keyword
MENU ▼
Read by QxMD icon Read
search

Finite elements analysis

keyword
https://www.readbyqxmd.com/read/29791686/extruded-upper-first-molar-intrusion-comparison-between-unilateral-and-bilateral-miniscrew-anchorage
#1
Mari Miura Sugii, Bruno de Castro Ferreira Barreto, Waldemir Francisco Vieira-Júnior, Katia Regina Izola Simone, Ataís Bacchi, Ricardo Armini Caldas
OBJECTIVE: The aim of his study was to evaluate the stress on tooth and alveolar bone caused by orthodontic intrusion forces in a supraerupted upper molar, by using a three-dimensional Finite Element Method (FEM). METHODS: A superior maxillary segment was modeled in the software SolidWorks 2010 (SolidWorks Corporation, Waltham, MA, USA) containing: cortical and cancellous bone, supraerupted first molar, periodontal tissue and orthodontic components. A finite element model has simulated intrusion forces of 4N onto a tooth, directed to different mini-screw locations...
January 2018: Dental Press Journal of Orthodontics
https://www.readbyqxmd.com/read/29791378/design-of-an-adjustable-bipod-flexure-for-a-large-aperture-mirror-of-a-space-camera
#2
Bei Liu, Wei Wang, Yan-Jun Qu, Xu-Peng Li, Xiao Wang, Hui Zhao
An adjustable bipod flexure (ABF) technique for a large-aperture mirror of a space camera is presented. The proposed flexure mount can decrease the surface distortions caused by the machining error and the assembly error of the mirror assembly (MA) in a horizontal optical testing layout. Through the analysis of the compliance matrix of conventional bipod flexure, the positional relationship between the rotation center and the apex of the flexure is investigated. Then, the principle of the adjustable flexure, known as the trapezoidal switching principle, is proposed based on the analysis result...
May 20, 2018: Applied Optics
https://www.readbyqxmd.com/read/29791372/theoretical-compensation-of-static-deformations-of-freeform-multimirror-substrates
#3
Johannes Hartung, Henrik von Lukowicz, Jan Kinast
Varying temperatures influence the figure errors of freeform metal mirrors by thermal expansion. Furthermore, different materials lead to thermo-elastic bending effects. The paper presents a derivation of a compensation approach for general static loads. Utilizing perturbation theory, this approach works for shape compensation of substrates that operate in various temperature environments. Verification is made using a finite element analysis, which is further used to produce manufacturable CAD models. The remaining low spatial frequency errors are deterministically correctable using diamond turning or polishing techniques...
May 20, 2018: Applied Optics
https://www.readbyqxmd.com/read/29791368/design-and-analysis-for-a-bend-resistant-and-large-mode-area-photonic-crystal-fiber-with-hybrid-cladding
#4
Yan Qin, Huajun Yang, Ping Jiang, Fengji Gui, Weinan Caiyang, Biao Cao
In this paper, an asymmetric large-mode-area photonic crystal fiber (LMA-PCF) with low bending loss at a smaller bending radius is designed. The finite-element method with a perfectly matched layer boundary is used to analyze the performance of the PCF. To achieve LMA-PCF with low bending loss, the air holes with double lattice constants and different sizes at the core are designed. Numerical results show that this structure can achieve low bending loss and LMA with a smaller bending radius at the wavelength of 1...
May 10, 2018: Applied Optics
https://www.readbyqxmd.com/read/29789979/model-of-dissolution-in-the-framework-of-tissue-engineering-and-drug-delivery
#5
J A Sanz-Herrera, L Soria, E Reina-Romo, Y Torres, A R Boccaccini
Dissolution phenomena are ubiquitously present in biomaterials in many different fields. Despite the advantages of simulation-based design of biomaterials in medical applications, additional efforts are needed to derive reliable models which describe the process of dissolution. A phenomenologically based model, available for simulation of dissolution in biomaterials, is introduced in this paper. The model turns into a set of reaction-diffusion equations implemented in a finite element numerical framework. First, a parametric analysis is conducted in order to explore the role of model parameters on the overall dissolution process...
May 22, 2018: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/29789945/remote-monitoring-of-vibrational-information-in-spider-webs
#6
B Mortimer, A Soler, C R Siviour, F Vollrath
Spiders are fascinating model species to study information-acquisition strategies, with the web acting as an extension of the animal's body. Here, we compare the strategies of two orb-weaving spiders that acquire information through vibrations transmitted and filtered in the web. Whereas Araneus diadematus monitors web vibration directly on the web, Zygiella x-notata uses a signal thread to remotely monitor web vibration from a retreat, which gives added protection. We assess the implications of these two information-acquisition strategies on the quality of vibration information transfer, using laser Doppler vibrometry to measure vibrations of real webs and finite element analysis in computer models of webs...
May 22, 2018: Die Naturwissenschaften
https://www.readbyqxmd.com/read/29789777/a-normalized-shear-deformation-indicator-for-ultrasound-strain-elastography-in-breast-tissues-an-in-vivo-feasibility-study
#7
Jingfeng Jiang, Bo Peng
The shear deformation under loads contains useful information for distinguishing benign breast lesions from malignant ones. In this study, we proposed a normalized shear deformation indicator (NSDI) that was derived from the concept of principal strains. Since the NSDI requires both high-quality axial and lateral (parallel and perpendicular to the beam, resp.) displacement estimates, a strategy combining high-quality speckle tracking with signal "denoising" was employed. Both techniques were previously published by our group...
2018: BioMed Research International
https://www.readbyqxmd.com/read/29784052/the-effect-of-heart-failure-and-left-ventricular-assist-device-treatment-on-right-ventricular-mechanics-a-computational-study
#8
Jun I K Park, Aulia Khamas Heikhmakhtiar, Chang Hyun Kim, Yoo Seok Kim, Seong Wook Choi, Kwang Soup Song, Ki Moo Lim
BACKGROUND AND AIMS: Although it is important to analyze the hemodynamic factors related to the right ventricle (RV) after left ventricular assist device (LVAD) implantation, previous studies have focused only on the alteration of the ventricular shape and lack quantitative analysis of the various hemodynamic parameters. Therefore, we quantitatively analyzed various hemodynamic parameters related to the RV under normal, heart failure (HF), and HF incorporated with continuous flow LVAD therapy by using a computational model...
May 22, 2018: Biomedical Engineering Online
https://www.readbyqxmd.com/read/29783766/finite-element-analysis-of-electrospun-nanofibrous-mats-under-biaxial-tension
#9
Yunlei Yin, Jie Xiong
Due to the non-uniform material properties of electrospun nanofibrous mats and the non-linear characteristics of single fibers, establishing a numerical model that can fully explain these features and correctly describe their properties is difficult. Based on the microstructure of electrospun nanofibrous mats, two macroscopic continuum finite element (FE) models with a uniform or oriented nanofiber distribution were established to describe the mechanical behavior of nanofibrous mats under biaxial tension. The FE models were verified by biaxial tension experiments on silk fibroin/polycaprolactone nanofibrous mats...
May 19, 2018: Nanomaterials
https://www.readbyqxmd.com/read/29783121/the-influence-of-nail-blocking-conditions-in-cattle-femoral-fractures
#10
Leopoldo A Paolucci, Estevam B Las Casas, Rafael R Faleiros, Cahuê F R Paz, Sergio S Rocha Junior
BACKGROUND: To investigate the effect of different fixation strategies of the intramedullary interlocking nail (IIN) on the mechanical behavior of a polymeric implant applied for femoral fracture fixation in calves, and to evaluate the performance of a glass fiber-reinforced polymer applied in a bovine femoral fracture reduction system, five Holstein male animals with a mean weight (±SD) of 62.8 ± 20.4 kg and aged 74 ± 15 were used to generate biomechanical parameters for this study...
May 7, 2018: Research in Veterinary Science
https://www.readbyqxmd.com/read/29777960/utility-of-cement-injection-to-stabilize-split-depression-tibial-plateau-fracture-by-minimally-invasive-methods-a-finite-element-analysis
#11
D Belaid, T Vendeuvre, A Bouchoucha, F Brémand, C Brèque, P Rigoard, A Germaneau
BACKGROUND: Treatment for fractures of the tibial plateau is in most cases carried out by stable fixation in order to allow early mobilization. Minimally invasive technologies such as tibioplasty or stabilization by locking plate, bone augmentation and cement filling (CF) have recently been used to treat this type of fracture. The aim of this paper was to determine the mechanical behavior of the tibial plateau by numerically modeling and by quantifying the mechanical effects on the tibia mechanical properties from injury healing...
May 8, 2018: Clinical Biomechanics
https://www.readbyqxmd.com/read/29777322/sensitivity-analysis-of-ultrasonic-guided-waves-propagating-in-trilayered-bone-models-a-numerical-study
#12
Tho N H T Tran, Lawrence H Le, Mauricio D Sacchi, Vu-Hieu Nguyen
The fundamental ultrasonic guided modes are consistently observed in long bones ex vivo and in vivo. However, the responses of ultrasonic guided waves to the changes of cortical thickness, cortical elastic parameters, and thickness of the overlying soft tissues are not comprehensively understood. This paper systematically presents a sensitivity analysis of leaky Lamb modes to the geometry and material characteristics of layered bone model by means of semi-analytical finite element modeling. The stratified bone model is consisted of a transversely isotropic cortex with an overlying soft tissue and underlying marrow...
May 18, 2018: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/29777290/two-dimensional-grid-optimization-for-sedimentation-velocity-analysis-in-the-analytical-ultracentrifuge
#13
Haram Kim, Emre Brookes, Weiming Cao, Borries Demeler
Sedimentation velocity experiments performed in the analytical ultracentrifuge are modeled using finite-element solutions of the Lamm equation. During modeling, three fundamental parameters are optimized: the sedimentation coefficients, the diffusion coefficients, and the partial concentrations of all solutes present in a mixture. A general modeling approach consists of fitting the partial concentrations of solutes defined in a two-dimensional grid of sedimentation and diffusion coefficient combinations that cover the range of possible solutes for a given mixture...
May 17, 2018: European Biophysics Journal: EBJ
https://www.readbyqxmd.com/read/29773487/how-can-a-short-stem-hip-implant-preserve-the-natural-pre-surgery-force-flow-a-finite-element-analysis-on-a-collar-cortex-compression-concept-co-4
#14
B Eidel, A Gote, A Ohrndorf, H-J Christ
The present work proposes a simple, novel fixation concept for short stem hip endoprostheses, which preserves the pre-surgery force flow through femoral bone to an unprecedented extent. It is demonstrated by finite element analyses that a standard implant model endowed with minor geometrical changes can overcome bone loading reduction and can achieve almost physiological conditions. The numerical results underpin that the key aspect of the novel, so-called "collar cortex compression concept CO4 " is the direct, almost full load transmission from the implant collar to the resected femur cortex, which implies that the implant stem must be smooth and therefore interacts mainly by normal contact with the surrounding bone...
May 14, 2018: Medical Engineering & Physics
https://www.readbyqxmd.com/read/29772869/-progression-on-finite-element-modeling-method-in-scoliosis
#15
REVIEW
Ning Fan, Lei Zang, Yong Hai, Peng Du, Shuo Yuan
Scoliosis is a complex spinal three-dimensional malformation with complicated pathogenesis, often associated with complications as thoracic deformity and shoulder imbalance. Because the acquisition of specimen or animal models are difficult, the biomechanical study of scoliosis is limited. In recent years, along with the development of the computer technology, software and image, the technology of establishing a finite element model of human spine is maturing and it has been providing strong support for the research of pathogenesis of scoliosis, the design and application of brace, and the selection of surgical methods...
April 25, 2018: Zhongguo Gu Shang, China Journal of Orthopaedics and Traumatology
https://www.readbyqxmd.com/read/29772826/sensitivity-enhancement-of-fbg-based-strain-sensor
#16
Ruiya Li, Yiyang Chen, Yuegang Tan, Zude Zhou, Tianliang Li, Jian Mao
A novel fiber Bragg grating (FBG)-based strain sensor with a high-sensitivity is presented in this paper. The proposed FBG-based strain sensor enhances sensitivity by pasting the FBG on a substrate with a lever structure. This typical mechanical configuration mechanically amplifies the strain of the FBG to enhance overall sensitivity. As this mechanical configuration has a high stiffness, the proposed sensor can achieve a high resonant frequency and a wide dynamic working range. The sensing principle is presented, and the corresponding theoretical model is derived and validated...
May 17, 2018: Sensors
https://www.readbyqxmd.com/read/29770490/functional-magnetic-resonance-electrical-impedance-tomography-fmreit-sensitivity-analysis-using-an-active-bidomain-finite-element-model-of-neural-tissue
#17
Rosalind J Sadleir, Fanrui Fu, Munish Chauhan
PURPOSE: A direct method of imaging neural activity was simulated to determine typical signal sizes. METHODS: An active bidomain finite-element model was used to estimate approximate perturbations in MR phase data as a result of neural tissue activity, and when an external MR electrical impedance tomography imaging current was added to the region containing neural current sources. RESULTS: Modeling-predicted, activity-related conductivity changes should produce measurable differential phase signals in practical MR electrical impedance tomography experiments conducted at moderate resolution at noise levels typical of high field systems...
May 16, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29769767/a-comparative-study-on-the-stress-distribution-around-dental-implants-in-three-arch-form-models-for-replacing-six-implants-using-finite-element-analysis
#18
Maryam Zarei, Mahmoud Jahangirnezhad, Hojatollah Yousefimanesh, Maryam Robati, Hossein Robati
Background: Dental implant is a method to replacement of missing teeth. It is important for replacing the missed anterior teeth. In vitro method is a safe method for evaluation of stress distribution. Finite element analysis as an in vitro method evaluated stress distribution around replacement of six maxillary anterior teeth implants in three models of maxillary arch. Materials and Methods: In this in vitro study, using ABAQUS software (Simulia Corporation, Vélizy-Villacoublay, France), implant simulation was performed for reconstruction of six maxillary anterior teeth in three models...
March 2018: Journal of Indian Society of Periodontology
https://www.readbyqxmd.com/read/29769146/finite-element-analysis-of-the-tibial-bone-graft-in-cementless-total-knee-arthroplasty
#19
Koji Totoribe, Etsuo Chosa, Go Yamako, Hiroaki Hamada, Koki Ouchi, Shutaro Yamashita, Gang Deng
BACKGROUND: Achieving stability of the tibial implant is essential following cementless total knee arthroplasty with bone grafting. We investigated the effects of bone grafting on the relative micromotion of the tibial implant and stress between the tibial implant and adjacent bone in the immediate postoperative period. METHODS: Tibial implant models were developed using a nonlinear, three-dimensional, finite element method. On the basis of a preprepared template, several bone graft models of varying sizes and material properties were prepared...
May 16, 2018: Journal of Orthopaedic Surgery and Research
https://www.readbyqxmd.com/read/29763505/influence-of-alveolar-bone-defects-on-the-stress-distribution-in-quad-zygomatic-implant-supported-maxillary-prosthesis
#20
Yuanyuan Duan, Ravi Chandran, Denise Cherry
PURPOSE: The purpose of this study was to create three-dimensional composite models of quad zygomatic implant-supported maxillary prostheses with a variety of alveolar bone defects around implant sites, and to investigate the stress distribution in the surrounding bone using the finite element analysis (FEA) method. MATERIALS AND METHODS: Three-dimensional models of titanium zygomatic implants, maxillary prostheses, and human skulls were created and assembled using Mimics based on microcomputed tomography and cone beam computed tomography images...
May 2018: International Journal of Oral & Maxillofacial Implants
keyword
keyword
68081
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"