Vessel Sealing Using the Bipolar Electrosurgical Method

2007 ◽  
Author(s):  
Matthew W. Chastagner ◽  
Scott F. Miller ◽  
Albert J. Shih ◽  
James D. Geiger
Keyword(s):  
Experimental Data ◽  
Porcine Model ◽  
Electrical Current ◽  
Experimental Results ◽  
Element Analysis ◽  
Fea Model ◽  
Vessel Sealing ◽  
Maximum Temperatures ◽  
Insight Into

The electrosurgical sealing method has risen to prominence in recent years as more vessel sealing procedures are being conducted in minimally invasive surgery. Electrosurgical sealing works by applying electrical current to coagulate and denature proteins in the vessel, thereby creating a bond. In this study, experiments were conducted to seal 3 and 8 mm diameter vessels in a porcine model with a bipolar electrosurgical device and measure the electrical voltage and current, and temperature distribution in the vessel near the area of the seal. The vessel seal was modeled with finite element analysis (FEA) and compared to the experimental data. FEA allow for insight into the correlation of temperature to quality of the seal in the vessel. The maximum temperatures were 83°C and 63°C in the 3 and 8 mm vessels, respectively. Validation of the experimental results was attempted through the use of a simplified FEA model. The model showed similar thermal profiles near the electrode, but further downstream temperatures did not rise as fast as the experimental results. Further refinement to overcome limitations in the model is identified.

Ontology Cohesion and Coupling Metrics

2017 ◽  
Vol 13 (4) ◽  
pp. 1-26 ◽  
Author(s):  
Sandeep Kumar ◽  
Niyati Baliyan ◽  
Shriya Sukalikar
Keyword(s):  
Experimental Results ◽  
Continuous Scale ◽  
Modular Ontology ◽  
Insight Into ◽  
Structural Aspects

Cohesion and coupling metrics for a modular ontology provide an insight into the efficiency of the modularization technique employed. Most of such metrics are either syntax based or do not account for ontology hierarchy. The authors propose cohesion and coupling metrics with continuous scale of measurement for modular ontology via deducing the degree of dependence among ontology components, thereby, handling structural aspects of ontology. The proposed metrics further handle the subtle differences between the type of links. The metrics have been analytically validated using well-established frameworks and the experimental results compared with the existing works, in terms of their cohesion and coupling values as well as the features of ontologies that they can measure. The proposed metrics are unambiguous and can be applied to any type of ontology in order to facilitate the assessment of the quality of an ontology or a partition thereof.

The Optimization Design of Dental Implant after the Mandible Tumor Resection and Reconstruction

2013 ◽  
Vol 702 ◽  
pp. 318-322
Author(s):  
Wen Zheng Wu ◽  
Ji Zhao ◽  
Lei Zhang ◽  
Xing Tian Qu ◽  
Di Zhao ◽  
...  
Keyword(s):  
Optimization Design ◽  
Tumor Resection ◽  
Biomechanical Analysis ◽  
Secondary Surgery ◽  
Element Analysis ◽  
Fea Model ◽  
3D Fea ◽  
Mandible Defect ◽  
Operation Cost

Mandible defect and the lack of dentition may result in facial deformity and chewing organ defects. It happens after the surgery of oral and maxillofacial tumors. This study aims at this problem. In this study, Finite Element Analysis (FEA) was employed to reconstruct the implanted mandible for customized patient. The 3D FEA model has great importance for biomechanical analysis. Though the analysis of the biomechanical situation with different numbers of dental implants, we can optimize the location and quantity of the implants. In this way, we can improve the quality of the implants, reduce the pain of patients, reduce the operation cost and avoid secondary surgery.

A Study on Bursting Pressure of Thin-Walled Cylinders

2008 ◽  
Author(s):  
Yang-Chun Deng ◽  
Gang Chen ◽  
Liang Sun ◽  
Tong Xu
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Failure Criterion ◽  
Pressure Vessels ◽  
Experimental Results ◽  
Bursting Pressure ◽  
Element Analysis ◽  
Instability Strain ◽  
Thin Walled

In this paper, we investigated the bursting pressure of thin-walled cylinders. Considering the strain hardening behavior of materials and the geometry deformation of pressure vessels, we derived the instability strain of thin-walled cylinders with a Swift-type stress-strain relationship, and used it as a failure criterion. Consequently, the instability stress was obtained and used to determine the maximum load-bearing capacity of thin-walled cylinders, that is, bursting pressure. The analytical solutions were compared with finite element analysis and bursting experimental results on different size thin-walled cylindrical pressure vessels manufactured from three different materials. It was turned out that it is reasonable to adopt instability strain as a failure criterion and use instability pressure as burst pressure. In the finite element analysis, the material parameters used were from raw experimental data or fitted values of experimental data. For both cases, finite element predications on instability strain and bursting pressure gave around the same values, close to experimental results. Therefore, based on finite element analyses, the instability strain and bursting pressure can be calculated by using true stress-strain curves directly measured from experiments, without the need to assume any specific material type.

Quality of Refractory Materials in the Technological Process

2012 ◽  
Vol 524-527 ◽  
pp. 2026-2030
Author(s):  
Marek Šolc ◽  
Štefan Markulik ◽  
Eva Grambalová
Keyword(s):  
Experimental Data ◽  
Technological Process ◽  
Maximum Concentration ◽  
Statistical Processing ◽  
Experimental Results ◽  
Data Sets ◽  
Refractory Materials ◽  
Processing Data

In addressing issues related to technology or quality refractory products are among the supporting documents experimental results of the tests. These more or less extensive data sets characterize with some precision observed phenomenon, e.g. some physical or chemical quantity. The role of statistical processing of data from this perspective, the maximum concentration sometimes extremely abundant, but few clear set of experimental data and determine the "seriousness" of this file. When processing data it is to be noted that these characteristics are not fully observed variable, but only a selected part.

Experimental Investigation of Bicycle Frame FEA Models

2013 ◽  
Author(s):  
Paul Miles ◽  
Mark Archibald
Keyword(s):  
Stress State ◽  
Axial Stress ◽  
Experimental Results ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Fea Model ◽  
Bicycle Frame ◽  
Stress States ◽  
Von Mises ◽  
Fea Analysis

This study experimentally investigated pedal cycle frame loads and verified analytical load cases applied to vehicle design. The experimental results were compared with a Finite Element Analysis (FEA) model. The weight of the rider on the seat, road induced loads and vibrations, and the force the rider exerts on the pedals affect the stress state of the frame. Strain gauges were applied to two different frame models. Four different locations were tested on a monotube long-wheel base (LWB) recumbent frame and six locations on a standard upright Schwinn. The stress state was calculated from the raw strain data. Depending on the gauge being used, the results either indicated the von Mises stress or simply the axial stress. The different loading conditions tested were as follows: static, steady pedaling on smooth, mid-grade, and rough pavement, and hard acceleration on level ground and uphill. The static and hard acceleration cases were directly compared to the FEA model. The experimental results were comparable to the FEA analysis. The complexity of the load case, coupled with unknown actual loads, explains the larger differences between FEA and experimental results. Based on experimental results, the FEA model was refined, improving the agreement between model and experiment. The stress states of a bicycle frame were successfully found experimentally, being confirmed by multiple runs under each loading condition. Based on the agreement between the two methods, the use of FEA load cases to predict stresses in pedal cycle frames was verified.

INVESTIGATION ON THE STIFFNESS OF 3-HSS PARALLEL KINEMATIC MACHINE USING FINITE ELEMENT ANALYSIS

2002 ◽  
Vol 26 (3) ◽  
pp. 337-346 ◽  
Author(s):  
Lihua Zhou ◽  
Tian Huang ◽  
Hanfried Kerle
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Conceptual Design ◽  
Axial Stiffness ◽  
Parallel Kinematic Machine ◽  
Element Analysis ◽  
Fea Model ◽  
Parallel Kinematic ◽  
Good Agreement

A feasible way to estimate the stiffness of a 3-HSS parallel kinematic machine (PKM) by finite element analysis (FEA) is presented. Taking into consideration the base, columns, carriages struts and the mobile platform, a FEA model for the whole machine is established by solving such problems as match between different element types and simulation of moving components. Later on, this approach is applied to a particular 3-HSS PKM, Linapod, and used to steer the conceptual design of the machine. Furthermore, experiments are made on radial and axial stiffness. By comparison, the FE analytical results show good agreement with experimental data.

scholarly journals Prediction of Pressing Quality for Press-Fit Assembly Based on Press-Fit Curve and Maximum Press-Mounting Force

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Bo You ◽  
Zhifeng Lou ◽  
Yi Luo ◽  
Yang Xu ◽  
Xiaodong Wang
Keyword(s):  
Experimental Method ◽  
Maximum Deviation ◽  
Static Structure ◽  
Element Analysis ◽  
Press Fit ◽  
Fea Model ◽  
A Value ◽  
The Press ◽  
Ansys Workbench

In order to predict pressing quality of precision press-fit assembly, press-fit curves and maximum press-mounting force of press-fit assemblies were investigated by finite element analysis (FEA). The analysis was based on a 3D Solidworks model using the real dimensions of the microparts and the subsequent FEA model that was built using ANSYS Workbench. The press-fit process could thus be simulated on the basis of static structure analysis. To verify the FEA results, experiments were carried out using a press-mounting apparatus. The results show that the press-fit curves obtained by FEA agree closely with the curves obtained using the experimental method. In addition, the maximum press-mounting force calculated by FEA agrees with that obtained by the experimental method, with the maximum deviation being 4.6%, a value that can be tolerated. The comparison shows that the press-fit curve and max press-mounting force calculated by FEA can be used for predicting the pressing quality during precision press-fit assembly.

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

Tire Cornering Simulation Using an Explicit Finite Element Analysis Code

1998 ◽  
Vol 26 (2) ◽  
pp. 109-119 ◽  
Author(s):  
M. Koishi ◽  
K. Kabe ◽  
M. Shiratori
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Test System ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
Element Method

Abstract The finite element method has been used widely in tire engineering. Most tire simulations using the finite element method are static analyses, because tires are very complex nonlinear structures. Recently, transient phenomena have been studied with explicit finite element analysis codes. In this paper, the authors demonstrate the feasibility of tire cornering simulation using an explicit finite element code, PAM-SHOCK. First, we propose the cornering simulation using the explicit finite element analysis code. To demonstrate the efficiency of the proposed simulation, computed cornering forces for a 175SR14 tire are compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering forces agree well with experimental results. After that, parametric studies are conducted by using the proposed simulation.

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