scholarly journals Computational optical palpation: a finite-element approach to micro-scale tactile imaging using a compliant sensor

2017 ◽  
Vol 14 (128) ◽  
pp. 20160878 ◽  
Author(s):  
Philip Wijesinghe ◽  
David D. Sampson ◽  
Brendan F. Kennedy
Keyword(s):  
Finite Element ◽  
Biomedical Applications ◽  
Imaging Method ◽  
Human Breast ◽  
Element Analysis ◽  
Element Approach ◽  
Breast Fibroadenoma ◽  
Compliant Layer ◽  
Sense Of Touch ◽  
Tactile Imaging

High-resolution tactile imaging, superior to the sense of touch, has potential for future biomedical applications such as robotic surgery. In this paper, we propose a tactile imaging method, termed computational optical palpation, based on measuring the change in thickness of a thin, compliant layer with optical coherence tomography and calculating tactile stress using finite-element analysis. We demonstrate our method on test targets and on freshly excised human breast fibroadenoma, demonstrating a resolution of up to 15–25 µm and a field of view of up to 7 mm. Our method is open source and readily adaptable to other imaging modalities, such as ultrasonography and confocal microscopy.

scholarly journals Are Suprapectineal Quadrilateral Surface Buttressing Plates Performances Superior to Traditional Fixation? A Finite Element Analysis

2021 ◽  
Vol 11 (2) ◽  
pp. 858
Author(s):  
Mara Terzini ◽  
Andrea Di Pietro ◽  
Alessandro Aprato ◽  
Stefano Artiaco ◽  
Alessandro Massè ◽  
...  
Keyword(s):  
Finite Element ◽  
Movement Analysis ◽  
High Energy ◽  
Clinical Analysis ◽  
Acetabular Fractures ◽  
Element Analysis ◽  
Bone Stress ◽  
Interfragmentary Movement ◽  
Element Approach ◽  
Transverse Fractures

Acetabular fractures have a high impact on patient’s quality of life, and because acetabular fractures are high energy injuries, they often co-occur with other pathologies such as damage to cartilage that could increase related morbidity; thus, it appears of primary importance developing reliable treatments for this disease. This work aims at the evaluation of the biomechanical performances of non-conservative treatments of acetabular fractures through a finite element approach. Two pelvic plates models (the standard suprapectineal plate—SPP, and a suprapectineal quadrilateral surface buttressing plate—SQBP) were analyzed when implanted on transverse or T-shaped fractures. The plates geometries were adapted to the specific hemipelvis, mimicking the bending action that the surgeon performs on the plate intraoperatively. Implemented models were tested in a single leg stance condition. The obtained results show that using the SQBP plate in transverse and T-shaped acetabular fractures generates lower bone stress if compared to the SPP plate. Interfragmentary movement analysis shows that the SQBP plate guarantees greater stability in transverse fractures. In conclusion, the SQBP plate seems worthy of further clinical analysis, having resulted as a promising option in the treatment of transverse and T-shaped acetabular fractures, able to reduce bone stress values and to get performances comparable, and in some cases superior, to traditional fixation.

Comparison of Buried Pipeline Crossing Assessments Using API RP 1102, Analytical Method and Finite Element Approach

2020 ◽  
Author(s):  
Nikhil Joshi ◽  
Pritha Ghosh ◽  
Jonathan Brewer ◽  
Lawrence Matta
Keyword(s):  
Finite Element ◽  
Analytical Method ◽  
Rapid Assessment ◽  
Buried Pipeline ◽  
The Finite Element Method ◽  
Buried Pipelines ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Element Approach ◽  
Multiple Loading

Abstract API RP 1102 provides a method to calculate stresses in buried pipelines due to surface loads resulting from the encroachment of roads and railroads. The API RP 1102 approach is commonly used in the industry, and widely available software allows for quick and easy implementation. However, the approach has several limitations on when it can be used, one of which is that it is limited to pipelines crossing as near to 90° (perpendicular crossing) as practicable. In no case can the crossing be less than 30° . In this paper, the stresses in the buried pipeline under standard highway vehicular loading calculated using the API RP 1102 method are compared with the results of two other methods; an analytical method that accounts for longitudinal and circumferential through wall bending effects, and the finite element method. The benefit of the alternate analytical method is that it is not subject to the limitations of API RP 1102 on crossing alignment or depth. However, this method is still subject to the limitation that the pipeline is straight and at a uniform depth. The fact that it is analytical in nature allows for rapid assessment of a number of pipes and load configurations. The finite element analysis using a 3D soil box approach offers the greatest flexibility in that pipes with bends or appurtenances can be assessed. However, this approach is time consuming and difficult to apply to multiple loading scenarios. Pipeline crossings between 0° (parallel) and 90° (perpendicular) are evaluated in the assessment reported here, even though these are beyond the scope of API RP 1102. A comparison across the three methods will provide a means to evaluate the level of conservatism, if any, in the API RP 1102 calculation for crossing between 30° and 90° . It also provides a rationale to evaluate whether the API RP 1102 calculation can potentially be extended for 0° (parallel) crossings.

Finite Element Analysis of Load Capacity on Coupling Clamps for Pipe

2012 ◽  
Vol 201-202 ◽  
pp. 741-744 ◽  
Author(s):  
Zhen Ning Hou ◽  
Jun Wu ◽  
Qing Wang ◽  
Hong Gen Tian ◽  
Nan Chao ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Optimization Design ◽  
Load Capacity ◽  
Three Dimensional ◽  
Process Conditions ◽  
Fe Model ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Element Approach

A finite element approach based on Ansys is developed to simulate stress intensity distribution in a three dimensional model of coupling clamp joint, which includes ferrules, pipe caps and bolts. The characteristics of stress intensity distributions of coupling clamp joint under strength pressure loading have been studied by means of the non-linear finite element method. The FE model can also predict the clamp quality and tolerances to be expected under different process conditions and define the most effective process parameters to influence the tolerances. The study could give us a better understanding on the mechanism and basis for optimization design of the coupling clamp joint.

Representative Volume Element for Mechanical Properties of Carbon Nanotube Nanocomposites Using Stochastic Finite Element Analysis

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Seyed Hamid Reza Sanei ◽  
Randall Doles
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Representative Volume Element ◽  
Volume Element ◽  
Length Scale ◽  
Stochastic Finite Element ◽  
Element Analysis ◽  
Representative Volume ◽  
Element Approach ◽  
Stochastic Finite Element Analysis

Abstract The aim of this study is to present a representative volume element (RVE) for nanocomposites with different microstructural features using a stochastic finite element approach. To that end, computer-simulated microstructures of nanocomposites were generated to include a variety of uncertainty present in geometry, orientation, and distribution of carbon nanotubes. Microstructures were converted into finite element models based on an image-based approach for the determination of elastic properties. For each microstructure type, 50 realizations of synthetic microstructures were generated to capture the variability as well as the average values. Computer-simulated microstructures were generated at different length scales to determine the change in mechanical properties as a function of length scale. A representative volume element is defined at a length scale beyond which no change in variability is observed. The results show that there is no universal RVE applicable to all properties and microstructures; however, the RVE size is highly dependent on microstructural features. Microstructures with agglomeration tend to require larger RVE. Similarly, random microstructures require larger RVE when compared with aligned microstructures.

Analysis of nonlinear electric field of hvdc wall bushing with a finite element approach

Open Physics ◽  
2005 ◽  
Vol 3 (4) ◽  
Author(s):  
Liming Dai ◽  
Longfu Luo
Keyword(s):  
Finite Element ◽  
Electric Field ◽  
High Voltage ◽  
Element Analysis ◽  
Nonlinear Characteristics ◽  
High Voltage Direct Current ◽  
Numerical Iteration ◽  
Numerical Assessment ◽  
Highly Nonlinear ◽  
Element Approach

AbstractThe present research intends to establish a numerical model, on the basis of a theoretical analysis, for describing and analyzing the electric field of High Voltage Direct Current (HVDC) wall bushing that demonstrates highly nonlinear characteristics. The wall bushing is subjected high voltage with nonlinear electric field and the relationship between the electric field intensity and the resistance of the insulators of the wall bushing is highly nonlinear. With a parameter design language of a Finite Element Analysis software package for carrying out the numerical calculations, the effects of the nonlinearity on the electric field can be well taken into consideration in performing the numerical assessment. A technique utilizing the numerical iteration is developed for quantifying the electric intensity of the electric field. With the model and the iteration technique established, the nonlinear characteristics of the HVDC wall bushing can be investigated with efficiency.

Stability of symmetric film-splitting between counter-rotating cylinders

1990 ◽  
Vol 216 ◽  
pp. 437-458 ◽  
Author(s):  
D. J. Coyle ◽  
C. W. Macosko ◽  
L. E. Scriven
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Liquid Films ◽  
Linear Stability Theory ◽  
Navier Stokes ◽  
End Effects ◽  
Element Analysis ◽  
Two Dimensional Flow ◽  
Element Approach ◽  
Film Splitting

The ribbing instability, an extremely common cause of non-uniform liquid films in coating operations, is investigated both theoretically and experimentally. The Navier–Stokes system for the two-dimensional flow in symmetric film-splitting in forward roll coating is solved by finite-element analysis. Stability of the flow with respect to three-dimensional disturbances is examined by applying linear stability theory in a consistent finite-element approach, taking Fourier components in the transverse direction. The resulting generalized asymmetric eigenproblem is solved for the growth rates of disturbances as functions of wavenumber. The theory accurately predicts the critical capillary number and wavenumber at the transition to large-amplitude ribs. A sensitive experimental technique for detecting the ribs was developed that relies on low-angle reflection of a focused strip of white light off the meniscus between the rolls. This allowed detection of much smaller amplitude ribs, and much smaller critical capillary numbers were measured. The results indicate that the transition to ribbing is an imperfect bifurcation due to end effects, and clarify earlier discordances in the literature.

scholarly journals Optimization of isolated and combined pad foundation using computer aided application of finite element approach

2021 ◽  
Vol 6 (3) ◽  
pp. 24-41
Author(s):  
Ubi Stanley E.
Keyword(s):  
Finite Element ◽  
Design Method ◽  
Bending Moment ◽  
Basic Structure ◽  
Ease Of Use ◽  
Foundation Design ◽  
Element Analysis ◽  
Mesh Selection ◽  
Element Approach ◽  
The Relationship

Most Finite Element packages provide means to generate meshes automatically. However, the user is usually confronted with the problem of not knowing whether the mesh generated is appropriate for the problem at hand. Since the accuracy of the Finite Element results is mesh dependent, mesh selection forms a very important step in the analysis of isolated and combined footing pad foundation. SAFE is an ultimate tools use in the design of concrete floors and foundation system, hence provide a suitable means for the user. From framing layout all the way through to detail drawing production, SAFE integrate every aspect of engineering design which are in one process easy and intuitive environment. SAFE provides unmatched benefits to the engineer with its truly unique combination of power, comprehensive capabilities, and ease-of-use. In the context of this research, we have plotted graphs showing the relationship between the nodes and displacement with the stress patterns as generated from the software. It is understood from the graph that multiple elements in the process of meshing will make the footing to be at equilibrium. The research also carry the shape deformed diagram which shows the deformation of the footing due to the impose load (stress) on the footing, it also give the bending moment diagram of the footings. The basic structure and analysis of the single and double pad footing foundations have been designed using Finite Element Analysis (FEA) with the failure planes being considered. The results obtained, it is assumed that FEA is an ideal design method that breaks foundation design into basic elements and nodes that shows the action of the loading on the footings.

Capability of SiC MOSFETs under Short-Circuit Tests and Development of a Thermal Model by Finite Element Analysis

2019 ◽  
Vol 963 ◽  
pp. 788-791 ◽  
Author(s):  
Daniela Cavallaro ◽  
Mario Pulvirenti ◽  
Edoardo Zanetti ◽  
Mario Giuseppe Saggio
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Physical Model ◽  
Thermal Model ◽  
Short Circuit ◽  
Laboratory Measurements ◽  
Element Analysis ◽  
Finite Element Approach ◽  
Element Approach

The aim of this paper is to analyze the SiC MOSFETs behavior under short circuit tests (SCT). In particular, the activity is focused on a deep evaluation of short circuit dynamic by dedicated laboratory measurements conducted at different conditions supported and compared by means of a robust physical model developed by Finite Element Approach.

Finite Element Analysis of Mechanical Characteristics on the Composite Rubber Suspension of Heavy Vehicle

2011 ◽  
Vol 121-126 ◽  
pp. 1702-1706
Author(s):  
Hui Pang ◽  
Hong Yan Li ◽  
Zong De Fang ◽  
Xiao Yuan Zhu
Keyword(s):  
Finite Element ◽  
Lightweight Design ◽  
Element Model ◽  
Heavy Vehicle ◽  
Virtual Design ◽  
Element Analysis ◽  
Static Mechanical ◽  
Element Approach ◽  
Suspension Stiffness ◽  
Static Mechanical Properties

Taking the composite rubber suspension of a 6×4 heavy vehicle as research object, an accurate finite element model for the composite suspension at loading states is firstly built with consideration of nonlinear contact between spring leaves, and then a new finite element approach for calculating and analyzing static mechanical properties of the composite rubber suspension. Finally, the stress distribution and deformation is analyzed under different loads by using Hypermesh software and the results can be applied to its strength design. And moreover, some primary principles of the composite rubber suspension stiffness and displacement changing with different loads are obtained, which provides reference basis for virtual design and lightweight design of the vehicle composite rubber suspension.

Design and Performance Analysis of Vehicle Tyre Pattern Material Using Finite Element Analysis and ANSYS R16.2

2018 ◽  
Vol 777 ◽  
pp. 426-431
Author(s):  
S. Nallusamy ◽  
M. Rajaram Narayanan ◽  
R. Suganthini Rekha
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Contact Pressure ◽  
Equivalent Stress ◽  
Frictional Stress ◽  
Inflation Pressure ◽  
Element Analysis ◽  
Modeling Software ◽  
Element Approach ◽  
And Performance

As it stands now, rubber has been the main material used in the making of pneumatic vehicle tyres. Speed of the vehicle depends on many factors like steering geometry, inflation pressure, vehicle load, road temperature and environmental conditions. The main aim of this research is to develop a finite element approach and computationally evaluate the performance of a steady-state rolling tyre by changing the tyre tread patterns. The tyre normally composed of rubber and body-ply was investigated with regards to the effect of the inflation pressure. Tyre modeling using six different types of patterns was completed by using Creo parametric 3D modeling software and then the tyre was discretized into small elements through ANSYS R16.2. The rim area of the tyre was fixed and pressure was applied to the inside surface of the rim. Finite element analysis was completed by using ANSYS R16.2 and equivalent stress, contact stress and contact pressure were found out to identify the best tyre pattern. From the final results it was observed that, Pattern-I had good agreement of results as compared to other type of patterns which showed medium frictional stress and contact pressure.

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