A Novel Tactile Sensor Design for Stiffness Detection of Soft Tissues

2010 ◽  
Author(s):  
Ahmed M. R. Fath El Bab ◽  
Khaled I. E. Ahmed
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Simulation Model ◽  
Soft Tissues ◽  
Tactile Sensor ◽  
Sensor Design ◽  
Contact Conditions ◽  
Sensor Performance ◽  
Element Simulation ◽  
Different Tissues

A novel tactile sensor design for stiffness detection of soft tissues is proposed aiming to get output readings uninfluenced of the contact conditions. The sensor principle is based on the concept of applying two springs, with considerably different stiffnesses, to soft tissue for stiffness detection. The sensor consists of two coaxial diaphragms with contact mesa to work as two different springs. The sensor mesas are designed in circular shape to compensate the error caused by the pushing distances between the sensor and the soft tissue. A finite element simulation model is developed to investigate the sensor performance. The results show that the sensor can successfully distinguish between different tissues with close stiffnesses independently of the pushing distance between the sensor and the tissue. Moreover the sensor shows good output linearity when measure different tissue stiffnesses.

Research on Surface Roughness of Supersonic Vibration Auxiliary Side Milling for Titanium Alloy

2021 ◽  
Author(s):  
XueTao Wei ◽  
caixue yue ◽  
DeSheng Hu ◽  
XianLi Liu ◽  
YunPeng Ding ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Prediction Model ◽  
Simulation Model ◽  
Finite Element Simulation ◽  
Simulation Software ◽  
Surface Roughness Prediction ◽  
Contour Shape ◽  
Element Simulation ◽  
Roughness Prediction

Abstract The processed surface contour shape is extracted with the finite element simulation software, and the difference value of contour shape change is used as the parameters of balancing surface roughness to construct the infinitesimal element cutting finite element model of supersonic vibration milling in cutting stability domain. The surface roughness trial scheme is designed in the central composite test design method to analyze the surface roughness test result in the response surface methodology. The surface roughness prediction model is established and optimized. Finally, the finite element simulation model and surface roughness prediction model are verified and analyzed through experiment. The research results show that, compared with the experiment results, the maximum error of finite element simulation model and surface roughness prediction model is 30.9% and12.3%, respectively. So, the model in this paper is accurate and will provide the theoretical basis for optimization study of auxiliary milling process of supersonic vibration.

scholarly journals Key considerations for finite element modelling of the residuum–prosthetic socket interface

2020 ◽  
pp. 030936462096778
Author(s):  
JW Steer ◽  
PR Worsley ◽  
M Browne ◽  
Alex Dickinson
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Finite Element Modelling ◽  
Soft Tissues ◽  
Shear Stresses ◽  
Material Models ◽  
Element Modelling ◽  
Prosthetic Socket ◽  
Highly Nonlinear ◽  
Socket Interface

Background: Finite element modelling has long been proposed to support prosthetic socket design. However, there is minimal detail in the literature to inform practice in developing and interpreting these complex, highly nonlinear models. Objectives: To identify best practice recommendations for finite element modelling of lower limb prosthetics, considering key modelling approaches and inputs. Study design: Computational modelling. Methods: This study developed a parametric finite element model using magnetic resonance imaging data from a person with transtibial amputation. Comparative analyses were performed considering socket loading methods, socket–residuum interface parameters and soft tissue material models from the literature, to quantify their effect on the residuum’s biomechanical response to a range of parameterised socket designs. Results: These variables had a marked impact on the finite element model’s predictions for limb–socket interface pressure and soft tissue shear distribution. Conclusions: All modelling decisions should be justified biomechanically and clinically. In order to represent the prosthetic loading scenario in silico, researchers should (1) consider the effects of donning and interface friction to capture the generated soft tissue shear stresses, (2) use representative stiffness hyperelastic material models for soft tissues when using strain to predict injury and (3) interrogate models comparatively, against a clinically-used control.

Integrated System for Soft Tissue Dynamic Simulation

2010 ◽  
Author(s):  
Xiaodong Zhao ◽  
Baoxiang Shan ◽  
Assimina A. Pelegri
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
State Space ◽  
Soft Tissues ◽  
Mathematical Formulation ◽  
State Space Model ◽  
Order Reduction ◽  
Integrated System ◽  
Space Model ◽  
Tissue Models

An integrated system is built to model and simulate the dynamic response of soft tissues. The mathematical formulation employs finite element and model order reduction approaches to develop a state space model for soft tissues that allows for time-efficient numerical analysis. The stimulus device and signal processing routines are built in Matlab/Simulink and then integrated with the finite element state space model. This integrated system facilitates expeditious numerical evaluation of different soft tissue models subjected to dynamic excitation. It further elucidates the effect of different stimulus sources, as well as relative influences of different sources of uncertainty.

Finite Element Simulation and Experiment of Mechanical Expanding for Longitudinal Welded Pipe

2015 ◽  
Vol 727-728 ◽  
pp. 493-496
Author(s):  
Yun Feng Yao ◽  
Ying Gao ◽  
Jun Xia Li ◽  
Shuang Jie Zhang ◽  
Tao Han
Keyword(s):  
Finite Element ◽  
Simulation Model ◽  
Finite Element Simulation ◽  
Nonlinear Finite Element ◽  
Two Dimensional ◽  
Finite Element Software ◽  
Element Simulation ◽  
Dimensional Finite Element ◽  
Simulation And Experiment ◽  
Welded Pipe

A two-dimensional finite element simulation model of longitudinal welded pipe is established by the nonlinear finite element software ABAQUS. Testing enlargement mould is used for the expanding experiments for the welded pipe under the laboratory condition. The expanding force, ovality and the shape are simulated and measured. Comparing the experimental and the simulated results, the values are fitted well.

scholarly journals The Finite Element Simulation of the Upper Airway of Patients with Moderate and Severe Obstructive Sleep Apnea Hypopnea Syndrome

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Huiping Luo ◽  
Austin Scholp ◽  
Jack J. Jiang
Keyword(s):  
Finite Element ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Soft Tissue ◽  
Soft Tissues ◽  
Upper Airway ◽  
Model Parameters ◽  
Obstructive Sleep ◽  
Hypopnea Syndrome ◽  
Fluid Solid Interaction

Objectives. To investigate the snoring modes of patients with Obstructive Sleep Apnea Hypopnea Syndrome and to discover the main sources of snoring in soft tissue vibrations. Methods. A three-dimensional finite element model was developed with SolidEdge to simulate the human upper airway. The inherent modal simulation was conducted to obtain the frequencies and the corresponding shapes of the soft tissue vibrations. The respiration process was simulated with the fluid-solid interaction method through ANSYS. Results. The first 6 orders of modal vibration were 12 Hz, 18 Hz, 21 Hz, 22 Hz, 36 Hz, and 39 Hz. Frequencies of modes 1, 2, 4, and 5 were from tongue vibrations. Frequencies of modes 3 and 6 were from soft palate vibrations. Steady pressure distribution and air distribution lines in the upper airway were shown clearly in the fluid-solid interaction simulation results. Conclusions. We were able to observe the vibrations of soft tissue and the modeled airflow by applying the finite element methods. Future studies could focus on improving the soft tissues vibration compliances by adjusting the model parameters. Additionally, more attention should be paid to vibrational components below 20 Hz when performing an acoustic analysis of human snore sounds due to the presence of these frequencies in this model.

Analysis and Simulation on the Influencing Factors of Braking Force for Permanent Magnetic Brake

2013 ◽  
Vol 278-280 ◽  
pp. 278-281 ◽  
Author(s):  
Ming Yao ◽  
Liang Wang
Keyword(s):  
Finite Element ◽  
Simulation Model ◽  
Finite Element Simulation ◽  
Influencing Factors ◽  
Great Influence ◽  
Element Simulation ◽  
Working Principle ◽  
Main Factors ◽  
Braking Force ◽  
Theory Formula

The structure and working principle of permanent magnetic brake were introduced and the main factors of influencing braking ability of the permanent magnetic brake were analyzed with theory formula. By using of software as Ansoft, an finite element simulation model for magnetic brake were built up, and compare simulate value with theoretical one express that they have better consistency. Based on the simulation model, influencing factors of the braking force about permanent magnetic brake were analyzed, and the simulate results express that the height of gap between brake and track has a great influence on the braking force, so it must pay much more attention on brake design.

Finite Element Simulation Model for High Temperature 4H-SiC Devices

2011 ◽  
Vol 413 ◽  
pp. 229-234 ◽  
Author(s):  
Hassan Habib ◽  
Nicolas G. Wright ◽  
Alton B. Horsfall
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Simulation Model ◽  
Finite Element Simulation ◽  
Computer Aided Design ◽  
High Performance ◽  
Extreme Environments ◽  
Simulation Models ◽  
Trade Offs ◽  
Element Simulation

In the last decade, or so, many prototype Silicon Carbide devices and circuits have been demonstrated which have surpassed the performance of Silicon for the ability to function in extreme environments. However, the commercialisation of SiC technology now demands high performance and energy efficient miniaturised devices and circuits which can operate on the limited power resources available in harsh and hot hostile environments. This leads to refining, experimenting and perhaps re-designing devices which can rightly claim their share in the current Si dominant market. Consequently, there is a need for accurate simulation models for device engineers to understand device behaviour, examine performance trade-offs and verify the manufacturability of the design. This paper reports the first comprehensive study on the development and validation of high temperature 4H-SiC Technology Computer Aided Design (TCAD) Finite Element simulation model for low power applications. The model is based on 4H-SiC physical and material properties and is validated by high temperature 4H-SiC lateral JFET data, fabricated and characterised by our group at Newcastle University.

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