فهرس المقالات finite element modeling

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  1 - Numerical simulation of multilayer cellular scaffolds with 3D and 1D elements
  Hamid Reza khanaki Sadegh Rahmati Mohammad Nikkhoo Mohammad Haghpanahi Javad Akbari
  10.30495/admt.2020.1905314.1207
  In this paper, an attempt has been made to provide a numerical method for investigating the mechanical properties of multilayer scaffolding. These scaffolds can be used as implants in bone fractures. For this purpose two numerical simulation methods are introduced to pr أکثر

  In this paper, an attempt has been made to provide a numerical method for investigating the mechanical properties of multilayer scaffolding. These scaffolds can be used as implants in bone fractures. For this purpose two numerical simulation methods are introduced to predict the elastic properties of multilayer cell scaffolds. These simulations are based on two models: a 3D model with a volumetric element, and a 1D model with a linear element. To compare the results of these models, three types of two- and three-layer titanium alloy scaffolds have been simulated by the two methods. Also, Young's modulus of the scaffolds has been compared with the experimental conclusions of earlier studies. The results confirm that simulations with 1D models are more cost-effective compared to 3D ones. Additionally, because of the more reliable agreement of Young's modulus results of numerical modeling with the linear element (1.8 to 5 times) compared to the volumetric element (11 to 23 times) compared to the experimental findings, the numerical method with the linear elements can be a reliable tool for studying multilayer scaffoldings. تفاصيل المقالة
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  2 - The Effect of Soccer Ball Impulse on Lower Limbs of the Human Body
  Leila Shahryari Behtash JavidSharifi JavidSharifi Mohammad Ali Samianifar
  Despite the fact that soccer is one of the most popular sports in the world, little attention has been paid to this game scientifically which could otherwise provide a broad range of interesting outcomes. Sport equipment has a significant effect on how a game is played. أکثر

  Despite the fact that soccer is one of the most popular sports in the world, little attention has been paid to this game scientifically which could otherwise provide a broad range of interesting outcomes. Sport equipment has a significant effect on how a game is played. Different features of the soccer ball such as its size, structure, weight and potential incoming pressure also affect the nature and quality of the game. Different models of soccer balls have been developed with the aim of increasing game quality and performance. Many scholars have investigated the displacements during typical soccer games caused by the ball impulse and the feet, but few studies have focused on the interaction between the ball and the feet. The aim of the present study is, thus, to investigate tension development and possible deformations caused by kicking the ball. Players who are well aware of soccer rules and have a little knowledge about soccer-induced injuries easily realize that the impulse of a non-standard ball considering its material, size or weight may severely damage the knees or other body parts. Due to the importance of the issue, to evaluate the impact of the soccer ball on the footballer’s feet, two finite element models of typical soccer balls have been studied with respect to the standard features of the real soccer ball in the three layers of leather, thread and rubber. The first model is proportional to the mass of the standard ball and the second incorporates a mass less than the standard level. Two models of bones are used in the present study: a single layer bone and a two-layer bone with cortical and cancellous tissues. For better understanding of the injuries resulting from the impulse from a non-standard ball, the used finite element software employs mechanic laws of sport biomechanics to provide better understanding of the details using mathematical modeling, computer simulation and experimental measurements. In this regard, this significant point is achieved through modeling the ball impulse to the feet which is quite complex and needs some simplification. As the soccer ball is flexible, most of the force is absorbed by the model’s flexibility. In the other model with a less flexible ball, the force absorbed by the bone is significantly more. تفاصيل المقالة
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  3 - Effect of flower pattern on the curvature of high-strength steel pipe in roll forming
  M. Karimi Firouzjaei H. Moslemi Naeini B. Abbaszadeh M.M. Kasaei
  The geometrical characteristic of products is one of the crucial quality indicators in the cold roll forming process. In this process, an appropriate flower pattern for rolls is vital to achieve the desired geometry and quality for high-strength steel pipes. In this pap أکثر

  The geometrical characteristic of products is one of the crucial quality indicators in the cold roll forming process. In this process, an appropriate flower pattern for rolls is vital to achieve the desired geometry and quality for high-strength steel pipes. In this paper, four different flower patterns, including circular, edge bending, double radius, and reverse bending are designed for the roll forming process of the high-strength steel pipe. Then, the effect of the flower pattern on the curvature distribution of the deformed strip is investigated using finite element analysis. The accuracy of the finite element model is evaluated by performing experimental tests. The results show that forming the strip with the reverse bending flower pattern leads to a more uniform curvature distribution in its cross-section, especially in the edge portion. Thus, this flower pattern design method is recommended for the roll forming process of the high-strength steel pipes. تفاصيل المقالة
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  4 - Finite Element Modeling of Strain Rate and Grain Size Dependency in Nanocrystalline Materials
  Minoo Tabanfard
  Nanocrystalline materials show a higher strain-rate sensitivity in contrast to the conventional coarse-grained materials and a different grain size dependency. To explain these phenomenon, a finite element model is constructed that considers both grain interior and grai أکثر

  Nanocrystalline materials show a higher strain-rate sensitivity in contrast to the conventional coarse-grained materials and a different grain size dependency. To explain these phenomenon, a finite element model is constructed that considers both grain interior and grain boundary deformation of nanocrystalline materials. The model consist of several crystalline cores with different orientations and grain boundary phase. The nonlinear behavior of the nanocrystalline core is implemented by a grain size dependent crystal plasticity. The boundary phase is assumed to have the mechanical properties of quasi-amorphous material. The constitutive equations for both grains interior and boundary phase are implemented into the finite-element software Abaqus. A calibration procedure was used to tune some parameters of the model with the previously published experimental data on the nanocrystalline copper. Then the model is used to predict the material behavior in various strain rates and grain sizes. The stresses obtained from these simulations match well with the experimental data for nanocrystalline copper at different strains and strain rates. Deviation from the Hall-Petch law and inverse Hall-Petch effect are also well illustrated by the model. تفاصيل المقالة
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  5 - Numerical Analysis of Severe Plastic Deformation by High Pressure Torsion
  mohammadreza kaji Ghader Faraji
  High-pressure torsion (HPT) is a metal processing method in which the sample is subjected to a very high plastic shear deformation. This process can produce exceptional levels of grain refinement, and provides a corresponding improvement in mechanical properties. To inv أکثر

  High-pressure torsion (HPT) is a metal processing method in which the sample is subjected to a very high plastic shear deformation. This process can produce exceptional levels of grain refinement, and provides a corresponding improvement in mechanical properties. To investigate the stress and strain distribution due to HPT process finite element simulation were conducted to investigate effective parameters. The simulation results demonstrate that the lowest effective strain obtained in the centers of the disk and the highest at the edges. Also, the mean stress varies linearly from the center of the disk to the edge region. The compressive stresses are higher in the disk centers and lower at the edges. By increasing the friction coefficient and the die angle, mean stress decrease and stress variation along the disc diameters become more homogeneous. Increasing of the pressure load leads to increase the mean stress and its heterogeneity along the disc radius. تفاصيل المقالة
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  6 - Deformation of Al Alloy during Integrated Extrusion and ECAP: A Simulation Research
  Ankit Sahai Shanti S. Sharma Suren N. Dwivedi
  Bulk nanomaterial have several applications in automobile, aerospace, medical and manufacturing applications. These are produced by subjecting materials to severe plastic deformation (SPD) and have widely emerged as a technique for grain refinement in Al, Cu, Ti, Mg all أکثر

  Bulk nanomaterial have several applications in automobile, aerospace, medical and manufacturing applications. These are produced by subjecting materials to severe plastic deformation (SPD) and have widely emerged as a technique for grain refinement in Al, Cu, Ti, Mg alloys with improved mechanical properties. Equal Channel Angular Pressing (ECAP) is one such SPD technique employed to produce bulk ultra-fine grained (UFG) materials by introducing a large amount of shear strain into the materials without changing the billet shape or dimensions. FE (Finite Element) modeling of SPD processes has become an important tool for designing feasible production processes, because of its unique capability to describe the complex geometry and boundary conditions. In this proposed work, integrated SPD processes namely Extrusion + ECAP (Ex-ECAP) is proposed and the specimen is subjected to these processes in the same die set-up. The 3D finite element modeling of Al6061 was performed using metal forming software FORGE. The dies used in both the processes during the simulation of Al6061 billet include a channel angle of 900 and outer corner angle fixed at 160 with simulation performed for different plunger velocities. The simulation results depict the change in equivalent strain in the entire specimen on account of these processes. The evolution of strain at different considered cross-sections is analyzed. Also, the variation in extrusion force and energy are studied for the considered process parameters. The FE simulations greatly help in designing the dies for various experimental conditions to produce bulk nanomaterial. تفاصيل المقالة
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  7 - ارزیابی عملکرد لرزه‌ای سازه‌های فولادی مجهز به مهاربندهای ترکیبی فولاد-آلیاژ حافظه‌دار شکلی
  محمد هوشمند بهزاد رافضی جلیل خلیل علافی
  در این مقاله به بررسی رفتار لرزه‌ای مهاربندهای ترکیبی از جنس فولاد و آلیاژهای حافظه‌دار شکلی پرداخته شده است. جهت بررسی از شش مدل مهاربند ترکیبی با میزان مصرف آلیاژ حافظه‌دار شکلی با معیار طول به ترتیب صفر ، 20 ، 40 ، 60 ، 80 و 100 درصد از طول کل استفاده شده است. ارزیاب أکثر

  در این مقاله به بررسی رفتار لرزه‌ای مهاربندهای ترکیبی از جنس فولاد و آلیاژهای حافظه‌دار شکلی پرداخته شده است. جهت بررسی از شش مدل مهاربند ترکیبی با میزان مصرف آلیاژ حافظه‌دار شکلی با معیار طول به ترتیب صفر ، 20 ، 40 ، 60 ، 80 و 100 درصد از طول کل استفاده شده است. ارزیابی مدل‌ها به کمک تحلیل دینامیکی غیر خطی تحت زلزله السنترو مقیاس شده با شتاب‌های حداکثر 0.6g و 0.9g در نرم افزار ANSYS v11 انجام گرفته است. نتایج مطالعات انجام شده مقادیر طولی بهینه برای درصد مهاربند ترکیبی را مشخص می‌کند بطوریکه می‌توان با استفاده از مقادیر پیشنهادی و طرح ارائه شده، سازه‌هایی بار رفتار لرزه‌ای مناسب و با هزینه ساخت قابل توجیه طراحی و اجرا نمود. تفاصيل المقالة
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  8 - A Roll Wear Prediction Model in Hot Plate Rolling
  امیر نورانی محمود سلیمی
  In this paper, the wear of work roll in hot plate rolling is introduced and the parameters affecting wear mechanisms in hot strip mill are investigated. In addition, different wear mechanisms in hot rolling and the differences between these mechanisms in different stand أکثر

  In this paper, the wear of work roll in hot plate rolling is introduced and the parameters affecting wear mechanisms in hot strip mill are investigated. In addition, different wear mechanisms in hot rolling and the differences between these mechanisms in different stands are explained. Using the finite element method and the rolling equations, a work roll wear model is proposed. Wear is modeled using the resultant pressure distribution along the roll barrel. To obtain the tentative coefficient, summation of wear in each pass schedule is obtained and calibrated via actual wear of samples tested in the Mobarakeh Steel Company. Finally, the theoretical wear values are compared with those of the experiment. The predicted wear profiles are found to be in good agreement with those of the experimental measured values. تفاصيل المقالة