agreement is obtained at the experimental and the numerical validation levels

A Coupled SQMOM-CFD Population Balance Framework for Modelling and Simulation of Liquid-liquid Extraction Equipment

The growing computational power enables the establishment of the Population Balance Equation (PBE) to model the steady state and dynamic behavior of multiphase flow unit operations. Accordingly, the twophase flow behavior inside liquid-liquid extraction equipment is characterized by different factors. These factors include: interactions among droplets (breakage and coalescence), different time scales due to the size distribution of the dispersed phase, and micro time scales of the interphase diffusional mass transfer process. As a result of this, the general PBE has no well known analytical solution and therefore robust numerical solution methods with low computational cost are highly admired. In this work, the Sectional Quadrature Method of Moments (SQMOM) (Attarakih, M. M., Drumm, C., Bart, H.-J. (2009). Solution of the population balance equation using the Sectional Quadrature Method of Moments (SQMOM). Chem. Eng. Sci. 64, 742-752) is extended to take into account the continuous flow systems in spatial domain. In this regard, the SQMOM is extended to solve the spatially distributed nonhomogeneous bivariate PBE to model the hydrodynamics and physical/reactive mass transfer behavior of liquid-liquid extraction equipment. Based on the extended SQMOM, two different steady state and dynamic simulation algorithms for hydrodynamics and mass transfer behavior of liquid-liquid extraction equipment are developed and efficiently implemented. At the steady state modeling level, a Spatially-Mixed SQMOM (SM-SQMOM) algorithm is developed and successfully implemented in a onedimensional physical spatial domain. The integral spatial numerical flux is closed using the mean mass droplet diameter based on the One Primary and One Secondary Particle Method (OPOSPM which is the simplest case of the SQMOM). On the other hand the hydrodynamics integral source terms are closed using the analytical Two-Equal Weight Quadrature (TEqWQ). To avoid the numerical solution of the droplet rise velocity, an analytical solution based on the algebraic velocity model is derived for the particular case of unit velocity exponent appearing in the droplet swarm model. In addition to this, the source term due to mass transport is closed using OPOSPM. The resulting system of ordinary differential equations with respect to space is solved using the MATLAB adaptive Runge–Kutta method (ODE45). At the dynamic modeling level, the SQMOM is extended to a one-dimensional physical spatial domain and resolved using the finite volume method. To close the mathematical model, the required quadrature nodes and weights are calculated using the analytical solution based on the Two Unequal Weights Quadrature (TUEWQ) formula. By applying the finite volume method to the spatial domain, a semi-discreet ordinary differential equation system is obtained and solved. Both steady state and dynamic algorithms are extensively validated at analytical, numerical, and experimental levels. At the numerical level, the predictions of both algorithms are validated using the extended fixed pivot technique as implemented in PPBLab software (Attarakih, M., Alzyod, S., Abu-Khader, M., Bart, H.-J. (2012). PPBLAB: A new multivariate population balance environment for particulate system modeling and simulation. Procedia Eng. 42, pp. 144-562). At the experimental validation level, the extended SQMOM is successfully used to model the steady state hydrodynamics and physical and reactive mass transfer behavior of agitated liquid-liquid extraction columns under different operating conditions. In this regard, both models are found efficient and able to follow liquid extraction column behavior during column scale-up, where three column diameters were investigated (DN32, DN80, and DN150). To shed more light on the local interactions among the contacted phases, a reduced coupled PBE and CFD framework is used to model the hydrodynamic behavior of pulsed sieve plate columns. In this regard, OPOSPM is utilized and implemented in FLUENT 18.2 commercial software as a special case of the SQMOM. The dropletdroplet interactions (breakage and coalescence) are taken into account using OPOSPM, while the required information about the velocity field and energy dissipation is calculated by the CFD model. In addition to this, the proposed coupled OPOSPM-CFD framework is extended to include the mass transfer. The proposed framework is numerically tested and the results are compared with the published experimental data. The required breakage and coalescence parameters to perform the 2D-CFD simulation are estimated using PPBLab software, where a 1D-CFD simulation using a multi-sectional gird is performed. A very good agreement is obtained at the experimental and the numerical validation levels

Correlation Between Printing Parameters and Residual Stress in Additive Manufacturing: A Numerical Simulation Approach

Fused Deposition Modeling (FDM) is a widely used 3D printing technology that can create a diverse range of objects. However, achieving the desired mechanical properties of printed parts can be challenging due to various printing parameters. Residual stress is a critical issue in FDM, which can significantly impact the performance of printed parts. In this study, we used Digimat-AM software to conduct numerical simulations and predict residual stress in Acrylonitrile Butadiene Styrene (ABS) material printed using FDM. We varied six printing parameters, including printing temperature, printing speed, and infill percentage, with four values for each parameter. Our results showed that residual stress was positively correlated with printing temperature, printing speed, and infill percentage, and negatively correlated with layer thickness. Bed temperature did not have a significant effect on residual stress. Finally, using a concentric infill pattern produced the lowest residual stress. The methodology used in this study involved conducting numerical simulations with Digimat-AM software, which allowed us to accurately predict residual stress in FDM-printed ABS parts. The simulations were conducted by systematically varying six printing parameters, with four values for each parameter. The resulting data allowed us to identify correlations between residual stress and printing parameters, and to determine the optimal printing conditions for minimizing residual stress. Our findings contribute to the existing literature by providing insight into the relationship between residual stress and printing parameters in FDM. This information is important for designers and manufacturers who wish to optimize their FDM printing processes for improved part performance. Overall, our study highlights the importance of considering residual stress in FDM printing, and provides valuable information for optimizing the printing process to reduce residual stress in ABS parts

Prediction of the influence of printing parameters on the residual stress using numerical simulation

Fused Deposition Modeling is an additive manufacturing technology that is used to create a wide range of parts and applications. Along with its benefits, there are some challenges regarding the printed parts' mechanical properties, which are associated with printing parameters like layer thickness, printing speed, infill density, printing temperature, bed temperature, infill pattern, chamber temperature, and printing orientation. One of the most crucial challenges in additive manufacturing technology is the residual stress, which significantly affects the parts like fatigue life, cracks propagation, distortions, dimensional accuracy, and corrosion resistance. Residual stress is hard to detect in the components and sometimes is costly to investigate. Printing specimens with different parameters costs money and is timeconsuming. In this work, numerical simulation using Digimat-AM software was employed to predict and minimize the residual stress in printed Acrylonitrile Butadiene Styrene material using Fused Deposition Modeling technology. The printing was done by choosing six different printing parameters with three values for each parameter. The results showed a significant positive correlation between residual stress and printing temperature and infill percentage and a negative correlation with layer thickness and printing speed. At the same time, we found no effect of the bed temperature on the residual stress. Finally, the minimum residual stress was obtained with a concentric infill pattern

A meshless Radial Basis Method (RBM) for solving the detailed population balance equation

International audienceThe Radial Basis Method (RBM) is introduced for solving the Population Balance Equation (PBE). In this method, the continuous number density function is approximated by a series of symmetric multiquadric basis functions at selected global collocation points along the internal coordinates. Therefore, the RBM is considered as a meshless method. The RBM is convenient and suitable for complex problems involving nucleation, growth, breakage and aggregation phenomena. The method provides naturally a continuously differentiable, or “smooth”, solution and avoids solving ill-conditioned problems. The numerical solutions are validated analytically and numerically using different case-studies for uniform stirred-tank. For these examples, 20 collocation points were found to be enough to achieve accurate predictions. The RBM ability to predict multimodal distribution functions and moving steep fronts is moreover highlighted. The proposed method proves to be very efficient for solving the detailed PBE in terms of accuracy, stability and CPU time requirements