scholarly journals Gripping during climbing of arboreal snakes may be safe but not economical

2014 ◽  
Vol 10 (8) ◽  
pp. 20140434 ◽  
Author(s):  
Greg Byrnes ◽  
Bruce C. Jayne
Keyword(s):  
Body Weight ◽  
Safety Factor ◽  
Normal Force ◽  
Force Production ◽  
Vertical Cylinder ◽  
Muscular Force ◽  
Arboreal Snakes

On the steep surfaces that are common in arboreal environments, many types of animals without claws or adhesive structures must use muscular force to generate sufficient normal force to prevent slipping and climb successfully. Unlike many limbed arboreal animals that have discrete gripping regions on the feet, the elongate bodies of snakes allow for considerable modulation of both the size and orientation of the gripping region. We quantified the gripping forces of snakes climbing a vertical cylinder to determine the extent to which their force production favoured economy or safety. Our sample included four boid species and one colubrid. Nearly all of the gripping forces that we observed for each snake exceeded our estimate of the minimum required, and snakes commonly produced more than three times the normal force required to support their body weight. This suggests that a large safety factor to avoid slipping and falling is more important than locomotor economy.

Effect of the speed of taekwondo kick execution on the muscular force production, obtained by biomechanical modeling

2019 ◽  
Vol 3 (5) ◽  
pp. 42-49
Author(s):  
Pedro Vieira Sarmet Moreira ◽  
◽  
Kristy Alejandra Godoy Jaimes ◽  
Luciano Luporini Menegaldo ◽  
◽  
...  
Keyword(s):  
Force Production ◽  
Biomechanical Modeling ◽  
Muscular Force

Deformable Blade Element and Unsteady Vortex Lattice Fluid-Structure Interaction Modeling of a 2D Flapping Wing

2020 ◽  
Author(s):  
Joseph Reade ◽  
Mark A. Jankauski
Keyword(s):  
Vortex Lattice ◽  
Normal Force ◽  
Aerodynamic Force ◽  
Fluid Structure Interaction ◽  
Force Production ◽  
Flapping Wing ◽  
Energetic Efficiency ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Blade Element

Abstract Flapping insect wings experience appreciable deformation due to aerodynamic and inertial forces. This deformation is believed to benefit the insect’s aerodynamic force production as well as energetic efficiency. However, the fluid-structure interaction (FSI) models used to estimate wing deformations are often computationally demanding and are therefore challenged by parametric studies. Here, we develop a simple FSI model of a flapping wing idealized as a two-dimensional pitching-plunging airfoil. Using the Lagrangian formulation, we derive the reduced-order structural framework governing wing’s elastic deformation. We consider two fluid models: quasi-steady Deformable Blade Element Theory (DBET) and Unsteady Vortex Lattice Method (UVLM). DBET is computationally economical but does not provide insight into the flow structure surrounding the wing, whereas UVLM approximates flows but requires more time to solve. For simple flapping kinematics, DBET and UVLM produce similar estimates of the aerodynamic force normal to the surface of a rigid wing. More importantly, when the wing is permitted to deform, DBET and UVLM agree well in predicting wingtip deflection and aerodynamic normal force. The most notable difference between the model predictions is a roughly 20° phase difference in normal force. DBET estimates wing deformation and force production approximately 15 times faster than UVLM for the parameters considered, and both models solve in under a minute when considering 15 flapping periods. Moving forward, we will benchmark both low-order models with respect to high fidelity computational fluid dynamics coupled to finite element analysis, and assess the agreement between DBET and UVLM over a broader range of flapping kinematics.

ABOUT SAFETY FACTOR LOAD FOR SOIL DW IN GEOTECHNICS

2016 ◽  
Vol 4 (3) ◽  
pp. 0-0
Author(s):  
Алексей Радкевич ◽  
Aleksey Radkevich ◽  
Александр Митькин ◽  
Aleksandr Mitkin ◽  
Б Кулачкин ◽  
...  
Keyword(s):  
Body Weight ◽  
Safety Factor ◽  
Safety Factors ◽  
Main Criterion ◽  
Reliability Coefficients

Reliability coefficients on loading from a body weight of metal, concrete and soil are considered. The analysis of the evolution of safety factors for load from its own weight. Noted that the safety factor of load from the weight of the soil is the main criterion of reliability and safety in Geotechnics and construction in General. Admitted blunder in SP 20.13330.2011. Heterogeneity of soil character bedding are the main characteristics that fully characterize the company according to the static sounding. The reliability coefficients for the load of its own weight soils significantly underestimated and may not be practically identical with concrete. It is recommended that you increase the value of the coefficient of reliability of load from the weight of the soil, and correct the terminology.

scholarly journals A Study on Somatotype Profiles of the Players in Turkish Bocce National Team

2018 ◽  
Vol 6 (2) ◽  
pp. 28
Author(s):  
Nebahat Eler ◽  
Serdar Eler
Keyword(s):  
Body Weight ◽  
Body Fat ◽  
Body Fat Percentage ◽  
Muscular Force ◽  
Fat Percentage ◽  
Tennis Players ◽  
National Team ◽  
Significant Difference ◽  
Package Program ◽  
The Mean

The aim of this study is to determine the differences between the somatotype profiles and inter-disciplinary somatotype profiles of the Turkish Bocce National Team players. In this study, the mean age of the Turkish Men’s Bocce National Team (n-32) was determined as 21,75±2,35 (years), mean height was 177,62±1,03 (cm), mean body weight was 70,75±0,70 (kg), mean Body Mass Index (BMI) was 22,31±1,06 kg/m2, mean body fat percentage was 16,05±1%. The mean age of the Turkish Women’s Bocce National Team (n-21) was 21,76±2,12 (years), mean height was 165,33±4,24 (cm), mean body weight 55,14±6,36 (kg), mean BMI was 23,22±1,06 kg/m2 mean body fat percentage was 16,05±1%. The Heath-Carter method was used in determining the somatotype profiles of the players. the The statistical analyses in the study were made by using the SPSS 20.0 package program. Somatotype profile in men was determined endomorphic 3,21±0,33; mesomorph 5,04±1,11; ectomorphic 2,20±0,18 as mesomorphic-endomorphic; in women, endomorphic 3,33±1,42; mesomorph 5,08±0,26; ectomorphic 2,07±0,09 as mesomorphic-endomorphic. In this study, the somatotype profiles of the Turkish Bocce National Team players were determined, and a statistically significant difference was detected between the volo and petanque-raffa disciplines in men and women (p<0,05). It is believed that this difference stems from the physical performance requiring more muscular force in volo discipline than the petanque and raffa disciplines. In this study, the somatotype components are similar in tennis players in volo men group and the archers, judo players and Water polo players of the other groups (Men-women petanque and raffa group, Women volo group).

Ontogenetic scaling of burrowing forces in the earthworm Lumbricus terrestris

2000 ◽  
Vol 203 (18) ◽  
pp. 2757-2770 ◽  
Author(s):  
K.J. Quillin
Keyword(s):  
Body Weight ◽  
Body Mass ◽  
Force Production ◽  
Lumbricus Terrestris ◽  
Axial Forces ◽  
Order Of Magnitude ◽  
Ontogenetic Effects ◽  
Radial Forces ◽  
The Difference ◽  
Earthworm Lumbricus

In hydrostatic skeletons, it is the internal fluid under pressure surrounded by a body wall in tension (rather than a rigid lever) that enables the stiffening of the organism, the antagonism of muscles and the transmission of force from the muscles to the environment. This study examined the ontogenetic effects of body size on force production by an organism supported with a hydrostatic skeleton. The earthworm Lumbricus terrestris burrows by forcefully enlarging crevices in the soil. I built a force-measuring apparatus that measured the radial forces as earthworms of different sizes crawled through and enlarged pre-formed soil burrows. I also built an apparatus that measured the radial and axial forces as earthworms of different sizes attempted to elongate a dead-end burrow. Earthworms ranging in body mass m(b) from hatchlings (0.012 g) to adults (8.9 g) exerted maximum forces (F, in N) during active radial expansion of their burrows (F=0.32 m(b)(0.43)) and comparable forces during axial elongation of the burrow (F=0.26 m(b)(0.47)). Both these forces were almost an order of magnitude greater than the radial anchoring forces during normal peristalsis within burrows (F=0.04 m(b)(0.45)). All radial and axial forces scaled as body mass raised to the 2/5 power rather than to the 2/3 power expected by geometric similarity, indicating that large worms exert greater forces than small worms on an absolute scale, but the difference was less than predicted by scaling considerations. When forces were normalized by body weight, hatchlings could push 500 times their own body weight, while large adults could push only 10 times their own body weight.

scholarly journals Gecko Inspired Suit Could Have you Climbing the Wall

2008 ◽  
Vol 58 ◽  
pp. 66-71
Author(s):  
Nicola Maria Pugno
Keyword(s):  
Body Weight ◽  
Adhesion Strength ◽  
Safety Factor ◽  
Adhesion Force ◽  
Scaling Up ◽  
The Body ◽  
Dust Particles ◽  
Biomimetic Materials

Theoretical van der Walls gloves could generate an adhesion force comparable to the body weight of ∼500 men. Even if such a strength remains practically unrealistic (and undesired, in order to achieve an easy detachment), due to the presence of contact defects, e.g. roughness and dust particles, its huge value suggests the feasibility of Spiderman gloves. The scaling-up procedure, from a spider to a man, is expected to decrease the safety factor (body weight over adhesion force) and adhesion strength, that however could remain sufficient for supporting a man. Scientists are developing fascinating new biomimetic materials, e.g. gecko-inspired. Here we complementary face the problem of the structure rather than of the material, designing and fabricating a first prototype of Spiderman gloves, capable of supporting ∼10 kilograms each, thanks to new Adhesive Optimization Laws.

Muscular force production after concentric contraction

2008 ◽  
Vol 41 (11) ◽  
pp. 2422-2429 ◽  
Author(s):  
Natalia Kosterina ◽  
Håkan Westerblad ◽  
Jan Lännergren ◽  
Anders Eriksson
Keyword(s):  
Force Production ◽  
Muscular Force ◽  
Concentric Contraction

???Psyching-Up??? and Muscular Force Production

2003 ◽  
Vol 33 (1) ◽  
pp. 47-58 ◽  
Author(s):  
David Tod ◽  
Fiona Iredale ◽  
Nicholas Gill
Keyword(s):  
Force Production ◽  
Muscular Force

scholarly journals The evolution of two distinct strategies of moth flight

2021 ◽  
Vol 18 (185) ◽  
Author(s):  
Brett R. Aiello ◽  
Usama Bin Sikandar ◽  
Hajime Minoguchi ◽  
Burhanuddin Bhinderwala ◽  
Chris A. Hamilton ◽  
...  
Keyword(s):  
Body Weight ◽  
Three Dimensional ◽  
Force Production ◽  
High Amplitude ◽  
Wing Shape ◽  
Wing Morphology ◽  
Aerodynamic Modelling ◽  
Similar Body ◽  
Support Body Weight ◽  
Force Profiles

Across insects, wing shape and size have undergone dramatic divergence even in closely related sister groups. However, we do not know how morphology changes in tandem with kinematics to support body weight within available power and how the specific force production patterns are linked to differences in behaviour. Hawkmoths and wild silkmoths are diverse sister families with divergent wing morphology. Using three-dimensional kinematics and quasi-steady aerodynamic modelling, we compare the aerodynamics and the contributions of wing shape, size and kinematics in 10 moth species. We find that wing movement also diverges between the clades and underlies two distinct strategies for flight. Hawkmoths use wing kinematics, especially high frequencies, to enhance force and wing morphologies that reduce power. Silkmoths use wing morphology to enhance force, and slow, high-amplitude wingstrokes to reduce power. Both strategies converge on similar aerodynamic power and can support similar body weight ranges. However, inter-clade within-wingstroke force profiles are quite different and linked to the hovering flight of hawkmoths and the bobbing flight of silkmoths. These two moth groups fly more like other, distantly related insects than they do each other, demonstrating the diversity of flapping flight evolution and a rich bioinspired design space for robotic flappers.

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