Publication Date: 2025
Acta Mechanica (16196937)
This paper develops a finite element method (FEM) to study the dynamic behavior of two-dimensional (2D) micromorphic thermo-hyperelastic solids with finite deformations. For this purpose, a two-point formulation is derived using energy functions including mechanical, thermal and coupling (due to thermal expansion) between thermal and mechanical parts. The vector–matrix representation of this formulation is also given which can be exploited in the coding procedure of numerical methods. FEM, utilizing the Newton–Raphson and Newmark techniques, has been employed to solve nonlinear time-dependent micromorphic thermo-hyperelastic governing equations. Some test problems are solved to demonstrate the accuracy and reliability of the approach. Furthermore, the influences of internal length parameter, thermal expansion and heat flux on the dynamic behavior of the micromorphic thermo-hyperelastic structures are examined. © The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature 2025.
Publication Date: 2026
Applied Mathematical Modelling (0307904X)153
This paper presents a new variational differential quadrature (VDQ)-transform method for the two-dimensional nonlinear dynamic analysis of hyperelastic structures resting on nonlinear elastic foundations. The developed formulation is established within Hamilton's variational framework using the compressible Neo-Hookean constitutive model, thereby accounting for both material and geometrical nonlinearities under finite deformation. The nonlinear foundation is modeled using an extended three-parameter Winkler-Pasternak formulation, incorporating shear interaction and nonlinear stiffness coupling. A major novelty of the study lies in the tensor-to-matrix transformation, which systematically converts higher-order tensor operations into compact matrix-vector relations for stresses and tangent moduli, ensuring computational efficiency and easy implementability across arbitrarily shaped geometries. Benchmark problems—including a curved beam and Cook's membrane—are provided to validate the proposed approach and to demonstrate its performance. The results highlight that nonlinear foundation parameters substantially modify the transient response and stability limits of hyperelastic structures, emphasizing the significance of combined geometrical and material nonlinearities in advanced flexible systems. © 2025 Elsevier Inc.
Publication Date: 2025
International Journal of Non-Linear Mechanics (00207462)174
The purpose of this article is to introduce a novel finite element (FE) approach for investigating the large deformations of three-dimensional (3D) micromorphic hyperelastic continua that have an arbitrary geometry. The 3D micromorphic hyperelasticity formulation is initially presented in a general form. To facilitate the procedure of coding, the vector-matrix counterparts of the aforementioned relations are also provided, which can be conveniently employed in numerical methods. Afterwards, an FE approach is implemented to investigate the large deformations of micromorphic hyperelastic structures under static loading. This is achieved via the user element (UEL) subroutine utilized by the commercial ABAQUS software. Problems with complex domains can be solved using this FE approach. Solving some test problems, including bending of a beam, Cook's membrane under bending load, a cracked spherical shell under external pressure point load and a cracked cylindrical shell under stretching load, demonstrates the fast convergence rate, simple implementation, accuracy and efficiency of the method. In addition, the influences of internal length and scale-transition parameters and geometrical properties on the finite deformation of considered micromorphic hyperelastic structures are evaluated. © 2025 Elsevier Ltd
Senemar, S.,
Saffari, B.,
Sharifkazemi, M.B.,
Bahari, M.,
Jouyan, N.,
Dehaghani, E.D.,
Yavarian, M. Publication Date: 2013
EXCLI Journal (16112156)12pp. 437-448
Elevated level of plasma homocysteine (Hcy) has been identified as an independent risk factor for coronary artery disease (CAD). Furthermore, numerous studies have documented the influences of a common polymorphism (C677T) of methylenetetrahydrofolate reductase (MTHFR) on homocysteine levels. However the relationship between this mutation and cardiovascular diseases (CVD) has remained as a controversial issue. The present study was undertaken to investigate the relationship between C677T polymorphism of MTHFR gene, plasma total Hcy levels and the number of affected vessels as a criterion for the extent of CAD. MTHFR genotypes and plasma homocysteine (HCY) concentrations were examined in 231 patients and 300 healthy subjects who underwent diagnostic coronary angiography. A multiple linear regression analysis was performed to identify the predictors of Hcy levels whereas logistic regression model was built to determine the association of Hcy quartiles with the risk of CAD adjusted for risk factors. The prevalence of MTHFR genotypes was similar between CAD patients and non-CAD individuals while the geometric mean of Hcy values was significantly higher in patient group (14.13 ± 4.11 μmol/l) than in control group (10.19 ± 3.52 μmol/l) (P < 0.001). Moreover, unlike the MTHFR polymorphism, Hcy concentration increased with increasing number of stenosed vessels and the CAD risk increased about 2 folds in the top two Hcy quartiles (≥ 17.03 and 13.20-17.02 μmol/l) compared with the lowest quartile (≤ 9.92 μmol/l) after controlling for conventional risk factors (P<0.001 for both). Our data suggest that hyperhomocysteinaemia (HHcy) is significantly associated to CAD risk increase as well as to the extent of coronary atherosclerosis.
Publication Date: 2018
Composite Structures (0263-8223)205pp. 69-85
The main objective of the present study is to develop a hexahedral C1 continuous element for the three-dimensional nonlinear free vibration analysis of rectangular nano-plates with circular cutout based on the strain gradient elasticity theory. In the proposed element, in addition to the values of displacement components, the corresponding first, mixed second and mixed third order derivatives are taken into account as nodal values. Since arbitrary-shaped hexahedral elements are considered, spatial derivatives are presented using isoparametric formulation. To derive the nonlinear governing equations, the matrix form of kinetic and strain energies are written based on the three-dimensional strain gradient elasticity theory which can be reduced to the modified strain gradient theory (MSGT) and the modified couple stress theory (MCST). The accuracy and convergence of the numerical results are first investigated. In the parametric study, the nonlinear free vibration response of nano-plate is studied for different length scale parameters, geometrical factors and boundary conditions. © 2018 Elsevier Ltd
Publication Date: 2014
Social Sciences (discontinued) (18185800)9(2)pp. 118-123
In 1928, the Iranian legal system was approached the Western and Roman-Germanic legal system formally, though it was coordinated with Islamic Law in content. There is no separate section under the tide of contract law in Iranian civil code but most of the legal Articles related to the contract law are listed in contracts and obligations from the article 183 onward. Articles 264-300 of civil code of Iran deal with the discharge of obligations. According to article 264, obligations can be discharged in one of the ways including fulfillment of obligation, cancellation by mutual consent, release from the obligation, substitution of different obligation, set off and recoupment and acquisition of the debt. This study, aims to identify the legal system and discharge of contractual obligations in the civil law of Iran. This research study is of library type and uses descriptive methodology. © Medwell Journals, 2014.
Publication Date: 2013
Middle East Journal of Scientific Research (discontinued) (19998147)18(4)pp. 444-450
In 1928, the Iranian legal system was approached the Western and Roman-Germanic legal system formally, though it was coordinated with Islamic Law in content. There is no separate section under the title of contract law in Iranian Civil Code but most of the legal Articles related to the contract law are listed in contracts and obligations from the Article 183 onward. Articles 264 to 300 of Civil Code of Iran deal with the discharge of obligations. According to Article 264, obligations can be discharged in one of the ways including fulfillment of obligation, cancellation by mutual consent, release from the obligation, substitution of different obligation, set off and recoupment and acquisition of the debt. This paper aims to identify the legal system and discharge of contractual obligations in the civil law of Iran. This research study is of library type and uses descriptive methodology. ©IDOSI Publications, 2013.
Publication Date: 2023
Mechanics of Advanced Materials and Structures (15210596)30(24)pp. 5159-5175
A two-stage molecular dynamics (MD)-finite element (FE) modeling method is developed based on the concepts of representative volume element (RVE) and equivalent solid fibers (ESFs) containing functionalized carbon nanotubes (ESFs-fCNTs). First, the influences of nanotubes’ chirality, different percent of functionalization ((Formula presented.)), various functional atoms, and polymers on the tensile and shear properties of the fCNTs inserted into the polymer matrix (fCNTs/polymer) are discovered using MD simulations. Then, using MD information as input data, the effective Young’s modulus of polymeric unit cell strengthened by ESFs-fCNTs (ESFs-fCNTs/polymer) is explored through FE modeling. The ratio of effective Young’s modulus of the unit cell ((Formula presented.)) to Young’s modulus of the polymeric cube ((Formula presented.)) is reported and all findings ((Formula presented.)) are compared to the ESFs-pure CNTs/polymer results as well. It is found that longitudinal Young’s modulus ((Formula presented.)) of nanofillers/polymer RVEs affects remarkably the (Formula presented.) of the ESFs-nanofillers/polymer nanocomposites. The (Formula presented.) decreases by increasing the (Formula presented.) Generally, the reinforcing impact of zigzag nanotubes compared to armchair ones on the (Formula presented.) of polymer RVEs is more considerable. Additionally, FE-based results illustrate that as the volume fraction of ESFs ((Formula presented.)) increases, the (Formula presented.) is enhanced. At a specific (Formula presented.) the reinforcing effect of the ESFs-armchair and zigzag fCNTs is more in favor of polyethylene nanocomposites than that of the polypropylene systems. © 2022 Taylor & Francis Group, LLC.
Publication Date: 2024
India Quarterly (09749284)80(3)pp. 400-420
After the discovery of large oil and gas deposits in Central Asia, the region has become a vital battlefield for major world powers’ competing interests, resulting in a complex geopolitical and energy transportation interaction known as ‘pipeline politics’. After independence, multinational energy companies and global powers contacted the Central Asian Republics. Chinese investment has dominated the region’s energy sector throughout the past decade. India is strategically seeking Central Asia’s energy resources as it becomes more global. This article compares China’s and India’s Central Asian natural gas strategy and identifies research shortcomings. The complex geopolitical landscape is considered while examining their objectives and regional investments. This analysis reveals these methods’ motivations and their effects on the Central Asian Republics and the world. China has an advantage over India in Central Asian pipeline politics, making the region vital to China’s energy security. © 2024 Indian Council of World Affairs (ICWA).
Soft power as one manifestation of power allows countries to gain influence through means such as po-litical values, cultural diplomacy, and foreign policy attitudes. Iraq has become a venue for influential players such as Iran and the US to exert their soft power after 2003. Iran employs shared religious ties with the Shiite population in Iraq, promotes its independent anti-imperialist foreign policy as a value, highlights the shared geography and historical memories between the two countries, and applies other similar elements to enhance its soft power. On the other hand, the United States employs cultural attrac-tions and promotes values such as freedom, democracy, and human rights. The United States presents itself as an idealistic democratic archetype and encourages Iraq to emulate its model in the post-Saddam era. The aim of this chapter is to provide a comparison of soft power status of Iran and the US in the post-Saddam Iraq. © 2024, IGI Global. All rights reserved.
Publication Date: 2014
Mediterranean Journal of Social Sciences (discontinued) (20392117)5(7)pp. 555-561
After the victory of the Islamic Revolution of Iran, scholars and thinkers encountered new scientific conditions, modern political ideas and newly established time and ground, and each, responding to these new upheavals which was the governance and fulfilment of Islamic commandments in all political, social, cultural and economic fields, presented ideas appropriate to their thought constellation. Reza Davari as a Fardidian thinker, following the ideas of the famous German philosopher, Martin Heidegger, criticizes the West philosophically and phenomenologically and knows the only redemptive path for Iranians as leaving the West as an integrated whole and criticizes modernity in a severe way. Contrary to this uncompromising approach to the West, another approach, particularly in the second and third decades of the Islamic Revolution gradually appeared which practiced sympathetic approaches to the West and Abdul Karim Soroush as the forerunner of this approach, tried to pave that path for establishing modernism by an epistemological reading of religion. In the present article, it has been tried to discuss and compare the ideas and thoughts of Davari and Soroush to the West.
Nowadays, in the goods and services market, retaining existing customers is more profitable than attracting new customers. Since latter costs more than the former, having loyal customers is now a major goal for many organizations. Also, with the development of e-businesses, creating this loyalty as e-loyalty is highly important. The aim of this paper is to investigate the influence of each of the Porter's strategy dimensions, including cost leadership, differentiation and focus, on loyalty in the context of e-business. In this regard, a questionnaire was prepared; subsequent to approving the validity of the questionnaire, it was randomly distributed among a random sample of 100 people who were potential and actual users of particular sites in the City of Isfahan. The findings indicate that, although focus strategy is more effective on creating e-loyalty, no significant difference was observed between the two other strategies in having more influence on e-loyalty. © 2016 IEEE.
Publication Date: 2014
Advances in Environmental Biology (19950756)8(13)pp. 517-526
The legal system of Islam, devotion means that some property is dedicated to God and similarly there is a "Caman La trusts" in the legal system. In both legal systems, and maintain the property owner has good intentions for good intentions and good practice and preservation of their wealth for future generations and keep them everlasting but pause and review the implementation of the establishment of these two institutions, each with attributes, constraints manipulation owner of the establishment, the powers of the trustee and the trust in the transfer of ownership or interest, governance, and oversight of endowment and trust funds. Based on the legal rules governing the regulation of the devotion, the devotion is limited and there is no possibility of selling and making money are devoted to interest alone. The comparative trust is essential suggestions are given to change laws which this paper deals with a comparative study of these two entities. © 2014 AENSI Publisher All rights reserved.
Dabestani, R.,
Shahin, A.,
Shirouyehzad, H.,
Saljoughian, M. Publication Date: 2017
Total Quality Management and Business Excellence (14783363)28(3-4)pp. 331-350
The current study aims to prioritise service quality dimensions (SQDs) for hotels through a two-step procedure: firstly, by forming congruent groups of customers based on their level of expectations as well as perceptions of service; and secondly, by prioritising SQDs for each group and analysing the results. To reach that aim, the customers of three four-star hotels were targeted and asked to report on the quality of the service they expected to receive prior to its delivery as well as their feelings towards the service after they received it. Then, using data envelopment analysis we discriminated the majority of customers, those who were satisfied more easily (ordinary customers), from the ones who were harder to please (fastidious customers). Finally, we exploited Technique for Order Preference by Similarity to an Ideal Solution and Shannon Entropy to prioritise SQDs for each group. The approach taken in this paper, which first distinguishes two groups of fastidious from ordinary customers based on their expectations and perceptions, is rather noble. Findings revealed that the two groups do not value different dimensions of service quality in a similar way. The results of this study can provide insightful guidance for the hoteliers to customise their service and exploit their resources more efficiently. © 2015 Taylor & Francis.
Seifouri, F.,
Nia, S.A.M.S.,
Hatami, A.,
Zadeh, S.J.E. Publication Date: 2019
Austral: Brazilian Journal of Strategy and International Relations (22386262)8(15)pp. 88-116
Globalization and social development, as two independent and interactional discourses, have been investigated in this paper using the globalization indicators in two Khatami's and Ahmadinejad's administrations. Thus, the independent variable of globalization, and the dependent variable of the state of social development of Iran are compared in the two periods of 1997-2005 and 2005-2013 considering the different approaches adopted in the two administrations. The research method is comparative. The research hypothesis is that based on valid statistics, both administrations have been on the path to social development, but Khatami's approach was based on global reformism, and Ahmadinejad's approach was based on indigenous and local thoughts. In terms of theoretical foundations, we have used the generalization model of political-social development. According to this model, development priorities are different in countries with different political and social contexts. Social globalization grew as much as 8.86 in the Khatami's administration, and up to 4.89 in Ahmadinejad's administration. Therefore, the administration type is related to the extent of globalization, and globalization has contributed to the growth and development of social development. It also has provided a platform for the continuation of studies of this trend in a different way, regarding the states and the internal environment of the countries. © 2019 Universidade Federal do Rio Grande do Sul.
Publication Date: 2024
Iranian Polymer Journal (10261265)33(12)pp. 1677-1688
This study aims to examine how moisture absorption affects the impact behavior of a recently developed sandwich structure designed for use as a water-resistant system in the marine industry. For this purpose, two types of balsa-cored sandwich systems were manufactured, one with conventional glass fiber-epoxy (GE) skins and the other with novel fiber metal laminates (FML) skins. Subsequently, the specimens were exposed to environmental aging through distilled water immersion for 100 days before impact testing. Low-velocity impact behavior was studied using Charpy tests, while high-velocity impact tests were conducted with a light gas gun. The experimental results showed that FML sandwich systems exhibited significantly better impact characteristics compared to GE systems. Before aging, the Charpy impact strength and high-velocity impact absorbed energy of FML systems were 187% and 49% higher than those of GE ones. Another main finding was the impact properties of the FML systems showed a lower decline due to moisture aging compared to the GE systems, for both low- and high-velocity impacts. The reduction of Charpy impact strength and high-velocity impact absorbed energy due to moisture aging in GE systems with sealed edges was about 15%, and 3%, respectively, and for sealed edges FML systems was less than 12% and 1%, respectively. The results also indicated that the high-velocity impact properties of both sandwich systems studied were not significantly affected by moisture aging. In general, the findings suggest that FML skins significantly enhance both the impact resistance and environmental durability in marine balsa-cored sandwich structures. Graphical abstract: (Figure presented.) © Iran Polymer and Petrochemical Institute 2024.
Hajiaghaei, B.,
Ebrahimi-takamjani, I.,
Kamyab, M.,
Saeedi, H.,
Jalali, M. Publication Date: 2016
Medical Journal Of The Islamic Republic Of Iran (22516840)30(1)
Background: Creating a socket with proper fit is an important factor to ensure the comfort and control of prosthetic devices. Several techniques are commonly used to cast transtibial stumps but their effect on stump shape deformation is not well understood. This study compares the dimensions, circumferences and volumes of the positive casts and also the socket comfort between two casting methods. Our hypothesis was that the casts prepared by air pressure method have less volume and are more comfortable than those prepared by weight bearing method. Methods: Fifteen transtibial unilateral amputees participated in the study. Two weight bearing and air pressure casting methods were utilized for their residual limbs. The diameters and circumferences of various areas of the residual limbs and positive casts were compared. The volumes of two types of casts were measured by a volumeter and compared. Visual Analogue Scale (VAS) was used to measure the sockets fit comfort. Results: Circumferences at 10 and 15 cm below the patella on the casts were significantly smaller in air pressure casting method compared to the weight bearing method (p=0.00 and 0.01 respectively). The volume of the cast in air pressure method was lower than that of the weight bearing method (p=0.006). The amputees found the fit of the sockets prepared by air pressure method more comfortable than the weight bearing sockets (p=0.015). Conclusion: The air pressure casting reduced the circumferences of the distal portion of residual limbs which has more soft tissue and because of its snug fit it provided more comfort for amputees, according to the VAS measurements.
Publication Date: 2021
Mechanics of Advanced Materials and Structures (15210596)28(24)pp. 2531-2550
Reinforced by nanowires (NWs), carbon nanotubes (CNTs) and NW encapsulated CNT (NW@CNT), tensile behavior of various types of Cu-Zr based metallic glass (MG) nanocomposites are studied using molecular dynamics (MD) simulations. It is observed that pure two-toms alloy MG and the one reinforced with bigger CNT demonstrates higher tensile properties than other types of MGs. Further, it is observed that the ultimate strength of reinforced MGs with individual CNTs is slightly higher than that of NW@CNT reinforced analogous. In this case, it is noticed that reinforced three-atoms Cu-Zr MG nanocomposites including Ti atoms demonstrate the highest ultimate strength and strain. © 2020 Taylor & Francis Group, LLC.
Publication Date: 2025
International Journal for Numerical Methods in Engineering (00295981)126(22)
This article presents a comparative study of the computational characteristics of Finite Element Analysis (FEA) and Isogeometric Analysis (IGA) in studying large elastic deformations and large-amplitude vibrations of shell-type structures. A geometrically nonlinear seven-parameter shell model is employed in a Lagrangian description in which the shell deformation is represented in mid-surface. Using a curvilinear coordinate system suitable for various geometries, the kinematic and kinetic of the problem are established, and Hamilton's principle is applied to derive the governing equations. The strain–displacement relationships and consequently, the remaining variational formulations are expressed in a matrix-vector form, allowing for direct implementation in both FEA and IGA. This efficient formulation enables a fair and consistent comparison between the two methods. Several numerical examples are examined, including the well-known static benchmark problems and their corresponding forced vibration analyses. The primary contribution of this article is the demonstration of the computational efficiency of isogeometric analysis in challenging case studies of geometrically nonlinear shells. Additional novel contributions include deriving a unified formulation for seven-parameter FEA and IGA shell models as well as analyzing the large-amplitude free and forced vibrations of shells. © 2025 John Wiley & Sons Ltd.
Publication Date: 2020
Composites Part A: Applied Science and Manufacturing (1359-835X)130
This article investigates electrical conductivity and piezoresistivity of carbon nanotube (CNT)-polymer nanocomposites using an efficient analytical model. The effects of chopped carbon fibers on the electrical conductivity and percolation behavior of multiscale polymer-based nanocomposites containing CNTs are examined at various maximum angular orientations and different polymer matrix barrier heights. The multiscale nanocomposite (MSNC) electrical conductivity and percolation onset are found to be dependent on the carbon fiber and CNT geometry and dispersion. The tunneling effect is discussed as an important mechanism to explain the low percolation threshold and nonlinear electric behavior of MSNC. A comparison between nanocomposites filled with CNTs and MSNC reinforced with CNTs and chopped carbon fibers demonstrates different percolation behaviors. Moreover, the influences of CNT position and orientation changes on the piezoresistivity of polymer nanocomposites are studied. Resistance change ratio as a function of applied strain demonstrates a non-linear behavior due to tunneling resistance change between CNTs. © 2019 Elsevier Ltd
Publication Date: 2021
Mechanics of Advanced Materials and Structures (15210596)28(4)pp. 331-342
A new mixed micromechanics method for a comprehensive analysis of the coefficient of thermal expansion (CTE) of carbon nanotube (CNT)/polymer nanocomposites with fully random microstructures is established. Comparisons between the model results and experiment clearly prove that for a more realistic prediction, considering random orientation and random distribution of CNTs, interphase region created due to the non-bonded van der Waals interactions between the CNT and polymer, non-straight shape and transversely isotropic behavior of CNT is essential in the modeling. The effects of interphase characteristics, geometrical properties and type of random distribution of CNTs on the nanocomposite CTEs are examined. © 2019 Taylor & Francis Group, LLC.
Publication Date: 2018
International Journal of Business Excellence (17560055)16(3)pp. 362-383
The purpose of this study is to create a model of succession management planning. The sample, consisting of 16 managers, was formed using snowball sampling. The data were analysed, using Strauss and Corbin’s (1998) three-stage coding process. Results indicate that the modern succession structure acts as a central theme in the design of the integrated model of succession planning. The causal conditions, at three levels of individual, organisational and managerial structures, mediated by the modern succession structure, have impact upon the succession management accomplishing strategies. These strategies are: policy making, candidate evaluation, candidate development, and the effectiveness assessment. Of course, confounding conditions at three micro, organisational and macro levels, as well as the contextual conditions in three areas of the organisational outlook, contexts realising organisational outlooks, and organisational policies, influence these strategies. The outcomes of these strategies and the influencing processes eventually find expressions at (individual), (unit) and (organisational) levels. Copyright © 2018 Inderscience Enterprises Ltd.
Hassanzadeh-aghdam, M.K.,
Mahmoodi m.j., M.J.,
Ansari, R. Publication Date: 2018
Journal of Alloys and Compounds (09258388)739pp. 164-177
A reliable and optimal design of metal matrix nanocomposites (MMNCs) reinforced by nanoscale particles critically requires establishing the accurate material-characterizing relations of such new systems. So, this paper presents an inclusive model to predict the elastic modulus, thermal expansion coefficient, yield strength and ultimate tensile strength of MMNCs containing nanoparticles. Size factor and the agglomerated state for the nanoparticles into the metal matrix, generation of dislocations by thermal mismatch and Orowan strengthening mechanism are considered in the analysis. The influence of volume fraction and diameter of nanoparticles, material properties of matrix and temperature difference on the MMNCs effective thermoelastic and strength properties are studied in detail. Generally, the predicted values match well with experimental data. The results prove that for accurate estimations of the elastic modulus and thermal expansion properties of the MMNCs reinforced with uniformly dispersed nanoparticles, the size factor must be considered. The more realistic characterizations of the yield strength and ultimate tensile strength of the MMNCs containing uniformly distributed nanoparticles could only be achieved with considering both thermal mismatch and Orowan strengthening mechanism. Additionally, when the nanoparticles are not well dispersed into the metal matrix, speculating the nanoparticles agglomerated state to acquire a more realistic prediction is critically essential. The MMNCs thermomechanical characteristics can be significantly improved by (i) increasing volume fraction, (iii) decreasing the nanoparticle diameter and (iii) uniform dispersion into the metal matrix. © 2017 Elsevier B.V.
Publication Date: 2024
Applied Physics A: Materials Science and Processing (14320630)130(4)
In this study, we investigate the mechanical properties of armchair phosphorene nanotubes using a combination of density functional theory (DFT) and the finite element method (FEM). Utilizing DFT, we determine the Young’s modulus, flexural rigidity, and Poisson's ratio of armchair phosphorene nanotubes. Subsequently, employing the finite element method based on the analogy of molecular mechanics and structural mechanics, we extract elemental properties for the finite element model. Our analysis reveals that the Young’s modulus of phosphorene nanotubes is intricately linked to the nanotube radius, demonstrating a dependency that converges as the radius increases. Furthermore, an increase in the aspect ratio of phosphorene nanotubes corresponds to an elevation in their Young’s modulus, with a notable exception for small aspect ratios where the impact on elastic properties is minimal. This research significantly advances our understanding of the mechanical behavior of armchair phosphorene nanotubes, offering insights crucial for unlocking their potential in diverse scientific and technological applications. The observed relationships between Young's modulus and nanotube parameters provide valuable considerations for the design and application of nanomaterials, making our findings relevant and influential in both scientific research and industrial endeavors. © The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature 2024.
Ansari, R.,
Mahmoudinezhad e., E.,
Alipour a., A.,
Hosseinzadeh m., Publication Date: 2013
Journal of Computational and Theoretical Nanoscience (15461955)10(9)pp. 2209-2215
This paper aims at exploring the characteristics of a single methane molecule encapsulated in semiinfinite single-walled carbon nanotubes. On the basis of Lennard-Jones potential function along with the continuum approximation and applied mathematics, single integrals are presented to formulate the van der Waals interaction energy and suction energy between a single methane molecule and a carbon nanotube. The preferred position and orientation of methane with regard to the nanotube axis has been fully investigated for different nanotube radii. To this end, it is assumed that the whole molecule rotates in all directions inside the nanotube. It is found that for certain radii of nanotubes in which the suction energy imparted to methane is negative, the whole methane molecule is symmetric with respect to the tube axis when it is inside the carbon nanotube. But, when the suction energy has positive values, as the tube radius increases the methane molecule gets closer to the wall of nanotube and finally locates near its wall in the form of a downward tripod. Furthermore, the optimum nanotube radius which gives rise to maximum suction energy has been calculated. The results obtained in this study can be conducted as means of further investigations for methane storage in carbon nanotubes. © 2013 American Scientific Publishers. All rights reserved.
Publication Date: 2019
Engineering Structures (18737323)181pp. 653-669
The main objective of this paper is to analyze the free vibration of arbitrary shaped thick functionally graded carbon nanotube-reinforced composite (FG-CNTRC) plates based on the higher-order shear deformation theory (HSDT) using a variational differential quadrature approach. By means of the generalized differential quadrature (GDQ) numerical operators and Hamilton's principle, the discretized equations of motion are obtained. In order to use the GDQ differential and integral operators appropriately, the coordinate transformation is considered through the conventional finite element approach for transforming the irregular domain of the plate into the regular computational one. Employing a unified numerical approach to analyze different shapes of thick FG-CNTRC plates based on HSDT is the main novel aspect of the present study. To imply the accuracy of the present model, a wide range of comparison studies are presented. The results indicate the efficiency of the developed numerical methodology to study the vibration of arbitrary shaped thick FG-CNTRC plates. Several results are also given to investigate the impacts of geometrical parameters and material properties on the vibrational behavior of FG-CNTRC plates. © 2018 Elsevier Ltd
