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finite-element-analysis
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Performance analysis of an outer rotor variable reluctance resolver
, Article IEEE Sensors Journal ; Volume 22, Issue 18 , 2022 , Pages 17761-17768 ; 1530437X (ISSN) ; Tootoonchian, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Variable reluctance resolver (VR-Resolver) is a robust electromagnetic sensor that provides position information for closed-loop control systems of permanent magnet synchronous motors (PMSMs). For specific motion control applications, an outer rotor structure is presented for the VR-Resolver in this article with a nonoverlapping tooth-coil windings configuration to simplify the manufacturing process. The study on the structure of the proposed position sensor is carried out, followed by the description of the working principle. The presented outer rotor VR-Resolver is simulated and its performance is investigated in detail with the aid of transient finite-element analysis (TFEA). Sensitivity...
Large deformation of shape-memory polymer-based lattice metamaterials
, Article International Journal of Mechanical Sciences ; Volume 232 , 2022 ; 00207403 (ISSN) ; Jebellat, E ; Roudbarian, N ; Mohammadi, K ; Movahhedy, M. R ; Asle Zaeem, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Through advanced computational analysis, this work demonstrates that metamaterial structures when made by shape-memory polymers (SMPs) can provide unique intelligent mechanical behavior. For the first time, geometrical effects, pertaining to low and ultra-low densities, on the thermomechanical behavior of SMP-based octet-truss lattice meta-structures are studied in this work. A reliable constitutive thermo-visco-hyperelastic model is applied to analyze the shape-memory behavior of several designed octet-truss lattices with ultra-low and low relative densities, ranging from 0.04 to 0.23. Different compressive strain values are tested to determine the effect of pre-straining. It is concluded...
An investigation of shear failure in welded channel and angle brace members
, Article Structures ; Volume 45 , 2022 , Pages 1287-1306 ; 23520124 (ISSN) ; Maleki, S ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Shear yielding (SY) and shear rupture (SR) are base metal failure modes in welded connections of brace members to gusset plates. Although gusset plated connections have been extensively investigated in the past nonetheless, the shear failure limit states of welded brace members have not received significant attention. This paper aims to shed some light on the shear failure mechanism and strength of welded brace members consisting of single and double channels and angles. For this purpose, a nonlinear finite element (FE) model with ductile damage simulation is developed and validated against the authors’ experiments and other available test results. Then an extensive parametric study using...
Optimization of cervical cage and analysis of its base material: A finite element study
, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 236, Issue 11 , 2022 , Pages 1613-1625 ; 09544119 (ISSN) ; Abollfathi, N ; Khajehzhadeh, M ; Hassani Gangaraj, M ; Sharif University of Technology
SAGE Publications Ltd
2022
Abstract
Nowadays, cervical disorders are common due to human lifestyles. Accordingly, the cage design should be optimized as an essential issue. For an optimal design, an objective function is utilized to calculate the proper geometrical parameters. Additionally, the base material of the cage plays a key role in its functionality and final cost. Novel materials are currently introduced with more compatibility with the bone in terms of mechanical and chemical properties. In this study, a cervical cage was modeled based on PEEK material with three types of tooth designs on its surface. The cervical cage is assumed to be implanted between C6 and C7 vertebrae. The geometric parameters of the cage were...
Adjacent segments biomechanics following lumbar fusion surgery: a musculoskeletal finite element model study
, Article European Spine Journal ; Volume 31, Issue 7 , 2022 , Pages 1630-1639 ; 09406719 (ISSN) ; Arjmand, N ; Shirazi-Adl, A ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
Purpose: This study exploits a novel musculoskeletal finite element (MS-FE) spine model to evaluate the post-fusion (L4–L5) alterations in adjacent segment kinetics. Methods: Unlike the existing MS models with idealized representation of spinal joints, this model predicts stress/strain distributions in all passive tissues while organically coupled to a MS model. This generic (in terms of musculature and material properties) model uses population-based in vivo vertebral sagittal rotations, gravity loads, and an optimization algorithm to calculate muscle forces. Simulations represent individuals with an intact L4–L5, a preoperative severely degenerated L4–L5 (by reducing the disc height by ~...
Shaking table test for assessing the seismic performance of semi-anchored steel water tanks
, Article Thin-Walled Structures ; Volume 176 , 2022 ; 02638231 (ISSN) ; Shahrouz Sotudeh, A ; Bakhshi, A ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
The seismic responses of steel water tanks are unconventional given their complex dynamic behavior and the sources of nonlinearity. Therefore, providing a reliable, finite-element model is instrumental in better understanding their dynamic behavior and improving the design conditions. This paper aims to evaluate the seismic performance of steel water tanks using shaking table tests and provide a finite-element reference model for simulating real-size, semi-anchored water tanks by conducting a series of large-scale tests in the Shaking Table Lab of the Sharif University of Technology (SUT). Since scaling the tank requires a difficult process involving changing the liquid density, this paper...
Novel force–displacement control passive finite element models of the spine to simulate intact and pathological conditions; comparisons with traditional passive and detailed musculoskeletal models
, Article Journal of Biomechanics ; Volume 141 , 2022 ; 00219290 (ISSN) ; Ebrahimkhani, M ; Arjmand, N ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Passive finite element (FE) models of the spine are commonly used to simulate intact and various pre- and postoperative pathological conditions. Being devoid of muscles, these traditional models are driven by simplistic loading scenarios, e.g., a constant moment and compressive follower load (FL) that do not properly mimic the complex in vivo loading condition under muscle exertions. We aim to develop novel passive FE models that are driven by more realistic yet simple loading scenarios, i.e., in vivo vertebral rotations and pathological-condition dependent FLs (estimated based on detailed musculoskeletal finite element (MS-FE) models). In these novel force–displacement control FE models,...
Experimental investigation and finite element modelling of PMMA/carbon nanotube nanobiocomposites for bone cement applications
, Article Soft Matter ; Volume 18, Issue 36 , 2022 , Pages 6800-6811 ; 1744683X (ISSN) ; Khakbiz, M ; Chagami, M ; Bagheri, R ; Chashmi, F. S ; Akbari, B ; Shakibania, S ; Lee, K. B ; Sharif University of Technology
Royal Society of Chemistry
2022
Abstract
Multi-walled carbon nanotubes (MWCNTs) are one of the preferred candidates for reinforcing polymeric nanobiocomposites, such as acrylic bone type of cement. In this study, at first, bulk samples of the reinforced polymethylmethacrylate (PMMA) matrix were prepared with 0.1, 0.25, and 0.5 wt per wt% of MWCNTs by the casting method. Tensile and three-point bending tests were performed to determine the essential mechanical properties of bone cement, such as tensile and bending strengths. The tensile fracture surfaces were investigated by scanning electron microscopy (SEM). The commercial software (Abaqus) was used to conduct finite element analysis (FEA) by constructing a representative volume...
Enhanced singlet oxygen production under nanoconfinement using silica nanocomposites towards improving the photooxygenation’s conversion
, Article Journal of Nanoparticle Research ; Volume 24, Issue 9 , 2022 ; 13880764 (ISSN) ; Kazemeini, M ; Sharif University of Technology
Springer Science and Business Media B.V
2022
Abstract
In this contribution, the effect of physical immobilization of methylene blue (MB) into silica nanocomposites was investigated on the conversion and selectivity of the photooxygenation of anthracene and dihydroartemisinic acid (DHAA). Physically immobilized photocatalysts were synthesized through a developed Stöber method and were thoroughly characterized by UV–Vis, FTIR, XRD, XPS, SEM, TEM, HR-TEM, BET-BJH, and EDX analyses. Based on the TEM and UV–Vis results, it was determined that enhancement of the MB concentration as an organocatalyst for the Stöber reaction led to an increase in the size of the nanoparticles from 54 to 183 nm and a 21 nm blue shift in their UV–Vis spectra. Moreover,...
Effects of plate contouring quality on the biomechanical performance of high tibial osteotomy fixation: A parametric finite element study
, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 236, Issue 3 , 2022 , Pages 356-366 ; 09544119 (ISSN) ; Farahmand, F ; Sharif University of Technology
SAGE Publications Ltd
2022
Abstract
Locking plates have threaded holes, in which threaded-head screws are affixed. Hence, they do not need to be in intimate contact with underlying bone to provide fixation. There are, however, reports that a large distance between the plate and the bone might cause clinical complications such as delayed union or nonunion, screw pull out, and screw and plate breakage. Considering the diversity in the capabilities and costs of different plate customization techniques, the purpose of this study was to investigate the effect of the plate contouring quality on the biomechanical performance of high tibial osteotomy (HTO) fixation. A finite element model of proximal tibia was developed in Abaqus,...
Experimental investigation of double corrugated steel plate shear walls
, Article Journal of Constructional Steel Research ; Volume 190 , 2022 ; 0143974X (ISSN) ; Maleki, S ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
In this research, the cyclic performance of double corrugated steel plate shear walls (DCSPSWs) is investigated experimentally and confirmed numerically. Three half-scale one-story single-bay specimens with different infill plate designs were constructed and tested under lateral cyclic loads. The design parameters examined were the connection between the corrugated plates and the connection between the infill plate and the columns. The results showed that regardless of the infill plate design, the DCSPSWs had a spindle-shaped hysteresis curve with good cyclic performance. However, the beam-only-connected DCSPSW exhibited slightly lower lateral load resistance. Finite element (FE) models of...
A state-of-the-art review of the fabrication and characteristics of titanium and its alloys for biomedical applications
, Article Bio-Design and Manufacturing ; Volume 5, Issue 2 , 2022 , Pages 371-395 ; 20965524 (ISSN) ; Rezvani Ghomi, E ; Alipour, S ; Ramakrishna, S ; Liana Sukiman, N ; Sharif University of Technology
Springer
2022
Abstract
Abstract: Commercially pure titanium and titanium alloys have been among the most commonly used materials for biomedical applications since the 1950s. Due to the excellent mechanical tribological properties, corrosion resistance, biocompatibility, and antibacterial properties of titanium, it is getting much attention as a biomaterial for implants. Furthermore, titanium promotes osseointegration without any additional adhesives by physically bonding with the living bone at the implant site. These properties are crucial for producing high-strength metallic alloys for biomedical applications. Titanium alloys are manufactured into the three types of α, β, and α + β. The scientific and clinical...
Evaluation of plasticity-based concrete constitutive models under monotonic and cyclic loadings
, Article Structural Design of Tall and Special Buildings ; Volume 31, Issue 6 , 2022 ; 15417794 (ISSN) ; Asgarpoor, M ; Epackachi, S ; Sharif University of Technology
John Wiley and Sons Ltd
2022
Abstract
This paper evaluates the applicability of several concrete models to simulate the behavior of concrete elements under monotonic and cyclic loadings. Several robust constitutive models based on the combination of plasticity and continuum damage or plasticity and smeared crack approach are selected. The behavior of one concrete element is evaluated under different uniaxial compression, uniaxial tension, biaxial compression, biaxial tension, biaxial compression–tension, and triaxial compression loads. Then, the applicability of the concrete models is investigated for two flexural beams under cyclic loading. Five concrete models available in the versatile finite element-based software LS-DYNA...
Improved design of an outer rotor six-phase induction motor with variable turn pseudo-concentrated windings
, Article IEEE Transactions on Energy Conversion ; Volume 37, Issue 2 , 2022 , Pages 1020-1029 ; 08858969 (ISSN) ; Tahami, F ; Capolino, G. A ; Nasiri Gheidari, Z ; Henao, H ; Sahebazamani, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
In this paper, a novel six-phase outer rotor induction motor equipped with pseudo-concentrated windings is introduced as a robust, reliable, and low-cost solution. Multiple aspects of the proposed motor structure have been investigated such as a design algorithm and an analytical modeling based on the modified winding function considering the skew effect. The effect of using variable number of turns for the coils has been examined on the pseudo-concentrated windings. An appropriate optimization problem has been also defined to maximize the power factor and efficiency and to minimize the output torque ripple. The designed motor has been fabricated to verify the accuracy of the design...
Experimental and numerical investigation of minimum required fiber content in bending characteristics of 100 MPa UHPC-formulated concrete
, Article Case Studies in Construction Materials ; Volume 16 , 2022 ; 22145095 (ISSN) ; Khaloo, A ; Hassanpour, S ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
The present study investigates the lowest possible amount of steel and polypropylene fibers in improving the compressive and flexural strength, stiffness, and energy capacity of high strength 100 MPa concrete with a mix design similar to that of Ultra-High Performance Concrete (UHPC). Twenty-eight 100 × 200 mm cylindrical specimens with 0%, 0.2%, 0.4%, and 0.6% volumetric percentage of short steel fibers and polypropylene fibers were fabricated, which were at the lowest predicted percentages with respect to fiber content recommended in the literature. To assess the flexural performance of fiber-reinforced concrete panels, specimens with dimensions of 200 × 600 × 20 mm were made with the same...
Design of the micropump and mass-transfer compartment of a microfluidic system for regular nonenzymatic glucose measurement
, Article Biotechnology Reports ; Volume 34 , 2022 ; 2215017X (ISSN) ; Saidi, M. S ; Kazemzadeh Hannani, S ; Sharif University of Technology
Elsevier B.V
2022
Abstract
The aim of this paper is to design and numerically simulate the mass-transfer compartment and piezoelectric micropump of an implantable integrated microfluidic device for regular microdialysis-based nonenzymatic measurement of glucose level in diabetic patients. The device function is based on the process that the piezoelectric micropump pumps the dialysis fluid into the mass-transfer compartment microchannels, where the interstitial fluid (ISF) glucose diffusion into this dialysis fluid gives it a glucose content, then detected and measured in the sensor section. This diffusion takes place through the semipermeable membranes located in the microchannels at the base of the hollow...
Effects of support conditions and arrangement of prestressed rocking columns on the displacement of concrete frames under dynamic loads
, Article Bulletin of Earthquake Engineering ; Volume 20, Issue 8 , 2022 , Pages 4175-4212 ; 1570761X (ISSN) ; Khaloo, A ; Sharif University of Technology
Springer Science and Business Media B.V
2022
Abstract
In this paper, the effects of rocking and fixed base prestressed columns and conventional reinforced concrete columns on the response of frames are investigated. Also, the influence of some selected rocking base prestressed columns on the response of the concrete frame was studied. Three types of a concrete frame with conventional Reinforced Concrete columns, rocking, and fixed base prestressed columns were modeled using the finite element method in Opensees software. The details of the simulation of the rocking and fixed base columns in Opensees are described precisely. The results obtained from the models were compared with those of the literature to evaluate the validity of the results....
Patient-specific fluid–structure interaction simulation of the LAD-ITA bypass graft for moderate and severe stenosis: A doubt on the fractional flow reserve-based decision
, Article Biocybernetics and Biomedical Engineering ; Volume 42, Issue 1 , 2022 , Pages 143-157 ; 02085216 (ISSN) ; Firoozabadi, B ; Pakravan, H. A ; Ahmadi Tafti, S. H ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Fractional flow reserve (FFR)-based decision improves the outcomes of percutaneous coronary intervention (PCI) for some patients, while its effectiveness in improving the results of coronary artery bypass graft (CABG) is unclear, in particular for moderate stenosis. It may be due to the fact that FFR cannot take into account the impacts of competitive flow (CF), intimal hyperplasia (IH), as well as compliance mismatch (CMM). As a result, two questions arise 1) whether FFR is a sufficient factor to decide to perform the CABG for patients with moderate to severe stenosis or not and 2) whether post-operative FFR shows the effectiveness of a graft. To shed light on this matter, two...
A multi-objective approach to optimize the weight and stress of the locking plates using finite element modeling
, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 236, Issue 2 , 2022 , Pages 188-198 ; 09544119 (ISSN) ; Nourani, A ; Chizari, M ; Sharif University of Technology
SAGE Publications Ltd
2022
Abstract
This paper aims to identify an optimum bone fracture stabilizer. For this purpose, three design variables including the ratio of the screw diameter to the plate width at three levels, the ratio of the plate thickness to the plate width at three levels, and the diameter of the bone at two levels were selected for analysis. Eighteen 3D verified finite element models were developed to examine the effects of these parameters on the weight, maximum displacement and maximum von Mises stress of the fixation structure. Considering the relations between the inputs and outputs using multivariate regression, a genetic algorithm was used to find the optimal choices. Results showed that the diameter of...
Optimal design and performance analysis of a double-sided multiturn wound-rotor resolver
, Article IEEE/ASME Transactions on Mechatronics ; Volume 27, Issue 1 , 2022 , Pages 493-500 ; 10834435 (ISSN) ; Saneie, H ; Nasiri Gheidari, Z ; Tootoonchian, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Multispeed resolvers are used in the applications that need higher accuracy. However, they suffer from losing absolute position information. To overcome this challenge and improve the reliability of detecting position, the use of multiturn resolvers is recommended. The conventional configuration of multiturn resolver is using two individual resolvers on one shaft and into a common frame. Using such configuration needs special care on setting the distance between two resolvers. In this article, a new structure based on a dual side configuration is proposed. The performance of the double-sided resolver is analyzed and optimized using an analytical model based on a magnetic equivalent circuit....