scholarly journals Preliminary Study on Psychomotor Abilities Decisive for Technical Routines in Rhythmic Gymnastics

2020 ◽  
Vol 11 (4Sup1) ◽  
pp. 62-80
Author(s):  
Ștefania Chiriac ◽  
◽  
Silvia Teodorescu ◽  
Aura Bota ◽  
◽  
...  
Keyword(s):  
Previous Analysis ◽  
Technical Skills ◽  
Travel Speed ◽  
Dynamic Tests ◽  
Rhythmic Gymnastics ◽  
Preparatory Stage ◽  
Preliminary Study ◽  
Static And Dynamic Tests ◽  
Key Features ◽  
Rhythmic Gymnasts

The aim of the research is to establish the level of some psychomotor abilities by determining the rhythmic gymnasts’ capability to perform apparatus-specific technical skills within the composition of their routines, according to the provisions of the 2017-2020 Code of Points. The Wireless training timer (Witty) testing equipment was used to assess relevant types of speed in junior rhythmic gymnasts. The reaction time, execution time and travel speed time were measured in similar technical conditions or close to those encountered in training and competitions. The 14 gymnasts included in the research, aged between 13 and 15 years, are part of the National Olympic Centre for juniors in Arad, all being enrolled in the preparatory stage of training. The analysis of the data from both static and dynamic tests established a referential for the forms of speed to be enhanced by means of apparatus-specific technical routines. Results provide interesting information on the average values, inter-individual differences and homogeneity-related issues (which are relevant especially for gymnasts performing in the group event). The key features of these data, as well as previous analysis of junior routines for the 2017-2020 Olympic cycle, have led us to the conclusion that, in order to get a high score for apparatus difficulty/mastery, more difficulty elements should be added, which requires an increase in all kinds of speed involved by the technique of a specific event.

The effect of the indenter elasticity on the Hertzian fracture of brittle materials

1973 ◽  
Vol 334 (1596) ◽  
pp. 95-117 ◽  
Keyword(s):  
Fracture Stress ◽  
Opposite Effect ◽  
Test Material ◽  
Test Surface ◽  
Dynamic Tests ◽  
Frictional Forces ◽  
Consistent Increase ◽  
Static And Dynamic Tests ◽  
Ring Crack ◽  
Ring Cracks

A spherical indenter loaded statically or dynamically into contact with the surface of a brittle material produces a well-defined ring crack. This phenomenon, when interpreted by the Hertz theory of elastic contact, provides a convenient test for the strength of the material. If the elastic modulus of the indenter is different from that of the test material, e. g. a steel indenter in contact with a glass surface, frictional forces are brought into play at the interface which modify the Hertz distribution of contact stress. This effect has been examined both theo­retically and experimentally. An indenter which is more rigid than the test surface is shown to lead to an apparent increase in fracture strength of the material, a less rigid indenter has the opposite effect. Static and dynamic tests of plate glass showed a consistent increase in apparent fracture stress of about 50 % using spherical steel indenters compared with glass indenters. This increase agrees well with the influence of friction upon the Hertzian stress calculated theoretically. The average radius of the ring cracks produced by steel indenters was observed to be greater than that produced by glass indenters, an effect of friction also predicted by the theory. Secondary ring cracks of smaller radius have frequently been observed during unloading of a steel indenter. These were not found when a glass indenter was used and an explanation is suggested in terms of the frictional effect which arises from a difference in elasticity between the indenter and the test surface.

Evaluation Method of U-Bolt Energy Absorption

2009 ◽  
Author(s):  
Eiji Shirai ◽  
Tetsuya Zaitsu ◽  
Kazutoyo Ikeda ◽  
Toshiaki Yoshii ◽  
Masami Kondo ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Evaluation Method ◽  
Design Procedure ◽  
Piping System ◽  
Design Technique ◽  
Dynamic Tests ◽  
Key Issues ◽  
Static And Dynamic Tests ◽  
Force Displacement ◽  
Rigid Design

At domestic PWR plants in Japan, one of the major key issues is earthquake-proof safety [1–3]. Recently, a design procedure using energy absorption, not conventional rigid design, was authorized according to revised review guidelines for aseismic design (JEAC4601). Therefore, we focused on the design technique that utilizes energy absorption effects to reduce the seismic responses of the piping system with U-Bolt, by the static and dynamic tests of simplified piping model supported by U-Bolt. The force-displacement characteristics and a fatigue diagram were obtained by the tests.

Inspection and Model Experiment of a Damaged Arch Bridge

2007 ◽  
Vol 340-341 ◽  
pp. 223-228
Author(s):  
Ying Fang Fan ◽  
Zhi Qiang Hu ◽  
Jing Zhou
Keyword(s):  
Model Experiment ◽  
Dynamic Test ◽  
Dynamic Responses ◽  
Dynamic Tests ◽  
Arch Bridge ◽  
Mechanical Responses ◽  
Organic Glasses ◽  
Bridge Model ◽  
Static And Dynamic Tests ◽  
Good Agreement

The structural behavior of an old six-span reinforced concrete arch bridge, which has been in service for about 40 years, is investigated. Field monitoring (inclusive of test of material property, static and dynamic test of the bridge) was conducted, static and dynamic responses of the bridge are obtained. Based on the primitive bridge, a scaled one-span bridge model was fabricated by organic-glasses. Both the static and dynamic tests were executed on the bridge model in the laboratory. Since the arch rib is the crucial member for the arch bridge, 7 notches were cut on both arch ribs of the bridge model to simulate different damages of the arch rib. Mechanical responses of the bridge with different damages on the arch ribs were achieved. FEM analyses were preformed on the bridge as well. Numerical results show good agreement with the experimental results.

Load capacity assessment of “Antonio Dovali Jaime” bridge using static and dynamic tests

2008 ◽  
pp. 85-85
Author(s):  
V Robles ◽  
M Ruiz-Sandoval ◽  
J Téllez ◽  
F Burgos ◽  
O Ortiz ◽  
...  
Keyword(s):  
Load Capacity ◽  
Capacity Assessment ◽  
Dynamic Tests ◽  
Static And Dynamic Tests

scholarly journals Závislost hypermobility na výskytu lehkých mozečkových dysfunkcí u závodnic v moderní gymnastice

2016 ◽  
Vol 10 (1) ◽  
pp. 96-102
Author(s):  
Kateřina Kapounková ◽  
Ivan Struhár ◽  
Jitka Kopřivová
Keyword(s):  
Czech Republic ◽  
General Population ◽  
Hip Joint ◽  
Brain Dysfunction ◽  
The Czech Republic ◽  
The People ◽  
Rhythmic Gymnastics ◽  
Joint Range ◽  
Rhythmic Gymnasts ◽  
Movement Test

The aim of the study was to ascertain information upon the occurrence of hypermobility as well as the symptoms of light brain dysfunction in rhythmic gymnasts and to prove their relationship. The research sample consisted of 78 girls from rhythmic gymnastics teams from the Czech Republic with average age 12,81 ± 2,47. The study used deliberate selection on the basis of chosen criteria: women, age 10 – 18 years, at least 5 let of specialised training in rhythmic gymnastics, week load at least 10 hours. The diagnostics of hypermobility used the method of measuring joint range with the aid of goniometer. The range of the movement of hip joint was measured and Janda test. The diagnostics of mild brain dysfunction diagnostics used orientation brain tests. It is the test of tax, which is aimed upon the proper aiming of movement, test of diadochokinesis, which is aimed at the ability to perform alternating movements, and the test of stability using Romberg pose on a balance platform with open eyes. The results of the goniometric measurement showed a significant flexibility of the gymnasts, mainly in the area of their hip joint (flexe right hip joint 161,09 °; ± 14,78 and flexe left hip joint 158,54 ° ± 14,05). When diagnosing mild brain dysfunction using tax, in both the upper and the lower extremities, no pathology was ascertained, on the contrary, however dysdiadochokinesis was found in 7 gymnasts. The results of the Romberg pose on the balance platform were mildly above the norm (compared with general population), nonetheless, the 7 people with dysdiadochokinesis showed results under the values of the general population. The people with dysdiadochokinesis, also showed worse results in the Romberg pose on the balance platform, as well as the symptoms of hypermobility, which where proved by goniometric examination.

Measurement of the Elastic Moduli of Structural Adhesives by a Resonant Bar Technique

1976 ◽  
Vol 18 (3) ◽  
pp. 149-158 ◽  
Author(s):  
R. D. Adams ◽  
J. Coppendale
Keyword(s):  
Thin Film ◽  
Elastic Moduli ◽  
Dynamic Tests ◽  
Structural Adhesives ◽  
Young’S Moduli ◽  
Epoxy Adhesives ◽  
Dynamic Torsion ◽  
Static And Dynamic Tests

A method of measuring the dynamic torsion and Young's moduli of a thin film of adhesive is described. The accuracy of the technique and its suitability for structural adhesives is discussed. Values of modulus obtained using this method are compared with values obtained from static and dynamic tests on bulk specimens of three epoxy adhesives.

Wake measurements of oscillating supercritical airfoil in compressible flow

2019 ◽  
Vol 43 (1) ◽  
pp. 112-121
Author(s):  
Behnaz Beheshti Boroumand ◽  
Mahmoud Mani
Keyword(s):  
Mach Number ◽  
Angle Of Attack ◽  
Time History ◽  
Mean Value ◽  
Hot Wire ◽  
Dynamic Tests ◽  
Flow Parameters ◽  
Free Stream Mach Number ◽  
Static And Dynamic Tests ◽  
Wake Characteristics

Boundary layer and wake behaviors are strongly affected by airfoil motion. Moreover, parameters like body oscillation frequency, oscillation type, Mach number, and angle of attack play main roles in wake characteristics. In this research, both static and dynamic tests were carried out in a tri-sonic wind tunnel to study wake profiles experimentally by hot wire anemometry. All data were recorded at a free stream Mach number of 0.4. Quarter-length and half-length of chord were also considered as downstream distances from the trailing edge in pitching motions of mean angle of attack of −0.4°. Frequencies of 3 Hz and 6 Hz with amplitude of 3° were chosen as oscillation parameters. Voltages at hot wire outputs were measured and analyzed qualitatively and statistically with root-mean-square, correlation, mean value distribution, time history, and frequency. Flow parameters were obtained by computational studies under similar experimental test conditions. The wake characteristics obtained from numerical and experimental methods were compared.

To the Question of an Experimental Assessment of the Fatigue Characteristics of a Transversal Metal-Composite Compound

2020 ◽  
Vol 299 ◽  
pp. 241-245
Author(s):  
Mikhail V. Astahov ◽  
Irina I. Sorokina ◽  
Ekaterina V. Slavkina
Keyword(s):  
Test Bench ◽  
Normal Force ◽  
Fatigue Curve ◽  
Polymer Composite Material ◽  
The Body ◽  
Metal Composite ◽  
Dynamic Tests ◽  
Experimental Assessment ◽  
Fatigue Characteristics ◽  
Static And Dynamic Tests

The possibilities of using composite materials for the modernization and repair of structures are considered. Based on a review of the sources of literature, it was concluded that the use of glue-pin combined connections is promising. For a combined transversal connection with one fastener, static and dynamic tests were performed on an Instron 1121 test bench. The loading was carried out with a normal force, pulling the fastener out the body of a polymer composite material. The analysis of experimental data is carried out, the fatigue curve is constructed.

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