Modelling Sheave Elasticity in CVT Drives

2005 ◽  
Author(s):  
Wolfram Lebrecht ◽  
Heinz Ulbrich ◽  
Friedrich Pfeiffer
Keyword(s):  
Numerical Simulations ◽  
Mechanical Behaviour ◽  
Strain Energy ◽  
Three Dimensional ◽  
Simulation Models ◽  
Industrial Applications ◽  
Belt Drives ◽  
Different Types ◽  
Force Element ◽  
Account Due

This contribution presents the modelling of chain and belt CVT drives used in numerical simulations, under special consideration of the elasticity of the pulley sheaves. The system is subdivided into the pulleys, the power transmitting chain or belt and different types of contacts. Since the deformation of the CVT is of major importance for the mechanical behaviour, the elasticity of the colliding bodies has to be taken into account. Due to elasticity and clearance of the shaft-to-collar connection the pulley sheaves tilt. This effect is modelled by a force element. Furthermore as a consequence of the asymmetrical loading, the elastic sheaves deform. Therefore different approaches exist to take this into account, in which the most efficient way is the use of Castigliano’s Strain Energy Theorem. The system contains a large number of contacts. First of all there are three dimensional contacts between the pulley sheaves and the belt or chain elements. In case of belt systems there are further contacts between two adjacent elements, between elements and rings and between two adjacent rings. There exist simulation models for both types of CVTs (chain and belt drives), which are used in industrial applications.

Three-Dimensional Fractional Derivative Models for Finite Deformation

2011 ◽  
Author(s):  
Masataka Fukunaga ◽  
Nobuyuki Shimizu
Keyword(s):  
Fractional Derivative ◽  
Stress Tensor ◽  
Memory Effect ◽  
Strain Energy ◽  
Three Dimensional ◽  
Strain Energy Function ◽  
Stress Strain ◽  
Different Types ◽  
Strain Tensors ◽  
The Continuum

Fractional derivative stress-strain relations are derived for compressible viscoelastic materials based on the continuum mechanics. Several types of stress tensor and strain tensors are specified to describe the dynamics of continuous media. Consequently there are many equivalent expressions of stress-strain relations. If memory effect is not taken into account, these relations are equivalently transformed from one to another by suitable tensor operations. However, if memory effect is included in the mechanics of the materials, different types of stress-strain relations can be derived depending on the choice of the type of stress tensor, or equivalently the choice of the strain energy function. In this paper, several types of fractional derivative stress-strain relations are proposed.

Modeling of Looping Behavior in a Flexible Instrument Using a Bélzier Curve

2021 ◽  
Author(s):  
Shobhit Singhal ◽  
Jitendra P. Khatait
Keyword(s):  
Strain Energy ◽  
Dimensional Space ◽  
Plane Deformation ◽  
Three Dimensional ◽  
Industrial Applications ◽  
Flexible Instrument ◽  
Out Of Plane ◽  
Minimum Strain Energy ◽  
And Control ◽  
Three Dimensional Space

Abstract Flexible medical instruments undergo looping during insertion and navigation inside the human body. It makes the control of the distal end difficult and raises safety concerns. This paper proposes the minimum strain energy concept to get the deformed shape of a flexible instrument in three-dimensional space. A B\'{e}zier curve is used to define the trajectory of the deformed shape under different loading conditions and constraints. Looping behavior is studied for different end shortening conditions. The effect of end twist on looping behavior is studied. It is observed that end twist leads to early onset of out of plane deformation leading to looping. The strain energy plot gives an insight into the behavior of these instruments with respect to end shortening and twist. The strain energy plot shows the minimum value for $2\pi$ end twist. Therefore, the instrument tends to go for looping if the end twist is present. Force and torque characteristics are obtained which will lead to the design and control of these instruments. Force and torque plots show negative stiffness when the instrument is going for looping. The un-looping phenomenon is also discussed and a strategy is proposed to mitigate looping. The proposed modeling approach can be utilized to address the complex behavior of a flexible instrument in medical as well as in other industrial applications. The insight developed will help in designing and developing control for safe and reliable usage of flexible instruments in various domains.

scholarly journals Time temperature equivalence for a mineral filled polymer for automotive applications

2018 ◽  
Vol 183 ◽  
pp. 04011
Author(s):  
Vincent Dorleans ◽  
Franck Lauro ◽  
Rémi Delille ◽  
Sylvain Treutenaere ◽  
Delphine Notta-Cuvier ◽  
...  
Keyword(s):  
Strain Rate ◽  
Experimental Research ◽  
Mechanical Behaviour ◽  
High Strain ◽  
Industrial Applications ◽  
Strain Rates ◽  
Automotive Applications ◽  
Complete Variety ◽  
Dynamic Loadings ◽  
Different Types

Polymers are currently used in several industrial applications such as the interior components of the vehicle. We find them for example in the design of dashboards or door panels. These materials may be subjected to different types of load like the temperature variation or high strain rates due to crash impact. It is therefore necessary to well understand and to anticipate the complex mechanical behaviour of the polymers. This paper describes the results of experimental research about the dependence between the strain rate and the temperature. The main objective is to be able to model the complete variety of the behaviour in order to predict the risk of failure under dynamic loadings. The material chosen for this study is a copolymer propylene ethylene mineral (talc) filled 15% impact modified.

Flow Computations of Rib-Roughened Cooling Channels With RANS and Scale Resolving Simulation Models

2017 ◽  
Author(s):  
İlhan Görgülü ◽  
Ender Hepkaya
Keyword(s):  
Numerical Simulations ◽  
Experimental Studies ◽  
Flow Simulation ◽  
Turbulence Models ◽  
Simulation Models ◽  
Reynolds Stress Model ◽  
Industrial Applications ◽  
Test Case ◽  
Detached Eddy Simulation ◽  
Eddy Simulation

In this research, experimental studies conducted by Casarsa [1] were used as test case to validate flow simulation methods. In the numerical simulations, four RANS turbulence models (k-ε, k-ω, V2-f and Reynolds Stress Model) and a URANS model which are widely used in industrial applications were employed for preliminary analyses. In addition, Scale-Adaptive Simulation (SAS), Detached Eddy Simulation (DES) and Large Eddy Simulation (LES) models are conducted to examine the capabilities of Scale Resolving Simulation (SRS) models. All numerical simulations were performed on two different grid resolutions. Relevance of the grid resolutions to the applied SRS methodologies have been assessed both with crude estimations obtained from the RANS simulations and examination of LES solutions. Findings were presented at various parallel and perpendicular planes with respect to the side walls and different over and inter-rib space locations in the form of mean and root mean square (rms) velocity profiles. In all comparisons, SRS results revealed an inarguable superiority over RANS models as expected. Among the SRS models, SAS model has been considered as the most promising industrial purpose model because of providing similar quality results by allowing higher time steps and coarser grid resolutions.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

A Study on Utilization of Three-Dimensional Sensor Lip Image for Developing a Pronunciation Recognition System

2019 ◽  
Vol 63 (5) ◽  
pp. 50402-1-50402-9 ◽  
Author(s):  
Ing-Jr Ding ◽  
Chong-Min Ruan
Keyword(s):  
Principal Component Analysis ◽  
Automatic Speech Recognition ◽  
Feature Fusion ◽  
Three Dimensional ◽  
Principal Component ◽  
Recognition System ◽  
Geometrical Characteristics ◽  
3D Geometry ◽  
Different Types ◽  
The Disabled

Abstract The acoustic-based automatic speech recognition (ASR) technique has been a matured technique and widely seen to be used in numerous applications. However, acoustic-based ASR will not maintain a standard performance for the disabled group with an abnormal face, that is atypical eye or mouth geometrical characteristics. For governing this problem, this article develops a three-dimensional (3D) sensor lip image based pronunciation recognition system where the 3D sensor is efficiently used to acquire the action variations of the lip shapes of the pronunciation action from a speaker. In this work, two different types of 3D lip features for pronunciation recognition are presented, 3D-(x, y, z) coordinate lip feature and 3D geometry lip feature parameters. For the 3D-(x, y, z) coordinate lip feature design, 18 location points, each of which has 3D-sized coordinates, around the outer and inner lips are properly defined. In the design of 3D geometry lip features, eight types of features considering the geometrical space characteristics of the inner lip are developed. In addition, feature fusion to combine both 3D-(x, y, z) coordinate and 3D geometry lip features is further considered. The presented 3D sensor lip image based feature evaluated the performance and effectiveness using the principal component analysis based classification calculation approach. Experimental results on pronunciation recognition of two different datasets, Mandarin syllables and Mandarin phrases, demonstrate the competitive performance of the presented 3D sensor lip image based pronunciation recognition system.

Simulating Self-Regeneration and Self-Replication Processes Using Movable Cellular Automata with a Mutual Equilibrium Neighborhood

2020 ◽  
Vol 29 (4) ◽  
pp. 741-757
Author(s):  
Kateryna Hazdiuk ◽  
◽  
Volodymyr Zhikharevich ◽  
Serhiy Ostapov ◽  
◽  
...  
Keyword(s):  
Cellular Automata ◽  
Cellular Automaton ◽  
Three Dimensional ◽  
Computer Models ◽  
The Self ◽  
Model Construction ◽  
Natural Phenomena ◽  
Different Types ◽  
Movable Cellular Automata ◽  
Self Replication

This paper deals with the issue of model construction of the self-regeneration and self-replication processes using movable cellular automata (MCAs). The rules of cellular automaton (CA) interactions are found according to the concept of equilibrium neighborhood. The method is implemented by establishing these rules between different types of cellular automata (CAs). Several models for two- and three-dimensional cases are described, which depict both stable and unstable structures. As a result, computer models imitating such natural phenomena as self-replication and self-regeneration are obtained and graphically presented.

Geological Field Sketches and Illustrations

2019 ◽  
Author(s):  
Matthew J. Genge
Keyword(s):  
Cross Sections ◽  
Earth Science ◽  
Three Dimensional ◽  
Worked Examples ◽  
Scientific Publications ◽  
Thin Sections ◽  
Geological Features ◽  
Different Types ◽  
The Subject

Drawings, illustrations, and field sketches play an important role in Earth Science since they are used to record field observations, develop interpretations, and communicate results in reports and scientific publications. Drawing geology in the field furthermore facilitates observation and maximizes the value of fieldwork. Every geologist, whether a student, academic, professional, or amateur enthusiast, will benefit from the ability to draw geological features accurately. This book describes how and what to draw in geology. Essential drawing techniques, together with practical advice in creating high quality diagrams, are described the opening chapters. How to draw different types of geology, including faults, folds, metamorphic rocks, sedimentary rocks, igneous rocks, and fossils, are the subjects of separate chapters, and include descriptions of what are the important features to draw and describe. Different types of sketch, such as drawings of three-dimensional outcrops, landscapes, thin-sections, and hand-specimens of rocks, crystals, and minerals, are discussed. The methods used to create technical diagrams such as geological maps and cross-sections are also covered. Finally, modern techniques in the acquisition and recording of field data, including photogrammetry and aerial surveys, and digital methods of illustration, are the subject of the final chapter of the book. Throughout, worked examples of field sketches and illustrations are provided as well as descriptions of the common mistakes to be avoided.

An isotropic elasto-damage-plastic micromechanical framework of innovative pothole patching materials featuring high-toughness, low-viscosity nanomolecular resin

2021 ◽  
pp. 105678952110286
Author(s):  
H Zhang ◽  
J Woody Ju ◽  
WL Zhu ◽  
KY Yuan
Keyword(s):  
Strain Energy ◽  
Three Dimensional ◽  
Elastic Strain Energy ◽  
Companion Paper ◽  
Computational Algorithms ◽  
Mechanical Behaviors ◽  
High Toughness ◽  
Low Viscosity ◽  
Innovative Materials ◽  
Continuum Thermodynamic

In a recent companion paper, a three-dimensional isotropic elastic micromechanical framework was developed to predict the mechanical behaviors of the innovative asphalt patching materials reinforced with a high-toughness, low-viscosity nanomolecular resin, dicyclopentadiene (DCPD), under the splitting tension test (ASTM D6931). By taking advantage of the previously proposed isotropic elastic-damage framework and considering the plastic behaviors of asphalt mastic, a class of elasto-damage-plastic model, based on a continuum thermodynamic framework, is proposed within an initial elastic strain energy-based formulation to predict the behaviors of the innovative materials more accurately. Specifically, the governing damage evolution is characterized through the effective stress concept in conjunction with the hypothesis of strain equivalence; the plastic flow is introduced by means of an additive split of the stress tensor. Corresponding computational algorithms are implemented into three-dimensional finite elements numerical simulations, and the outcomes are systemically compared with suitably designed experimental results.

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