40,200 results match your criteria finite element


Nylon lattice design parameter effects on additively manufactured structural performance.

J Mech Behav Biomed Mater 2021 Oct 6;125:104869. Epub 2021 Oct 6.

Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, 20993, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA; Department of Mechanical Engineering, The University of Texas at Dallas, USA. Electronic address:

Lattice structures are used in a multitude of applications from medical to aerospace, and their adoption in these applications has been further enabled by additive manufacturing. Lattice performance is governed by a multitude of variables and estimating this performance may be needed during various phases of the design and validation process. Numerical modeling and constitutive relationships are common methodologies to assess performance, address risks, lower costs, and accelerate time to market for innovative and potentially life altering products. Read More

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October 2021

Efficient high-resolution TMS mapping of the human motor cortex by nonlinear regression.

Neuroimage 2021 Oct 12;245:118654. Epub 2021 Oct 12.

Methods and Development Group "Brain Networks", Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig, Germany; Technische Universität Ilmenau, Advanced Electromagnetics Group, Helmholtzplatz 2, 98693 Ilmenau, Germany.

Transcranial magnetic stimulation (TMS) is a powerful tool to investigate causal structure-function relationships in the human brain. However, a precise delineation of the effectively stimulated neuronal populations is notoriously impeded by the widespread and complex distribution of the induced electric field. Here, we propose a method that allows rapid and feasible cortical localization at the individual subject level. Read More

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October 2021

Multiscale modeling of cancellous bone considering full coupling of mechanical, electric and magnetic effects.

Biomech Model Mechanobiol 2021 Oct 15. Epub 2021 Oct 15.

Institute of Mechanics of Materials, Ruhr-Universität Bochum, 44801, Bochum, Germany.

Modeling of cancellous bone has important applications in the detection and treatment of fatigue fractures and diseases like osteoporosis. In this paper, we present a fully coupled multiscale approach considering mechanical, electric and magnetic effects by using the multiscale finite element method and a two-phase material model on the microscale. We show numerical results for both scales, including calculations for a femur bone, comparing a healthy bone to ones affected by different stages of osteoporosis. Read More

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October 2021

Translation of mechanical strain to a scalable biomanufacturing process for acellular matrix production from full thickness porcine bladders.

Biomed Mater 2021 Oct 15;16(6). Epub 2021 Oct 15.

Jack Birch Unit, Department of Biology, York Biomedical Research Institute, The University of York, York YO10 5DD, United Kingdom.

Bladder acellular matrix has promising applications in urological and other reconstructive surgery as it represents a naturally compliant, non-immunogenic and highly tissue-integrative material. As the bladder fills and distends, the loosely-coiled bundles of collagen fibres in the wall become extended and orientate parallel to the lumen, resulting in a physical thinning of the muscular wall. This accommodating property can be exploited to achieve complete decellularisation of the full-thickness bladder wall by immersing the distended bladder through a series of hypotonic buffers, detergents and nucleases, but the process is empirical, idiosyncratic and does not lend itself to manufacturing scale up. Read More

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October 2021

Characterization of a Novel Model of Lumbar Ligamentum Flavum Hypertrophy in Bipedal Standing Mice.

Orthop Surg 2021 Oct 15. Epub 2021 Oct 15.

Department of Orthopaedics, The Third Affiliated Hospital, Southern Medical University, Academy of Orthopaedics, Guangzhou, China.

Objective: To explore the main causes of hypertrophied ligamentum flavum (HLF) and the possibility of using bipedal standing mouse model to simulate the pathological changes in human HLF.

Methods: Thirty-two 8-week-old C57BL/6 male mice were randomly assigned to the experimental group (n = 16) and control group (n = 16). In the experimental group, mice were induced to adopt a bipedal standing posture by their hydrophobia. Read More

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October 2021

A numerical study of the distribution of chemotherapeutic drug carmustine in brain glioblastoma.

Drug Deliv Transl Res 2021 Oct 14. Epub 2021 Oct 14.

State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences (ICMS), University of Macau, Macau, China.

To cure the illness in the brain glioblastoma, the Gliadel wafer, as the first FDA-approved chemotherapy, was available on the market since 1997. Due to the complex studies in vivo, more and more researchers have paid their attention to investigate the dynamic process in the brain by numerical methods. This study aimed to simulate the drug concentration in the cavity after drug releases from Gliadel wafers into the brain tumor by a two-dimensional simulation. Read More

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October 2021

A modified source-detector configuration for the discrimination between normal and diseased human breast based on the continuous-wave diffuse optical imaging approach: a simulation study.

Lasers Med Sci 2021 Oct 14. Epub 2021 Oct 14.

Department of Biomedical Engineering, Faculty of Engineering, Helwan University, Cairo, Egypt.

Breast tumors are among the most common types of tumors that can affect both genders. It may spread to the whole breast without any symptoms. Therefore, the early detection and accurate diagnosis of breast tumors are significantly important. Read More

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October 2021

[Three-dimensional finite element analysis of traumatic mechanism of mandibular symphyseal fracture combined with bilateral intracapsular condylar fractures].

Beijing Da Xue Xue Bao Yi Xue Ban 2021 Oct;53(5):983-989

Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology & National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing 100081, China.

Objective: To analyze the biomechanical mechanism of mandibular symphyseal fracture combined with bilateral intracapsular condylar fractures using finite element analysis (FEA).

Methods: Maxillofacial CT scans and temporomandibular joint (TMJ) MRI were performed on a young male with normal mandible, no wisdom teeth and no history of TMJ diseases. The three-dimensional finite element model of mandible was established by Mimics and ANSYS based on the CT and MRI data. Read More

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October 2021

[Finite element analysis of the graft stresses after anterior cruciate ligament reconstruction].

Beijing Da Xue Xue Bao Yi Xue Ban 2021 Oct;53(5):865-870

Department of Sports Medicine, Peking University Third Hospital; Institute of Sports Medicine of Peking University; Beijing Key Laboratory of Sports Injuries, Beijing 100191, China.

Objective: To explore the stress distribution characteristics of the graft after anterior cruciate ligament (ACL) reconstruction, so as to provide theoretical reference for the surgical plan of ACL reconstruction.

Methods: Based on 3D MRI and CT images, finite element models of the uninjured knee joint and knee joint after ACL reconstruction were established in this study. The uninjured knee model included femur, tibia, fibula, medial collateral ligament, lateral collateral ligament, ACL and posterior cruciate ligament. Read More

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October 2021

The biomechanical effect of the relevant segments after facet-disectomy in different diameters under posterior lumbar percutaneous endoscopes: a three-dimensional finite element analysis.

J Orthop Surg Res 2021 Oct 14;16(1):593. Epub 2021 Oct 14.

Hospital of Chengdu University of Traditional Chinese Medicine, No. 39 Shi-er-qiao Road, Chengdu, 610072, Sichuan Province, People's Republic of China.

Objective: To evaluate the biomechanical influence after percutaneous endoscopic lumbar facetectomy in different diameters on segmental range of motion (ROM) and intradiscal pressure (IDP) of the relevant segments by establishing three dimensional finite element (FE) model.

Methods: An intact L3-5 model was successfully constructed from the CT of a healthy volunteer as Model A (MA). The Model B (MB), Model C (MC) and Model D (MD) were obtained through facetectomy on L4 inferior facet in diameters 7. Read More

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October 2021

Cutting mechanism of straight-tooth milling process of titanium alloy TC21 based on simulation and experiment.

Authors:
Zhang Lei Lei Pei

PLoS One 2021 14;16(10):e0258403. Epub 2021 Oct 14.

College of Mechanical and Energy Engineering, NingboTech University, Ningbo, China.

Due to the characteristics of high strength, high chemical activity and low heat conduction, titanium alloy materials are generally difficult to machine. As a typical titanium alloy with higher strength and lower heat conductivity, the machinability of titanium alloy TC21 is very poor and its cutting process is companied with larger cutting force and rapid tool wear. Straight-tooth milling tool is often used to cut the groove and side surface in the titanium alloy parts. Read More

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October 2021

Stress analysis in AAA does not predict rupture location correctly in patients with intraluminal thrombus.

Ann Vasc Surg 2021 Oct 11. Epub 2021 Oct 11.

Mines Saint-Etienne, Univ Lyon, INSERM, U 1059 Sainbiose, Centre CIS, F - 42023 Saint-Etienne France. Electronic address:

Objectives: A biomechanical approach to the rupture risk of an abdominal aortic aneurysm (AAA) could be a solution to ensure a personalized estimate of this risk. It is still difficult to know in what conditions, the assumptions made by biomechanics, are valid. The objective of this work was to determine the individual biomechanical rupture threshold and to assess the correlation between their rupture sites and the locations of their maximum stress comparing two computed tomography scan (CT) before and at time of rupture. Read More

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October 2021

A fast and automated FMT/XCT reconstruction strategy based on standardized imaging space.

IEEE Trans Med Imaging 2021 Oct 14;PP. Epub 2021 Oct 14.

The traditional finite element method-based fluorescence molecular tomography (FMT)/ X-ray computed tomography (XCT) imaging reconstruction suffers from complicated mesh generation and dual-modality image data fusion, which limits the application of in vivo imaging. To solve this problem, a novel standardized imaging space reconstruction (SISR) method for the quantitative determination of fluorescent probe distributions inside small animals was developed. In conjunction with a standardized dual-modality image data fusion technology, and novel reconstruction strategy based on Laplace regularization and L1-fused Lasso method, the in vivo distribution can be calculated rapidly and accurately, which enables standardized and algorithm-driven data process. Read More

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October 2021

Tissue engineering with mechanically induced solid-fluid transitions.

Adv Mater 2021 Oct 14:e2106149. Epub 2021 Oct 14.

Institute of Mechanical Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland.

Epithelia are contiguous sheets of cells that stabilize the shape of internal organs and support their structure by covering their surfaces. They acquire diverse morphological forms appropriate for their specific functions during embryonic development, such as the kidney tubules and the complex branching structures found in the lung. The maintenance of epithelial morphogenesis and homeostasis is controlled by their remarkable mechanics-epithelia can become elastic, plastic, and viscous by actively remodelling cell-cell junctions and modulating the distribution of local stresses. Read More

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October 2021

Oxygen Vacancy Injection as a Pathway to Enhancing Electromechanical Response in Ferroelectrics.

Adv Mater 2021 Oct 13:e2106426. Epub 2021 Oct 13.

Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.

Since their discovery in late 1940s, perovskite ferroelectric materials have become one of the central objects of condensed matter physics and materials science due to the broad spectrum of functional behaviors they exhibit, including electro-optical phenomena and strong electromechanical coupling. In such disordered materials, the static properties of defects such as oxygen vacancies is well explored, but the dynamic effects are less understood. In this work, we report the first observation of enhanced electromechanical response in BaTiO thin films driven via dynamic local oxygen vacancy control in piezoresponse force microscopy (PFM). Read More

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October 2021

Computational homogenisation based extraction of transverse tensile cohesive responses of cortical bone tissue.

Biomech Model Mechanobiol 2021 Oct 13. Epub 2021 Oct 13.

College of Science and Engineering, Flinders University, South Australia, 5042, Australia.

The numerical assessment of fracture properties of cortical bone is important in providing suggestions on patient-specific clinical treatments. We present a generic finite element modelling framework incorporating computational fracture approaches and computational homogenisation techniques. Finite element computations for statistical volume elements (SVEs) at the microscale are performed for different sizes with random osteon packing with a fixed volume fraction. Read More

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October 2021

Measurement bruise volume of olive during impact test using FEM and quality evaluation of extracted olive oil.

Food Sci Nutr 2021 Oct 3;9(10):5493-5508. Epub 2021 Aug 3.

Faculty of Agriculture Machinery, Agriculture and Natural Resources Department Tehran University Tehran Iran.

Mechanical damage is a phenomenon that always occurred in the postharvest process. Due to the inappropriate harvest and postharvest process of Olive that lead to the bruise phenomenon, the quality of the extracted olive oil reduces. In this study, the effect of olive damage on bruising volume and quality characteristics was investigated. Read More

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October 2021

Use of a Simulation Model to Investigate the Mechanisms of Sports-related Head Injuries.

Neurol Med Chir (Tokyo) 2021 Oct 14. Epub 2021 Oct 14.

Department of Neurosurgery, The Jikei University School of Medicine.

A simulation model was developed to better understand the mechanisms of brain injuries in sports. A three-dimensional model comprising approximately 1.22 million elements was constructed from cranial computed tomography images of adult male volunteers by the voxel method. Read More

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October 2021

Conservative Finite Element Modeling of EEG and MEG on Unstructured Grids.

IEEE Trans Med Imaging 2021 Oct 13;PP. Epub 2021 Oct 13.

For interpretation of electroencephalography (EEG) and magnetoencephalography (MEG) data, multiple solutions of the respective forward problems are needed. In this paper, we assess performance of the mixed-hybrid finite element method (MHFEM) applied to EEG and MEG modeling. The method provides an approximate potential and induced currents and results in a system with a positive semi-definite matrix. Read More

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October 2021

Statics performance of heavy-haul railway low-vibration track (LVT) under varying loading condition with the finite element method.

Sci Prog 2021 Oct;104(4):368504211036330

School of Civil Engineering, Central South University, Changsha, Hunan, China.

Low-Vibration Tracks (LVTs) are widely used in subway tunnels for their excellent performance, but the application in heavy-duty railways still requires a lot of feasibility studies. In this study, the statics performance of LVT under different axle loads, load direction, and load position is explored using the finite element software Abaqus. The Timoshenk beam element and nonlinear spring element 3D solid element are used to represent rails, fasteners, and the other track structure respectively. Read More

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October 2021

Fatigue behavior and stress distribution of molars restored with MOD inlays with and without deep margin elevation.

Clin Oral Investig 2021 Oct 13. Epub 2021 Oct 13.

Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), 777th Eng. Francisco José Longo Av., São José dos Campos, SP, 12245-000, Brazil.

Objectives: This study evaluated the effect of deep margin elevation (DME) and restorative materials (leucite-reinforced glass-ceramics [C] vs. indirect resin composite [R]) on the fatigue behavior and stress distribution of maxillary molars with 2-mm deep proximal margins restored with MOD inlay.

Methods: Fifty-two extracted human third molars were randomly assigned into four groups (n = 13): C; DME + C; R; and DME + R. Read More

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October 2021

Decreased cortical bone density and mechanical strength with associated elevated bone turnover markers at peri-pubertal peak height velocity: a cross-sectional and longitudinal cohort study of 396 girls with adolescent idiopathic scoliosis.

Osteoporos Int 2021 Oct 13. Epub 2021 Oct 13.

SH Ho Scoliosis Research Lab, Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR, China.

Decreased cortical bone density and bone strength at peak height velocity (PHV) were noted in girls with adolescent idiopathic scoliosis (AIS). These findings could provide the link to the previously reported observation that low bone mineral density (BMD) could contribute as one of the prognostic factors for curve progression that mostly occurs during PHV in AIS.

Introduction: As part of the studies related to aetiopathogenesis of AIS, we assessed bone qualities, bone mechanical strength and bone turnover markers (BTMs) focusing at the peri-pubertal period and PHV in AIS girls. Read More

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October 2021

Architecture of the cancellous bone in human proximal tibia based on P45 sectional plastinated specimens.

Surg Radiol Anat 2021 Oct 12. Epub 2021 Oct 12.

Department of Anatomy, College of Basic Medicine, Dalian Medical University, Dalian, 116044, Liaoning, China.

Purpose: To reveal differences in the pattern of trabecular architecture in the epiphysis and metaphysis of the proximal tibia.

Methods: The trabecular architecture of the proximal tibia was observed in 27 P45 plastinated knee specimens.

Results: In the medial and lateral condyles, under the articular cartilage surrounded by the medial or lateral meniscus, the cancellous bone is formed by thick and dense trabecular bands, which run longitudinally in the epiphysis and then pass through the epiphyseal line to terminate on the slanted cortex of the metaphysis. Read More

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October 2021

Realization of active metamaterials with odd micropolar elasticity.

Nat Commun 2021 Oct 12;12(1):5935. Epub 2021 Oct 12.

Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO, 65211, USA.

Materials made from active, living, or robotic components can display emergent properties arising from local sensing and computation. Here, we realize a freestanding active metabeam with piezoelectric elements and electronic feed-forward control that gives rise to an odd micropolar elasticity absent in energy-conserving media. The non-reciprocal odd modulus enables bending and shearing cycles that convert electrical energy into mechanical work, and vice versa. Read More

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October 2021

A comprehensive finite element model for studying Cochlear-Vestibular interaction.

Comput Methods Biomech Biomed Engin 2021 Oct 12:1-11. Epub 2021 Oct 12.

Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, USA.

We present a 3-D finite element (FE) model of the chinchilla's inner ear consisting of the entire cochlea structure and the vestibular system. The reaction of the basilar membrane to the head rotation and the reaction of ampulla to the stapes movement were investigated. These results demonstrate the existence of hearing-vestibular system interaction. Read More

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October 2021

Effect of Geometric Error on Friction Behavior of Cylinder Seals.

Polymers (Basel) 2021 Oct 7;13(19). Epub 2021 Oct 7.

Center for Rubber Composite Materials and Structures, Harbin Institute of Technology, Weihai 264209, China.

The tribological characteristics of the cylinder directly affect the operation accuracy of the pneumatic servo system. However, the geometric error has a significant effect on its tribological behavior and the related research is insufficient. Thus, the dynamic friction process of rubber seals has been investigated considering the influence of geometric errors. Read More

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October 2021

Material Modeling of PMMA Film for Hot Embossing Process.

Polymers (Basel) 2021 Oct 2;13(19). Epub 2021 Oct 2.

Department of Mechanical and Automotive Engineering, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-Gu, Seoul 01811, Korea.

This study provides an analysis of the hot embossing process with poly methyl methacrylate (PMMA) film. The hot embossing process engraves a fine pattern on a flexible film using a stamp, applied heat and pressure. As the quality of the embossing pattern varies according to various process variables, the mechanism of making the embossed shape is complicated and difficult to analyze. Read More

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October 2021

Modeling Brittle Fractures in Epoxy Nanocomposites Using Extended Finite Element and Cohesive Zone Surface Methods.

Polymers (Basel) 2021 Oct 1;13(19). Epub 2021 Oct 1.

Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA.

Linear elastic fracture modeling coupled with empirical material tensile data result in good quantitative agreement with the experimental determination of mode I fracture for both brittle and toughened epoxy nanocomposites. The nanocomposites are comprised of diglycidyl ether of bisphenol A cured with Jeffamine D-230 and some were filled with core-shell rubber nanoparticles of varying concentrations. The quasi-static single-edge notched bending (SENB) test is modeled using both the surface-based cohesive zone (CZS) and extended finite element methods (XFEM) implemented in the Abaqus software. Read More

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October 2021

Research on the Compound Optimization Method of the Electrical and Thermal Properties of SiC/EP Composite Insulating Material.

Polymers (Basel) 2021 Sep 30;13(19). Epub 2021 Sep 30.

State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China.

In this paper, in order to improve the electrical and thermal properties of SiC/EP composites, the methods of compounding different crystalline SiC and micro-nano SiC particles are used to optimize them. Under different compound ratios, the thermal conductivity and breakdown voltage parameters of the composite material were investigated. It was found that for the SiC/EP composite materials of different crystal types of SiC, when the ratio of α and β silicon carbide is 1:1, the electrical performance of the composite material is the best, and the breakdown strength can be increased by more than 10% compared with the composite material filled with single crystal particles. Read More

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September 2021

Crash Analysis of Aluminum/CFRP Hybrid Adhesive Joint Parts Using Adhesive Modeling Technique Based on the Fracture Mechanics.

Polymers (Basel) 2021 Sep 30;13(19). Epub 2021 Sep 30.

Department of Mechanical Engineering, Pusan National University, Pusan 46241, Korea.

This study describes the numerical simulation results of aluminum/carbon-fiber-reinforced plastic (CFRP) hybrid joint parts using the explicit finite-element solver LS-DYNA, with a focus on capturing the failure behavior of composite laminates as well as the adhesive capacity of the aluminum-composite interface. In this study, two types of adhesive modeling techniques were investigated: a tiebreak contact condition and a cohesive zone model. Adhesive modeling techniques have been adopted as a widely commercialized model of structural adhesives to simulate adhesive failure based on fracture mechanics. Read More

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September 2021