scholarly journals Line-Symmetric Motion Generators

2018 ◽  
pp. 347-355
Author(s):  
Yuanqing Wu ◽  
Marco Carricato
Keyword(s):  
Symmetric Motion

scholarly journals Kinetic Analysis of Water Fitness Exercises: Contributions for Strength Development

2019 ◽  
Vol 16 (19) ◽  
pp. 3784 ◽  
Author(s):  
Santos ◽  
Rama ◽  
Marinho ◽  
Barbosa ◽  
Costa
Keyword(s):  
Upper Limb ◽  
Force Production ◽  
Peak Force ◽  
Strength Development ◽  
Isokinetic Dynamometer ◽  
Symmetric Motion ◽  
Pressure System ◽  
Dry Land ◽  
Force Variation ◽  
Selection Of

The evaluation of propulsive forces in water allows the selection of the most appropriate strategies to develop strength during water fitness sessions. The aim of this study was threefold: (i) to analyze the rate of force production; (ii) to analyze the rate of force variation; and (iii) to compare limbs’ symmetry in two water fitness exercises. Twenty-two young health subjects (age: 21.23 ± 1.51 years old, body mass: 67.04 ± 9.31 kg, and height: 166.36 ± 8.01 cm) performed incremental protocols of horizontal adduction (HA) and rocking horse (RHadd), from 105 until 150 b·min–1. Data acquisition required an isokinetic dynamometer and a differential pressure system that allowed the assessment of (a) isometric peak force of dominant upper limb (IsometricFD); (b) propulsive peak force of dominant upper limb (PropulsiveFD); and (c) propulsive peak force of nondominant upper limb (PropulsiveFND). Significant differences were found in the rate of force production (RateFD) between the majority cadences in both exercises. The RateFD reached ~68% of the force in dry-land conditions, and lower cadences promoted a higher rate of force variation (ΔForce). Most actions were asymmetric, except for the HA at 135 b·min–1. In conclusion, the musical cadence of 135 b·min–1 seems to elicit a desired rate of force production with a symmetric motion in both exercises.

Nonlinear Periodic Oscillations of Micro-Voids in a Class of Incompressible Hyper-Elastic Spheres

2011 ◽  
Vol 52-54 ◽  
pp. 220-225
Author(s):  
Miao Miao Cai ◽  
Jia Na Meng ◽  
Xue Gang Yuan ◽  
Da Tian Niu
Keyword(s):  
Differential Equation ◽  
Oscillation Amplitude ◽  
Tensile Load ◽  
Periodic Oscillation ◽  
Transversely Isotropic ◽  
Material Model ◽  
Symmetric Motion ◽  
Order Ordinary Differential Equation ◽  
Periodic Oscillations ◽  
Hyper Elastic

The problem of radially symmetric motion is examined for a pre-existing micro-void in the interior of a sphere under a suddenly applied outer surface tensile load, where the sphere is composed of a homogeneous incompressible hyper-elastic material. Through qualitatively analyzing the second-order ordinary differential equation that describes the motion of the pre-existing micro-void with time, some interesting conclusions are proposed. For any given values of surface tensile loads, it is proved that the motion of the pre-existing micro-void with time presents a nonlinear periodic oscillation, however, in certain cases, the oscillation amplitude increases discontinuously with the increasing values of surface tensile loads. Finally, based on the known transversely isotropic incompressible Gent-Thomas material model as an example, numerical simulations are carried out.

Period-3 Motions in a Parametrically Exited Inverted Pendulum

2020 ◽  
Author(s):  
Albert C. J. Luo ◽  
Chuan Guo
Keyword(s):  
Numerical Simulations ◽  
Inverted Pendulum ◽  
Period Doubling ◽  
Mapping Method ◽  
Eigenvalue Analysis ◽  
Symmetric Motion ◽  
Bifurcation Tree ◽  
Implicit Mapping ◽  
Stability And Bifurcation ◽  
Period Doubling Bifurcations

Abstract In this paper, period-3 motions in a parametrically exited inverted pendulum are analytically investigated through a discrete implicit mapping method. The corresponding stability and bifurcation conditions of the period-3 motions are predicted through eigenvalue analysis. The symmetric and asymmetric period-3 motions are obtained on the bifurcation tree, and the period-doubling bifurcations of the asymmetric period-3 motions are observed. The saddle-node and Neimark bifurcations for symmetric period-3 motions are obtained. The saddle-bifurcations of the symmetric period-3 motions are for symmetric motion appearance (or vanishing) and onsets of asymmetric period-3 motion. Numerical simulations of the period-3 motions in the inverted pendulum are completed from analytical predictions for illustration of motion complexity and characteristics.

Dynamic Vibrations and Stresses in Elastic Cylinders and Spheres

1966 ◽  
Vol 33 (4) ◽  
pp. 825-830 ◽  
Author(s):  
G. Cinelli
Keyword(s):  
Circular Cylindrical Shell ◽  
Hankel Transform ◽  
Dynamic Loads ◽  
Torsional Motion ◽  
Spherical Shells ◽  
Symmetric Motion ◽  
Line Load ◽  
Elastic Cylinders ◽  
Finite Hankel Transform ◽  
Cylinders And Spheres

A new finite Hankel transform [1] is used to find the transient displacement and stresses in thick elastic cylinders and spheres when the surfaces are subjected to dynamic loads for the following problems: (a) Pure radial and torsional motion of an infinitely long circular cylindrical shell; (b) radially symmetric motion of a spherical shell. The loads applied to both surfaces of the cylindrical and spherical shells are completely arbitrary functions of space (for the torsional case) and time. Employing the solutions obtained for the arbitrary loads, the spatial and temporal positions of these loads are then specialized to standard forms, such as a line load, band load, impulse, and so on, and the corresponding motion and stresses are found.

Study of the axially symmetric motion of an incompressible viscous fluid between two concentric rotating spheres

1990 ◽  
Vol 24 (1) ◽  
pp. 1-23 ◽  
Author(s):  
J. C. Gagliardi ◽  
N. J. Nigro ◽  
A. F. Elkouh ◽  
J. -K. Yang ◽  
L. Rodriguez
Keyword(s):  
Viscous Fluid ◽  
Incompressible Viscous Fluid ◽  
Axially Symmetric ◽  
Symmetric Motion

Rational Bézier Line-Symmetric Motions

1999 ◽  
Author(s):  
Shutian Li ◽  
Q. J. Ge
Keyword(s):  
Ruled Surface ◽  
Geometric Design ◽  
Ruled Surfaces ◽  
Line Geometry ◽  
Symmetric Motion ◽  
Computer Aided Geometric Design ◽  
De Casteljau Algorithm ◽  
Computer Aided ◽  
Kinematic Geometry

Abstract This paper brings together line geometry, kinematic geometry of line-symmetric motions, and computer aided geometric design to develop a method for geometric design of rational Bézier line-symmetric motions. By taking advantage of the kinematic geometry of a line-symmetric motion, the problem of synthesizing a rational Bézier line-symmetric motion is reduced to that of designing a rational Bézier ruled surface. In this way, a recently developed de Casteljau algorithm for line-geometric design of ruled surfaces can be applied. An example is presented in which the Bennet motion is represented as a rational Bézier line-symmetric motion whose basic surface is a hyperboloid.

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