نتیجه جستجو - Finite element analysis

ردیف | عنوان | نوع |
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1 |
Effect of CNT additives on the electrical properties of derived nanocomposites (experimentally and numerical investigation)
تأثیر افزودنیهای CNT بر خواص الکتریکی نانوکامپوزیتهای مشتقشده (بررسی تجربی و عددی)-2021 In this work, two simulations models have been developed to study the electrical percolation and the
electrical conductivity of epoxy-based nanocomposite containing Multi-walled Carbon Nanotubes. The
models are based on resistor-model and finite element analysis. The former was evaluated using
MATLAB code and the finite element analysis using DIGIMAT software. The maximum tunneling distance
and its influence on the percolation probability and final electrical conductivity were studied. Electrical
measurements on the samples were conducted for numerical validation. The experimental data showed a
percolation achievement around 2 wt%, which was confirmed in the numerical simulations. This study
provides evidence of the effectiveness of the resistor model and finite element method approach to predict the electrical conductivity of nanocomposites.
Keywords: Polymer-matrix composites (PMCs) | Nanocomposites | Carbon nanotube | Electrical properties | Computational modelling |
مقاله انگلیسی |

2 |
Reliability assessment of measurement accuracy for FBG sensors used in structural tests of the wind turbine blades based on strain transfer laws
ارزیابی قابلیت اطمینان از دقت اندازه گیری سنسورهای FBG مورد استفاده در تست های ساختاری تیغه های توربین بادی بر اساس قوانین انتقال فشار-2020 FBG sensors are often packaged within composites before they are pasted on the blade surface,
and many studies have shown that the materials, fatigue properties, geometric parameters, etc. of
intermediate layer have influences on the measuring accuracy of the FBG sensors. Thus, this
paper established an reliability calculation model based on strain transfer efficiency for the
measuring accuracy of FBG sensors packaged by composites, analyzed the influences of material
properties and geometric parameters of the adhesive layer on the performance of FBG sensors
based on finite element analysis (FEA) method, and then compared the differences of strain
transfer efficiency and reliability of the FBG sensors under different load conditions. The results
show that the bond length and the bond thickness of the adhesive layer have greater influences
on the performance of the FBG sensors compared with other parameters, both the strain transfer
efficiency and the reliability of the FBG sensors will reduce over time under suddenly applied
load and increase with increasing frequency of the alternating load. Keywords: FBG sensors | Reliability assessment | Strain transfer law | Static load | Suddenly applied load | Alternating load |
مقاله انگلیسی |

3 |
Delamination analysis using cohesive zone model: A discussion on traction-separation law and mixed-mode criteria
تجزیه و تحلیل لایه لایه شدن با استفاده از مدل منطقه منسجم: بحث در مورد قانون جداسازی کشش و معیارهای حالت مختلط-2020 A discussion on cohesive zone model formulation for prediction of interlaminar damage in
composite laminates is presented in this paper. The degradation of interlaminar mechanical
properties is analysed from a physical point of view. Firstly, the damage evolution is evaluated
according to the traction-separation law and it is demonstrated that if a linear elastic unloading/
reloading curve is assumed, the softening function must also be linear. Secondly, issues regarding
damage onset and fracture criteria in mixed-mode loading are critically addressed and commented.
A new set of criteria is proposed, and the limitations of existing criteria are discussed. Keywords: Cohesive zone modelling | Fracture mechanics | Finite element analysis (FEA) | Delamination | Interface fracture |
مقاله انگلیسی |

4 |
Mixed mode fracture in power law hardening materials for plane stress
شکستگی حالت مخلوطی در مواد سخت کننده قوی برای فشار هواپیما-2020 The classic nonlinear fracture problem of a fully yielded, mixed mode stationary crack in a power law hardening material for conditions of plane stress under small-scale yielding is reconsidered. It has been determined that two different asym ptotic solutions are required to represent the full range of mixed mode loading. Neither asymptotic solution has the double root of the linear elastic counterpart, i.e., the nonlinear plane stress problem does not have a mixed mode asymptotic solution. The mode II dominant asymptotic solution consists of two terms. The leading term is the pure mode II HRR term, while the sec- ond term is symmetric with an eigenvalue slightly weaker than the HRR eigenvalue. This two-term solution applies to a relatively large range of mixed mode loading. The mode I dominant asymptotic solution also consists of a symmetric and an antisymmetric term with different eigenvalues, and has a limited range of applicability near mode I. The pure mode I HRR term is the symmetric term. Contrary to expected behavior based on energy considerations and experience with higher order solutions, the antisymmetric term has an eigenvalue that is stronger than the HRR eigenvalue. This antisymmetric asymptotic solu- tion, which cannot exist without the presence of the mode I HRR term, depends on two small parameters: the distance from the crack tip, r, and the ratio of mode II to mode I loading, K 2 / K 1 . The interpretation is that this two-term asymptotic solution exists for small r in the limit as K 2 / K 1 approaches zero. An unusual feature of the second term is that it does not exist in the limit as r approaches zero, and therefore from a mathematical point of view this term does not cause the J-integral to be infinite. The asymptotic results are confirmed with full-field finite element analysis by using the J 2 deformation theory of plasticity using a computational domain that covers eleven decades of radial detail. This validates the asymptotic solutions and shows that a two-parameter fracture theory can be used very near mode I and near mode II. The transition from one asymptotic solution to the other, which is demonstrated to occur near mode I, gives rise to a loss of dominance of these two-term asymptotic solutions. The hardening exponent, “n”, plays an important role in the ranges of validity of the two asymptotic solutions. Finally, the asymptotic solutions are shown to agree with solutions from the non-hardening limit, and the comparisons are consistent with those of the full-field results. Keywords: Nonlinear fracture | Higher order asymptotic analysis | Mixed mode fracture | Plane stress | HRR theory |
مقاله انگلیسی |

5 |
AI-Assisted Package Design for Improved Warpage Control of Ultra-Thin Packages
طراحی بسته به کمک هوش مصنوعی برای کنترل بهتر Warpage در بسته های فوق العاده نازک-2020 Package design process has evolved from the early days,
when any design was subjected to vigorous analysis using
Design of Experiments (DOE) methodology to understand
the effect of each parameter and material change, to the
introduction of finite element analysis (FEA) to reduce the
DOE runs or completely eliminate it in some cases. FEA
has proved to be a valuable tool. With the easy accessibility
to computing power and the recent advances in AIalgorithms,
this paper presents the next evolution in
package design – AI-assisted package design. This
framework incorporates both physics-driven and datadriven
approaches to develop accurate and efficient design
solutions. A validated AI-assisted package design
framework is presented here to improve the design of the
distribution of metal lines and layers in the substrate with
the objective of reducing warpage. The framework consists
of three phases – assembling the dataset, building a
surrogate model to link substrate design to warpage and
finally using global optimization routines and the surrogate
model to propose changes to the metal layer density
distribution across the substrate so as to reduce warpage |
مقاله انگلیسی |

6 |
Incorporating domain knowledge into reinforcement learning to expedite welding sequence optimization
تلفیق دانش دامنه ای به یادگیری تقویتی برای تسریع در بهینه سازی توالی پیوند-2020 Welding Sequence Optimization (WSO) is very effective to minimize the structural deformation, however
selecting proper welding sequence leads to a combinatorial optimization problem. State-of-the-art algorithms
could take more than one week to compute the best sequence for an assembly of eight weld beads which is
unrealistic for the early stages of Product Delivery Process (PDP). In this article, we develop and implement
a novel Reinforcement Q-learning algorithm for WSO where structural deformation is used to compute
reward function. We utilize a thermo-mechanical Finite Element Analysis (FEA) to predict deformation.
The exploration–exploitation dilemma has been tackled by domain knowledge driven ????-greedy algorithm
into Q-RL which helps to expedite the WSO and we call this novel algorithm as DKQRL. We run welding
simulation experiment using well-known Simufact® software on a typical widely used mounting bracket which
contains eight welding beads. DKQRL allows the reduction of structural deformation up to ∼71% and it
substantially speeds up the computational time over Modified Lowest Cost Search (MLCS), Genetic Algorithm
(GA), exhaustive search, and standard RL algorithm. Results of welding simulation demonstrate a reasonable
agreement with real experiment in terms of structural deformation. Keywords: Welding sequence optimization | FEA based welding simulation | Reinforcement learning | Structural deformation | Residual stress | Artificial intelligence | Machine learning |
مقاله انگلیسی |

7 |
Parametric modeling and structure verification of asphalt pavement based on BIM-ABAQUS
مدل سازی پارامتری و تأیید ساختار روکش آسفالت بر اساس BIM-ABAQUS-2020 As a result of progressive use of BIM in effective collaboration and sophisticated data management, the amount
of diverse project information is rapidly increased, thus its appearance directly led to revolutionary change in
intelligent engineering and production mode. However, it has not been quite advanced in supporting road engineering,
especially in conducting a structural calculation for asphalt pavement. Relying on the capabilities of
BIM and finite element modeling software ABAQUS, this paper proposed a data conversion interface that can not
only present three-dimensional visual modeling but also conduct structural calculation for asphalt pavement. A
3D visualization modeling of asphalt pavement was firstly carried out through Revit modeling software.
Afterward, the generated model file (.RVT) was imported into the transferring software YJK, and the model was
transformed into a file named INP by the transferring software. Thus, the generated model file (.INP) was
analyzed by the software ABAQUS. This study effectively strengthened the BIM with structural analysis capability
by developing a conversion interface based on BIM-ABAQUS. The framework provided a supporting
platform for the integration of BIM-based highway route design and pavement structural analysis in pavement
engineering. Keywords: Asphalt pavement | Revit 3D model | Data conversion interface | Finite element analysis | Structure calculatio |
مقاله انگلیسی |

8 |
Ontology-based approach for the provision of simulation knowledge acquired by Data and Text Mining processes
رویکرد مبتنی بر هستی شناسی برای ارائه دانش شبیه سازی به دست آمده توسط فرآیندهای داده و متن کاوی-2019 Numerical simulation techniques such as Finite Element Analyses are essential in todays engineering design
practices. However, comprehensive knowledge is required for the setup of reliable simulations to verify strength
and further product properties. Due to limited capacities, design-accompanying simulations are performed too
rarely by experienced simulation engineers. Therefore, product models are not sufficiently verified or the simulations
lead to wrong design decisions, if they are applied by less experienced users. This results in belated
redesigns of already detailed product models and to highly cost- and time-intensive iterations in product development.
Thus, in order to support less experienced simulation users in setting up reliable Finite Element Analyses, a
novel ontology-based approach is presented. The knowledge management tools developed on the basis of this
approach allow an automated acquisition and target-oriented provision of necessary simulation knowledge. This
knowledge is acquired from existing simulation models and text-based documentations from previous product
developments by Text and Data Mining. By offering support to less experienced simulation users, the presented
approach may finally lead to a more efficient and extensive application of reliable FEA in product development Keywords: Knowledge-based engineering | Simulation, Finite Element Analysis | Ontology-based knowledge representation | Text Mining | Data Mining |
مقاله انگلیسی |

9 |
Prediction of displacement in the equine third metacarpal bone using a neural network prediction algorithm
پیش بینی جابجایی در استخوان metacarpal سوم اسب با استفاده از الگوریتم پیش بینی شبکه عصبی-2019 Bone is a nonlinear, inhomogeneous and anisotropic material. To predict the behavior of
bones expert systems are employed to reduce the computational cost and to enhance the
accuracy of simulations. In this study, an artificial neural network (ANN) was used for the
prediction of displacement in long bones followed by ex-vivo experiments. Three hydrated
third metacarpal bones (MC3) from 3 thoroughbred horses were used in the experiments. A
set of strain gauges were distributed around the midshaft of the bones. These bones were
then loaded in compression in an MTS machine. The recordings of strains, load, Load
exposure time, and displacement were used as ANN input parameters. The ANN which was
trained using 3,250 experimental data points from two bones predicted the displacement of
the third bone (R2 ≥ 0.98). It was suggested that the ANN should be trained using noisy data
points. The proposed modification in the training algorithm makes the ANN very robust
against noisy inputs measurements. The performance of the ANN was evaluated in response
to changes in the number of input data points and then by assuming a lack of strain
data. A
finite element analysis (FEA) was conducted to replicate one cycle of force-displacement
experimental data (to gain the same accuracy produced by the ANN). The comparison
of FEA and ANN displacement predictions indicates that the ANN produced a satisfactory
outcome within a couple of seconds, while FEA required more than 160 times as long to solve
the same model (CPU time: 5 h and 30 min). Keywords: Artificial neural network (ANN) | Displacement prediction | Finite element analysis (FEA) | Expert system | Long bones | Equine third metacarpal bone (MC3) |
مقاله انگلیسی |

10 |
خمیدگی پوسته های استوانه ای کامپوزیتی با برش های دایره ای: اعتبار سنجی تجربی
سال انتشار: 2019 - تعداد صفحات فایل pdf انگلیسی: 17 - تعداد صفحات فایل doc فارسی: 40 یک مطالعه تجربی بر روی پوستههای استوانهای گرافیت اپوکسی سخت نشده با بریدگی تحت بار خمشی ارائه شده است. دو سیلندر تست شدند: یک سیلندر چند لایه کلاسیک با سختی ثابت و یک سیلندر فیبر دار با سختی متغیر در جهت محیطی. هر دو سیلندر تا زمان ریزش در کنترل جابجایی مورد آزمایش قرار گرفتند. پراکندگیها و کرنشها توسط سنسورهای جابجایی، کرنش سنجها و دو سیستم همبستگی تصویر دیجیتال اندازهگیری شدند. تحلیل دادههای آزمایش نشان میدهد که بیشترین ناحیه تحت فشار لبههای بریدگی هاست که در آن جابجاییهای محلی کرنشهای فشاری بزرگ ایجاد میکنند. دادههای تجربی با نتایج تحلیل آسیب پیشرونده بهدست آمده با تحلیل المان محدود که شامل نقصهای هندسی اندازهگیری شده بود، مقایسه شدند. این تحقیق به دانش سازههای کامپوزیتی با سختی متغیر و کاربرد آنها در بدنه هواپیما کمک میکند. |
مقاله ترجمه شده |