scholarly journals A Data-Driven Learning Method for Constitutive Modeling: Application to Vascular Hyperelastic Soft Tissues

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2319 ◽  
Author(s):  
David González ◽  
Alberto García-González ◽  
Francisco Chinesta ◽  
Elías Cueto
Keyword(s):  
Constitutive Modeling ◽  
Soft Tissues ◽  
Topological Data Analysis ◽  
Basic Principles ◽  
Conservation Of Energy ◽  
Tissue Modeling ◽  
Analysis Techniques ◽  
Large Patient ◽  
True Shape ◽  
Production Of Entropy

We address the problem of machine learning of constitutive laws when large experimental deviations are present. This is particularly important in soft living tissue modeling, for instance, where large patient-dependent data is found. We focus on two aspects that complicate the problem, namely, the presence of an important dispersion in the experimental results and the need for a rigorous compliance to thermodynamic settings. To address these difficulties, we propose to use, respectively, Topological Data Analysis techniques and a regression over the so-called General Equation for the Nonequilibrium Reversible-Irreversible Coupling (GENERIC) formalism (M. Grmela and H. Ch. Oettinger, Dynamics and thermodynamics of complex fluids. I. Development of a general formalism. Phys. Rev. E 56, 6620, 1997). This allows us, on one hand, to unveil the true “shape” of the data and, on the other, to guarantee the fulfillment of basic principles such as the conservation of energy and the production of entropy as a consequence of viscous dissipation. Examples are provided over pseudo-experimental and experimental data that demonstrate the feasibility of the proposed approach.

Basic principles of surgical treatment of artificial pyoinflammatory diseases of soft tissues

2018 ◽  
pp. 44-46
Author(s):  
A.N. Koval ◽  
N.V. Tashkinov ◽  
G.G. Melkonyan ◽  
A.Y. Marochko ◽  
B.M. Kogut ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Soft Tissues ◽  
Basic Principles

Three-Dimensional Analysis Techniques—Part 3: Color-Coded System for Three-Dimensional Measurement of Bone and Ratio of Soft Tissue to Bone: The Analysis

1997 ◽  
Vol 34 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Andrew M. Mccance ◽  
James P. Moss ◽  
W. Rick Fright ◽  
Alf D. Linney
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Ct Scans ◽  
Dimensional Changes ◽  
Analysis Techniques ◽  
Dimensional Measurement ◽  
Three Dimensional Measurement ◽  
The Face ◽  
Bimaxillary Surgery

A new color-coded method of illustrating three-dimensional changes in the bone and the ratio of soft tissue to bone movement is described. The technique is illustrated by superimposing preoperative and 1-year postoperative CT scans of three patients following bimaxillary surgery. The method has proved to be a very simple, effective, and readily interpreted method of quantifying both bone and the ratio of movement of the overlying soft tissues across the face following surgery.

Material Properties Over-Estimated by Boundary Conditions in Biaxial Tension Can Be Corrected Using Finite Element Analysis

2012 ◽  
Author(s):  
Nathan T. Jacobs ◽  
Daniel H. Cortes ◽  
Spencer E. Szczesny ◽  
Edward J. Vresilovic ◽  
Dawn M. Elliott
Keyword(s):  
Material Properties ◽  
Experimental Approach ◽  
Soft Tissues ◽  
Biaxial Tension ◽  
Experimental Studies ◽  
Constitutive Relationship ◽  
Element Analysis ◽  
Tissue Modeling ◽  
In Situ Conditions

Tissue modeling requires an appropriate stress-strain constitutive relationship and a corresponding set of material properties. It is often the goal of experimental studies to determine these material properties. Uniaxial tension experiments are simple in experimental approach and the interpretation of results is straightforward, prompting its use in several studies. However, the freely contracting lateral edges observed in this loading modality do not mimic the in situ conditions of many fiber-reinforced soft tissues and the unconstrained fibers may also create errors.

scholarly journals A Derivation of the Main Relations of Nonequilibrium Thermodynamics

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Vladimir N. Pokrovskii
Keyword(s):  
Nonequilibrium Thermodynamics ◽  
Second Law Of Thermodynamics ◽  
Thermodynamic System ◽  
Internal Variables ◽  
Second Law ◽  
Basic Principles ◽  
First Law Of Thermodynamics ◽  
Sum Of Products ◽  
Thermodynamic Forces ◽  
Production Of Entropy

The principles of nonequilibrium thermodynamics are discussed, using the concept of internal variables that describe deviations of a thermodynamic system from the equilibrium state. While considering the first law of thermodynamics, work of internal variables is taken into account. It is shown that the requirement that the thermodynamic system cannot fulfil any work via internal variables is equivalent to the conventional formulation of the second law of thermodynamics. These statements, in line with the axioms introducing internal variables can be considered as basic principles of nonequilibrium thermodynamics. While considering stationary nonequilibrium situations close to equilibrium, it is shown that known linear parities between thermodynamic forces and fluxes and also the production of entropy, as a sum of products of thermodynamic forces and fluxes, are consequences of fundamental principles of thermodynamics.

scholarly journals Soft and Hard Tissue Management in Implant Therapy—Part II: Prosthetic Concepts

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Paolo Francesco Manicone ◽  
Luca Raffaelli ◽  
Marjan Ghassemian ◽  
Antonio D'Addona
Keyword(s):  
Soft Tissue ◽  
Treatment Planning ◽  
Early Treatment ◽  
Soft Tissues ◽  
Tissue Architecture ◽  
Hard Tissue ◽  
Tissue Modeling ◽  
Soft Tissue Profile ◽  
Implant Therapy ◽  
Soft Tissue Modeling

The ongoing pursuit of aesthetic excellence in the field of implant therapy has incorporated prosthetic concepts in the early treatment-planning phase, as well as the previously discussed surgical concepts. The literature has addressed these prosthetic and laboratory approaches required to enhance and perfect the soft and hard tissue management (SHTM). After surgically providing an acceptable hard tissue architecture and adequate timing of loading of the implant, the prosthetic phase is responsible for the soft tissue modeling, through correctly planned and executed procedures, which induce a satisfactory soft tissue profile by considering the microvasculature, the abutment connection and positioning, and the implementation of an adequate provisional phase. The objectives are the modeling of the soft tissues through the use of a conforming periorestorative interface which will produce desired and stable results.

Distributed Recommender Systems

2001 ◽  
pp. 372-393 ◽  
Author(s):  
Badrul M. Sarwar ◽  
Joseph A. Konstan ◽  
John T. Riedl
Keyword(s):  
Data Analysis ◽  
Real Time ◽  
Recommender Systems ◽  
Recommender System ◽  
Design Issues ◽  
Internet Commerce ◽  
Basic Principles ◽  
Analysis Techniques

In this chapter, we introduce the concepts of recommender systems as a very successful Internet commerce tool. Then, we describe the basic principles of recommender systems and carefully analyzes how these systems relate to other prevailing data-analysis techniques and how they are more suitable for providing real-time personalized recommendations for customers of Internet commerce. The following section depicts the importance of recommender systems and their strategies for improving sales. We then analyze the nature and necessity of recommender systems in future commerce applications and establish the need for distributing such services to make them widely available. Later we present a detailed taxonomy of distributed recommender system applications and three different implementation frameworks for providing distributed recommender system services for Internet commerce, we analyze some of the design issues as well.

The Coupled Thermal Mechanical Modeling of the Inertia Friction Welding Process for Inconel718

2011 ◽  
Vol 704-705 ◽  
pp. 710-716 ◽  
Author(s):  
Wen De Bu ◽  
Jin He Liu
Keyword(s):  
Friction Welding ◽  
Welding Process ◽  
Mechanical Analysis ◽  
Friction Torque ◽  
Interface Temperature ◽  
Deformation Pattern ◽  
Fe Model ◽  
Inertia Friction Welding ◽  
Conservation Of Energy ◽  
True Shape

In this paper, numerical modeling of inertia friction welding (IFW) for Inconel718 was performed using ABAQUS/Explicit with a 3D finite-element (FE) model and the coupled thermo-mechanical analysis. A new thermal input model has been deduced according to the characteristics of IFW and law of conservation of energy. The evolution of temperature field as well as the deformation pattern of the inertia welded joint has been predicted. It is shown that the interface temperature firstly increases rapidly to about 1100 °C within 3 s and then increases slowly. The energy input rate at the interface during the IFW process is closely related to the rotational speed and friction torque of flywheels. The temperature distribution at the interface is very inhomogeneous especially at the initial stage and finally tends to become uniform with the increase of time. Consequently, the flash start to appear as the interface temperature becomes homogeneous relatively and the plastic flow of metal at the interface happens. The verifying trial was carried out and the predicted temperature was compared with the experimental data measured by means of thermocouples. The shape of flash in simulation result was contrasted with the true shape of specimen under the same welding conditions. It is noted that the simulation results agrees well with the experimental results.

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