A device for mimicking the contact force/contact area relationship of different materials with applications to softness rendering

2013 ◽  
Author(s):  
Alessandro Serio ◽  
Matteo Bianchi ◽  
Antonio Bicchi
Keyword(s):  
Contact Force ◽  
Contact Area ◽  
Force Contact ◽  
Relationship Of

scholarly journals Relationship of Catheter Contact Angle and Contact Force with Contact Area on the Surface of Heart Muscle Tissue in Cardiac Catheter Ablation

2021 ◽  
Author(s):  
Kriengsak Masnok ◽  
Nobuo Watanabe
Keyword(s):  
Contact Angle ◽  
Catheter Ablation ◽  
Contact Force ◽  
Contact Area ◽  
Heart Muscle ◽  
Contact Angles ◽  
Contact Forces ◽  
Logarithmic Function ◽  
Experimental Procedure ◽  
Relationship Of

Abstract Purpose The aims of this study were to develop an experimental procedure for setting the catheter angle with respect to the surface of the heart muscle and the catheter contact force and to investigate the catheter contact area on the heart muscle as a function of catheter contact angle and force. Methods Visualization tests were performed for 5 contact angles (0°, 30°, 45°, 60°, and 90°) and 8 contact forces (2, 4, 6, 10, 15, 20, 30, and 40 gf). Each experiment was repeated 6 times with 2 different commercially available catheter tips. Results The morphology of the contact area was classified into rectangular, circular, ellipsoidal, and semi-ellipsoidal. The correlation between contact force and contact area was a logarithmic function; increasing contact force was associated with increased contact area. At the same contact force, the correlation between contact angle and contact area was inverse; decreasing contact angle was associated with a corresponding increase in contact area. Conclusion Both the catheter contact angle and contact force substantially impact the contact area and morphology in catheter ablation procedures.

Surface fractal topography-based contact stiffness determination of spindle–toolholder joint

2015 ◽  
Vol 230 (4) ◽  
pp. 602-610 ◽  
Author(s):  
Yongsheng Zhao ◽  
Xiaolei Song ◽  
Ligang Cai ◽  
Zhifeng Liu ◽  
Qiang Cheng
Keyword(s):  
Contact Force ◽  
Contact Area ◽  
High Speed ◽  
Contact Stiffness ◽  
Fractal Theory ◽  
Contact Model ◽  
Real Contact Area ◽  
Real Contact ◽  
Fractal Parameters ◽  
Relationship Of

Accurate modeling of contact stiffness is crucial in predicting the dynamic behavior and chatter vibration of spindle–toolholder system for high-speed machining centers. This paper presents a fractal theory-based contact model of spindle–toolholder joint to obtain the contact stiffness and its real contact area. Topography of the contact surfaces of spindle–toolholder joint is fractal featured and determined by fractal parameters. Asperities in micro-scale are considered as elastic or plastic deformation. Then, the contact stiffness, the real contact area, the elastic contact force, and the plastic contact force of the whole contact surface are calculated by integrating the micro asperities. The relationship of the contact stiffness and the drawbar force follows a power law, in which the power index is determined by the fractal parameters. Experiments are conducted to verify the efficiency of the proposed model. The results from the fractal contact model of spindle–toolholder joint have good agreement with those of experiments.

Analysis of a Ball Bearing With Waviness Considering the Centrifugal Force and Gyroscopic Moment of the Ball

2003 ◽  
Vol 125 (3) ◽  
pp. 487-498 ◽  
Author(s):  
G. H. Jang ◽  
S. W. Jeong
Keyword(s):  
Centrifugal Force ◽  
Contact Force ◽  
Ball Bearing ◽  
Vibration Frequencies ◽  
Governing Equations ◽  
Equilibrium Equations ◽  
Gyroscopic Moment ◽  
Rolling Elements ◽  
Force Contact ◽  
Force Displacement

This research presents an analytical method to calculate the characteristics of the ball bearing under the effect of the waviness in its rolling elements and the centrifugal force and gyroscopic moment of ball. The waviness of rolling elements is modeled by using sinusoidal function, and the centrifugal force and gyroscopic. moment of ball are included in the kinematic constraints and force equilibrium equations to produce the nonlinear governing equations. To improve the convergence of the numerical solution of the nonlinear governing equations, it includes the derivatives of the gyroscopic moment and load-deflection constant of each race in the Newton-Raphson formulation. The accuracy of this research is validated by comparing with the prior research, i.e., (i) the contact force, contact angle in case of considering only the centrifugal force and gyroscopic moment of ball, and (ii) the contact force and vibration frequencies in case of considering only the waviness, respectively. It investigates the stiffness, contact force, displacement and vibration frequencies of the ball bearing, considering not only the centrifugal force and gyroscopic moment of ball but also the waviness of the rolling elements.

scholarly journals Short-term effects of oral appliances with equal bite-raising distance but with varying protrusions on occlusal force, contact area and load center

2008 ◽  
Vol 50 (3) ◽  
pp. 253-258
Author(s):  
Kuniko Saito ◽  
Takayuki Ikeda ◽  
Nobuhito Gionhaku ◽  
Toshimitsu Iinuma ◽  
Jin Sato ◽  
...  
Keyword(s):  
Contact Area ◽  
Oral Appliances ◽  
Short Term ◽  
Occlusal Force ◽  
Force Contact ◽  
Load Center ◽  
Short Term Effects

Determination of the Interference Geometry Between Two Convex Objects

2006 ◽  
Author(s):  
Lianzhen Luo ◽  
Meyer Nahon
Keyword(s):  
Contact Force ◽  
Contact Area ◽  
Contact Dynamics ◽  
Continuous Contact ◽  
Application Point ◽  
Haptic Interactions ◽  
Fitting Method ◽  
Best Fitting ◽  
Arbitrary Objects

The determination of the interference geometry between two arbitrary objects is an essential problem encountered in the simulation of continuous contact dynamics and haptic interactions. In these applications, with known material properties, the interbody contact force is only a function of the interference geometry between two objects. Here a theoretical basis and algorithms for the calculation of the interference geometry, such as overlap region, contact area and normal, and interference volume, are presented. Two methods to obtain the contact area and normal are analyzed: an area-weighted method and a best-fitting method. The geometric properties of the area-weighted method are presented and the degenerate cases related to both methods are discussed. Methods to calculate the application point of an interbody contact force are discussed. Some numerical simulation results are presented based on the implementation of the geometric algorithms, which are verified by comparison with hand calculation. The continuity of contact normal and its application point are demonstrated for a case in which the contacting objects smoothly move with respect to each other in the simulation.

scholarly journals A Finite Element-Based Elastic-Plastic Model for the Contact of Rough Surfaces

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Ali Sepehri ◽  
Kambiz Farhang
Keyword(s):  
Finite Element ◽  
Contact Force ◽  
Contact Area ◽  
Rough Surfaces ◽  
Constitutive Relations ◽  
Element Model ◽  
Tangential Component ◽  
Asperity Contact ◽  
Elastic Plastic ◽  
Force Components

Three-dimensional elastic-plastic contact of two nominally flat rough surfaces is considered. Equations governing the shoulder-shoulder contact of asperities are derived based on the asperity constitutive relations from a finite element model of the elastic-plastic interaction proposed by Kogut and Etsion (2002), in which asperity scale constitutive relations are derived using piecewise approximate functions. An analytical fusion technique is developed to combine the piecewise asperity level constitutive relations. Shoulder-shoulder asperity contact yields a slanted contact force consisting of two components, one in the normal direction and a half-plane tangential component. Statistical summation of the asperity level contact force components and asperity level contact area results in the total contact force and total contact area formulae between two rough surfaces. Approximate equations are developed in closed form for contact force components and contact area.

Identification of Contact Conditions from Contact Force and Moment - Experimental Verification in Effective Sensing Strategy -

2009 ◽  
Vol 21 (2) ◽  
pp. 236-244 ◽  
Author(s):  
Takayoshi Yamada ◽  
◽  
Tetsuya Mouri ◽  
Akira Tanaka ◽  
Nobuharu Mimura ◽  
...  
Keyword(s):  
Contact Force ◽  
Contact Line ◽  
Contact Conditions ◽  
Contact Type ◽  
Degree Of Separation ◽  
Direction Of Movement ◽  
Force Contact ◽  
The Difference ◽  
Contact Position ◽  
Small Eigenvalues

This paper discusses an effective sensing strategy for identification of contact conditions by using experiments. The contact conditions include contact position, contact force, contact type, direction of contact normal, and direction of contact line. To distinguish contact type more quickly and accurately, we must raise the degree of separation of large and small eigenvalues of a covariance matrix for estimating contact moment. Firstly, several sensing strategies are investigated through experiments. The difference of these strategies is the origin and direction of movement because the contact moment, which expresses the characteristic of contact type, is generated at a contact frame. Secondly, a more effective sensing movement is suggested from experimental results. Finally, it is pointed out that these strategies are related to sensing movement by a human being.

Evaluation of contact area and contact force between coil and cerebral aneurysm model

2019 ◽  
Vol 2019.32 (0) ◽  
pp. 2G31
Author(s):  
Yuta IKEDA ◽  
Kazuto Takashima ◽  
Kiyoshi YOSHINAKA ◽  
Kaihong YU ◽  
Makoto OHTA ◽  
...  
Keyword(s):  
Cerebral Aneurysm ◽  
Contact Force ◽  
Contact Area ◽  
Aneurysm Model

scholarly journals Characterization of the Resistance and Force of a Carbon Nanotube/Metal Side Contact by Nanomanipulation

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ning Yu ◽  
Masahiro Nakajima ◽  
Qing Shi ◽  
Zhan Yang ◽  
Huaping Wang ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Contact Force ◽  
Contact Area ◽  
Field Effect Transistors ◽  
Influence Factors ◽  
Contact Length ◽  
Before And After ◽  
Negative Exponential ◽  
Good Agreement

A high contact resistance restricts the application of carbon nanotubes (CNTs) in fabrication of field-effect transistors (FETs). Thus, it is important to decrease the contact resistance and investigate the critical influence factors such as the contact length and contact force. This study uses nanomanipulation to characterize both the resistance and the force at a CNT/Au side-contact interface inside a scanning electron microscopy (SEM). Two-terminal CNT manipulation methods, and models for calculating the resistance and force at contact area, are proposed to guide the measurement experiments of a total resistance and a cantilever’s elastic deformation. The experimental results suggest that the contact resistance of CNT/Au interface is large (189.5 kΩ) when the van der Waals force (282.1 nN) dominates the contact force at the interface. Electron-beam-induced deposition (EBID) is then carried out to decrease the contact resistance. After depositing seven EBID points, the resistance is decreased to 7.5 kΩ, and the force increases to 1339.8 nN at least. The resistance and force at the contact area where CNT was fixed exhibit a negative exponential correlation before and after EBID. The good agreement of this correlation with previous reports validates the proposed robotic system and methods for characterizing the contact resistance and force.

Grasping Contact Analysis of Viscoelastic Materials With Applications in Minimally Invasive Surgery

2006 ◽  
Author(s):  
Ali Bonakdar ◽  
Javad Dargahi ◽  
Rama Bhat
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Closed Form ◽  
Contact Force ◽  
Invasive Surgery ◽  
Contact Area ◽  
Biological Tissues ◽  
Closed Form Expression ◽  
Viscoelastic Materials ◽  
Form Analysis

This paper presents a method to determine the contact force and pressure on the surface of viscoelastic objects grasped by an endoscopic grasper, used in Minimally Invasive Surgery (MIS). Normally, an endoscopic grasper is corrugated (teeth-like) in order to grasp slippery tissues. It is highly important to avoid damage to the tissues during grasping and manipulation in endoscopic surgery. Therefore, it is essential to determine the exact contact force on the surface of the tissue. To this end, initially a comprehensive closed form analysis of grasping contact force and pressure on elastic and particularly viscoelastic materials which have similar behavior as that of biological tissues is studied. The behavior of a rigid grasper with wedge-like teeth, when pressed into a delayed elasticity material is being examined. Initially, a single wedge penetrating into a solid is studied and then is extended to the grasper. The elastic wedge indentation is the basis of this study and the effects of time are included in the equations by considering the corresponding integral operator from viscoelastic stress-stain relations. Under the action of a constant normal load, the penetration of the indenter and the contact area will change. In this research, the variation of the contact area with time and the grasping contact force is studied. The results of this study which provides a closed form expression for grasping contact force and contact area are compared with those from elastic analysis.

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