Maximum Radial Displacement Research Articles

Analytical and numerical solutions to the problem of the influence of pipes for receipt and distribution on the stress-strain state of the tank wall

The article considers the problem of determining the stress-strain state of the tank wall in the area where it connects with receiving and dispensing pipes (PRP). One of the significant factors influencing the overall stress-strain state of the tank wall, which is a thin shell according to fundamental laws of structural mechanics, is the presence or absence of settlement of the bases and foundations of the structural elements of the tank.The article uses both classical structural mechanics methods, and existing analytical solutions. In addition to applying numerical methods, particularly the finite element method (FEM), implemented through the ANSYS software package The developed numerical model of the RVSP-20000 tank using the finite element method in ANSYS PC allowed to determine the displacements, deformations, and stresses in the structures in the junction area of the receiving and dispensing pipe and the RVSP tank wall. The numerical calculations revealed. As the numerical calculation in this article using the FEM complex has shown, the PRP, which has a connection with the reservoir at the level of maximum radial displacements of the wall from the hydrostatic pressure of the stored liquid, creates a significantly altered and potentially hazardous stress-strain state in the contact zone. This highlights the necessity of monitoring potential incompatible deformations in the foundations of both the PRP and the reservoir itself, and, if needed, implementing appropriate engineering measures.

Numerical Simulation of Backfilling Construction for Underground Reinforced Concrete Grain Silos

Food security is an important guarantee for national security and public health. Underground reinforced concrete (RC) grain silos can provide a quasi-low temperature environment for grain storage, effectively ensuring the quality of the stored grain. The stress status of the underground silo during soil backfilling construction is complex, which puts the structure at risk of failure. The present study developed a numerical simulation method to investigate the mechanical properties of underground silos during backfilling construction processes. A finite element (FE) analysis of the backfilling construction process of an underground RC grain silo was conducted, and the nonlinear contact between the underground silo and the surrounding soil, as well as the material nonlinear behavior of the soil, was considered. The deformation characteristics and stress distribution of the underground silo during the backfilling construction process were revealed. The results indicate that the underground RC grain silo exhibits good mechanical performance. The underground silo underwent overall settlement during the backfilling construction process, with a total settlement of 21 mm. The maximum radial displacement of the silo wall and the maximum deflection of the radial primary beam were 0.84 mm and 5.67 mm, respectively, both of which were smaller than the limit values. After the completion of backfilling construction, there was a high risk of concrete cracking of the silo wall. The maximum radial and circumferential tensile stresses of the concrete at the silo top were both high, which led to cracking in the top of the silo. Our research results provide important support for the design and evaluation of underground RC grain silos.

Deformation and Stress Prediction of Tank under Uneven Settlement

Abstract The differential settlement of crude oil tank foundations can lead to deformation and stress concentration, posing significant risks to the safe operation of storage tanks. This study developed a finite element model for a large crude oil storage tank subjected to harmonic settlement to address the issue of non-uniform settlement around the tank. The model systematically varied the tank’s diameter-to-thickness ratio, height-to-diameter ratio, and the wind beam’s relative bending stiffness. The research examined the impact of these three factors on the maximum dimensionless radial displacement at the tank top and the maximum equivalent stress at the tank bottom. A predictive method was proposed for estimating the radial displacement at the tank top and the equivalent stress at the tank bottom under uneven settlement, offering valuable insights for assessing the integrity of large tanks in such conditions.

HaptiYarn: Development of an Actuator Yarn That Can Transform Everyday Textiles Into Haptic Devices.

A method of providing localised haptic feedback at precise locations on the body, utilising a lightweight textile garment is presented in this short paper. The textile comprises of subtly integrated actuator yarns (HaptiYarns) which are controlled by electropneumatic circuitry. Each yarn has two functional layers, an inner porous textile layer with limited extensibility and a second, durable outer layer made from an extensible elastomer. The HaptiYarns can provide radial forces and a maximum radial displacement of 28.09 ± 0.14 mm. It was found that the intrinsic addition of graphite powder (5% by weight), during elastomer preparation, offered better resistance to layer delamination and increased the ability of the yarn to withstand higher internal air pressures by 48%. Both the graphite-filled composite and the graphite free yarns demonstrated high durability, withstanding cyclic testing of >7500 cycles while having no significant impact on the force feedback. Finally, a wearable prototype knitted textile garment is presented with eight HaptiYarns subtly integrated within it and connected to a virtual reality (VR) program providing an immersive haptic experience. These yarns offer the potential to transform everyday clothing into wearable haptic devices with potential to revolutionise healthcare, VR-based training, gaming, and entertainment sectors.

Advanced Analysis of Structural Performance in Novel Steel-Plate Concrete Containment Structures

This paper investigates the structural performance of novel steel-plate concrete containment structures, focusing on third-generation nuclear power plants. To address the challenges of increased complexities and costs associated with double-layer containment designs, this study explores the potential of steel-plate concrete structures to enhance safety, economic efficiency, and construction simplicity. The steel-plate concrete structure, characterized by its core concrete and dual steel plates, shows superior compressive strength, bending resistance, and elastoplasticity. Extensive numerical analyses, including finite element modeling and thermal-stress coupling, were conducted under various load conditions. Under structural integrity test conditions, the maximum radial displacement observed was 24.59 mm. Under design basis conditions, the maximum radial displacement was 47.61 mm; under severe accident conditions, it was 53.83 mm. The ultimate bearing capacity was 0.91 MPa, 2.17 times the design pressure. This study concludes that the steel-plate concrete containment structure maintains a high safety margin under all tested conditions, with stress and strain well within acceptable limits. It can effectively serve as a robust barrier against radioactive leakage and malicious impacts, providing a viable alternative to conventional containment designs.

Shock Response of Water-Protected Spherical Explosion Containment Vessels

Abstract Explosion containment vessels (ECVs) are important equipment used for underwater explosion experiment research. In this paper, a method is proposed to improve the blast resistance of the ECV by placing it in the water medium. The shock response caused by the underwater explosion in a spherical ECV is studied. The single-layer thin-walled spherical vessel shell submerged in an infinite domain water medium is deduced and simplified as a single-degree-of-freedom elastic vibration system with viscous damping. The underwater explosion shock wave is simplified to an exponential shock loading, and the analytical solutions of the radial shock vibration of the spherical shell are obtained using Duhamel's integrals. Compared with the numerical simulation results, the accuracy of the theoretical model is verified. The study results show that the water medium radiates out vibration energy and plays an important role in eliminating vibration through damping. It is found that the vibration damping ratio can be controlled by adjusting the vessel radius and thickness, so that the vibration of the shell can be controlled within three periods and the impact fatigue can be reduced. In addition, the radiation damping of the water medium greatly reduces the maximum radial displacement of the spherical shell, which significantly improves the blast resistance of the spherical shell.

Interaction of ultrasonically driven bubble with a soft tissue-like boundary

This study investigates the size-dependent dynamics of bubbles and their interaction with soft boundaries under various ultrasound (US) conditions. We found that bubble behavior is influenced by size, with smaller bubbles displaying reduced inertial motion in similar ultrasound environments. Detailed analyses of three bubble sizes (1.5 µm, 15 µm, and 150 µm) next to a soft 1 kPa boundary revealed distinct patterns in radial oscillation, bubble center displacement, and boundary deflection for different ultrasound frequencies (5 kHz − 4 MHz). The smallest bubble maintained a spherical shape, while the largest experienced significant shape changes, indicative of impending jet formation. Investigating interactions at various frequencies highlighted the collapse tendency of the larger bubbles, showcasing maximum radial amplitude, displacement, and bubble wall velocity around its natural frequency. The presence of a soft boundary minimally affected radial amplitude and velocity, while the bubble displacement was contingent on the soft boundary modulus. Furthermore, boundary responses demonstrated that softer boundaries experienced less stress during bubble oscillations, exhibiting sharper peaks at resonance frequencies for larger bubbles. These findings provide valuable insights into optimizing ultrasound conditions for a variety of applications, highlighting the influence of bubble size and boundary properties on outcomes.

Biomechanical Analysis of Orbital Development: A Finite Element Analysis by an Experimentally Validated Model.

Constructing orbital finite element models capable of simulating the development process and analyzing the biomechanical mechanism. Four normal orbits from 1-month-old New Zealand white rabbits were used in this study. Toshiba Aquilion Prime was used to determine the computed tomography scan and direct orbital pressure manometry using an improved manometer based on the TSD104 pressure sensor transducer. The finite element analysis was conducted using the ANSYS Workbench platform. The biomechanics of each orbital wall improved to varying degrees as the rabbit orbit grew and developed. The von Mises stress in both rabbits initially concentrated at the lower edge of the posterior orbital wall, expanded to the entire orbit, and ultimately became more significant in the biomechanics of the region that consisted of the posterior orbital and superior orbital walls. During the expansion phase, the biomechanics of both rabbits gradually developed from the nasal side to the occipital side for radial displacement. It is evident that the finite element model is a good fit for simulating the physiological development of the rabbit orbit. The maximum radial displacement and maximum von Mises stress appeared 2 intermissions during the development of the orbit, at about 50 to 60 days and 80 to 90 days. This study establishes a theoretical foundation for the creation of a biomechanical model of human orbital development by offering the first finite element model to simulate orbital development and analyze the biomechanical mechanism of orbital pressure on orbital development.

Identification of Peripheral Fatigue through Exercise-Induced Changes in Muscle Contractility.

The aim of this study was to assess whether tensiomyography is a tool sensitive enough to detect peripheral fatigue. Twenty-six strength-trained men were split into two groups: 1) a fatigued group (FG), who performed a full-squat (SQ) standardized warm-up plus 3 x 8 SQs with 75% 1RM with a 5-min rest interval, and 2) a non-fatigued group (NFG), who only did the SQ standardized warm-up. The countermovement jump (CMJ), maximal isometric force (MIF) in the SQ at 90º knee flexion, and TMG in vastus medialis (VM) and vastus lateralis (VL) muscles were assessed pre- and post-protocols. Data were analyzed through mixed ANOVA, logistic regression analysis, and receiver-operating curves. There were significant group x time interactions (p < 0.01) for CMJ height, MIF, maximal radial displacement (Dm), and radial displacement velocity (Vrd90) since the FG acutely decreased in these variables, while no significant changes were observed for the NFG. The logistic regression showed a significant model for detecting fatigue, whether it used the CMJ or MIF, with only the relative change in VL-Vrd90 as a fatigue predictor. The determination of the area under the curve showed that Dm and Vrd90 had good to excellent discriminative ability. Dm and Vrd90 are sensitive to detect fatigue in VL and VM muscles in resistance training contexts.

STUDY OF THE WALL RIGIDITY OF A VERTICAL CYLINDRICAL STEEL TANK DURING ITS INSTALLATION BY THE SPIRAL-WOUND METHOD

The paper presents the results of a study of the influence of the wall diameter of a vertical cylindrical steel tank designed for storing petroleum products on its stiffness characteristics and the applicability (for the manu-facture of this wall) of the spiral-winding metod, according to which the tank wall is made of rolled sheet metal, during the unwinding of which a wall is formed in the form of a spiral, ad-jacent turns of which are continuously connected by a welded seam, forming a sealed shell.To solve the problem, a finite element analysis of the tank wall was performed, within which the wind load was taken as the calculated one, due to which the greatest lateral deformations of the tank wall during its construction are possible, which can cause disruption of the technological process of its construction using spiral-winding method.The paper considers tank wall solutions of different diameters (in the range from 10 to 65 m), which have the smallest wall thicknesses adopted in accordance with the recommendations from the Russian standard.Modeling of the tank wall included the preparation of geometric and calculation models. The geometric model is presented in the form of an axisymmetric cylindrical shell, on the outside of which flat ribs are placed at a constant pitch along the shell axis, giving it additional stiffness. The calculation model includes a geometric model of the wall, to which a wind load is applied from the outside, the pressure from which on the tank wall is constant along its height; it is maximum under normal action and decreases to zero under tangential action. Using the calculation model, firstly, a dependence was obtained that reflects the effect of a change in the height of the tank wall on the maximum radial displacements in its base near the supports, and, secondly, the dependence of the maximum radial displacements of the tank wall in its base near the supports, depending on its diameter.The results of the analysis, in particular, showed that the stiffness of the wall obtained on the basis of the spiral-winding method practically does not change with an increase in its diameter (and a corresponding increase in thickness).

Elastodynamic Green's functions for sandwich panels with aluminum foam core and transversely isotropic face sheets using potential functions method

Green's functions of stress and displacement due to wave propagation in a sandwich panel consisting of transversely isotropic face-sheets and aluminum foam core are developed in the present paper. Dynamic partial differential equations of equilibrium for the considered face-sheets and core are expressed in cylindrical coordinates (r, θ, z), and converted into two separate equations using two unknown potential functions. Then, by writing the potential functions as Fourier series in the circumferential direction and using Hankel transform in the radial direction, an analytical solution to the potential functions in Hankel transformed space is developed. Using the boundary conditions and continuity of the problem as well as the place of application of harmonic forces, Green's functions for displacements and stresses in the frequency domain are derived using Hankel's inverse integral transform. These functions are expressed as complex integrals and calculated numerically. To verify the methodology and results, a comparison study is performed for particular cases showing a high level of the accuracy. Green's functions obtained from this paper will give information about the loading models or materials causing the maximum normal stress, shear stress, vertical and radial displacements. In addition, based on the results, with an increase in the core thickness compared to that of face-sheets in a Sandwich panel, an increment in Green's functions of stress and displacement is observed in both real and imaginary parts.

Biomechanical comparison of different internal fixation devices for transversely unstable Mason type II radial head fractures.

Background: The integrity of the radial head is critical to maintaining elbow joint stability. For radial head fractures requiring surgical treatment, headless compression cannulated screw fixation is a less invasive scheme that has fewer complications. The aim of this study was to compare the mechanical stability of different fixation devices, including headless compression cannulated screws and mini-T-plates, for the fixation of transversely unstable radial head fractures. Methods: Forty identical synthetic radius bones were used to construct transverse unstable radial head fracture models. Parallel, cross, and tripod headless compression cannulated screw fixation and mini-T plate fixation were applied. The structural stiffness of each group was compared by static shear loading. Afterward, cyclic loading was performed in each of the three directions of the radial head, and the shear stability of each group was compared by calculating the maximum radial head displacement at the end of the cycle. Findings: The mini-T plate group had the lowest structural stiffness (51.8 ± 7.7N/mm) and the highest relative displacement of the radial head after cyclic loading (p < 0.05). The tripod headless compression cannulated screw group had the highest structural stiffness among all screw groups (p < 0.05). However, there was no significant difference in the relative displacement of the radial head between the screw groups after cyclic loading in different directions (p > 0.05). Interpretation: In conclusion, the biomechanical stability of the mini-T plate for fixation of transverse unstable radial head fractures is lower than that of headless compression cannulated screws. Tripod fixation provides more stable fixation than parallel and cross fixation with headless compression cannulated screws for the treatment of transversely unstable radial head fractures.

Suspension Flux Internal Model Control of Single-Winding Bearingless Flux-Switching Permanent Magnet Motor

A suspension flux internal model control method is proposed to address the problem of the strong coupling of a single-winding bearingless flux-switching permanent magnet motor leading to a significant ripple of the rotor radial displacement. Firstly, based on air-gap magnetic field modulation theory, the stator flux equation considering rotor dynamic eccentricity is established to reveal the relationship between the eccentric rotor and the magnetic field. Secondly, according to the dynamic characteristics of the motor and the variation law of the air-gap magnetic field, the suspension-plane flux is substituted into the rotor dynamic model, and the suspension flux-dynamics internal model and corresponding output are constructed, respectively. Finally, a complete control strategy is established, and the rotor is stably suspended by PWM control. The simulation and experimental results show that the proposed method has better steady-state and dynamic performance than traditional PID control, and the maximum radial displacement ripples of the rotor are reduced by 53% and 50% in steady-state and dynamic operation.

Real-time spatiotemporal characterization of mechanics and sonoporation of acoustic droplet vaporization in acoustically responsive scaffolds.

Phase-shift droplets provide a flexible and dynamic platform for therapeutic and diagnostic applications of ultrasound. The spatiotemporal response of phase-shift droplets to focused ultrasound, via the mechanism termed acoustic droplet vaporization (ADV), can generate a range of bioeffects. Although ADV has been used widely in theranostic applications, ADV-induced bioeffects are understudied. Here, we integrated ultra-high-speed microscopy, confocal microscopy, and focused ultrasound for real-time visualization of ADV-induced mechanics and sonoporation in fibrin-based, tissue-mimicking hydrogels. Three monodispersed phase-shift droplets-containing perfluoropentane (PFP), perfluorohexane (PFH), or perfluorooctane (PFO)-with an average radius of ∼6 μm were studied. Fibroblasts and tracer particles, co-encapsulated within the hydrogel, were used to quantify sonoporation and mechanics resulting from ADV, respectively. The maximum radial expansion, expansion velocity, induced strain, and displacement of tracer particles were significantly higher in fibrin gels containing PFP droplets compared to PFH or PFO. Additionally, cell membrane permeabilization significantly depended on the distance between the droplet and cell (d), decreasing rapidly with increasing d. Significant membrane permeabilization occurred when d was smaller than the maximum radius of expansion. Both ultra-high-speed and confocal images indicate a hyper-local region of influence by an ADV bubble, which correlated inversely with the bulk boiling point of the phase-shift droplets. The findings provide insight into developing optimal approaches for therapeutic applications of ADV.

A Novel Gradient-Weighted Voting Approach for Classical and Fuzzy Circular Hough Transforms and Their Application in Medical Image Analysis—Case Study: Colonoscopy

Classical circular Hough transform was proven to be effective for some types of colorectal polyps. However, the polyps are very rarely perfectly circular, so some tolerance is needed, that can be ensured by applying fuzzy Hough transform instead of the classical one. In addition, the edge detection method, which is used as a preprocessing step of the Hough transforms, was changed from the generally used Canny method to Prewitt that detects fewer edge points outside of the polyp contours and also a smaller number of points to be transformed based on statistical data from three colonoscopy databases. According to the statistical study we performed, in the colonoscopy images the polyp contours usually belong to gradient domain of neither too large, nor too small gradients, though they can also have stronger or weaker segments. In order to prioritize the gradient domain typical for the polyps, a relative gradient-based thresholding as well as a gradient-weighted voting was introduced in this paper. For evaluating the improvement of the shape deviation tolerance of the classical and fuzzy Hough transforms, the maximum radial displacement and the average radius were used to characterize the roundness of the objects to be detected. The gradient thresholding proved to decrease the calculation time to less than 50% of the full Hough transforms, and the number of the resulting circles outside the polyp’s environment also decreased, especially for low resolution images.

Study on the impact of ovality defect on structural stability of CIPP liner of drainage pipeline

Cured-in-Place Pipe (CIPP) is a trenchless pipeline rehabilitation technology commonly used for repairing underground municipal pipes. It effectively, safely, and environmentally friendly resolves drainage pipe leakage and dripping issues by curing a new resin-impregnated liner inside the original pipe. However, in practical applications, ovality defects may occur in CIPP liners due to insufficient inflation, deformation of the original pipe, joint misalignment, and other problems. These defects have the potential to reduce the structural bearing capacity of the liners. To investigate the buckling mechanism of oval liner structures under external water pressure, two sets of OD 600 mm CIPP liner buckling tests were conducted. The critical buckling stress state and buckling mode characteristics exhibited similarities across liners with different initial ovalities. With an increase in the ovality defect of the liners from 0% to 5%, the critical buckling pressure decreased by 10.62%, while the maximum radial deformation displacement decreased by 62%. Existing models have shown an inability to accurately predict the buckling pressure of oval liners with an initial annular gap. Consequently, this study proposes an improved analytical solution for calculating the critical buckling pressure of liners with ovality imperfections under the influence of an annular gap, which aligns well with the experimental data. The conclusions drawn from this study provide substantial data support for ensuring the accuracy and safety of CIPP liner rehabilitation design.

Application of conjugated materials in muscle movement recovery process.

Conjugate materials have a good application effect in muscle movement recovery. This article aims to provide more references for the practical application of conjugated materials in sports recovery. This paper takes the students of the local physical education college as the experimental object, and selects the students who have sports muscle fatigue or injury for the test. In this paper, they are randomly divided into two groups: the experimental group and the control group, with 19 students in each group. The experimental group used the conjugate material in this paper for muscle movement recovery, while the control group used the traditional method for muscle movement recovery. This paper tested the peak torque, total work done, maximum radial displacement, and contraction time of two groups of students after initial exercise and muscle recovery. The experimental results showed that after 80h of muscle movement recovery, the peak torque values of isometric contraction (264.59) and concentric contraction (160.81) of students in the experimental group were higher than those of students in the control group (233.79) and concentric contraction (130.43), and the difference was statistically significant (p < 0.05); the isometric contraction time (30.02) and concentric contraction time (29.31) of the experimental group were also higher than those of the control group (27.31) and concentric contraction time (24.58), which was statistically significant (p < 0.05). This study shows that conjugated materials have a significant effect on promoting muscle recovery. They not only help to increase the peak torque of muscle isometric contraction and concentric contraction, but also increase the time of muscle contraction and improve muscle mass.

Study on the calculation method and structural dynamic response of buried pipeline subjected to external explosion load based on multiphase coupling

When the buried pipeline is subjected to the external explosion load, stress and deformation will occur. When the stress and deformation value exceed a specific range, it will affect the normal use of the buried pipeline. In this paper, a multiphase coupled model of pipeline, soil and fluid within the pipeline is established. The penalty function coupling method is used to describe the load between soil and pipeline and the fluid within the pipeline. By specifying the boundary conditions of the coupled system, the multiphase coupled global solution variational principle function of the soil-pipe-fluid is derived. According to the established multiphase coupled calculation method, the numerical simulation analysis of the response of pipeline to external explosion is carried out. The maximum error of the experimental and numerical simulation results is about 5%, which verifies the accuracy of the multiphase coupled calculation method. The soil-pipeline-fluid multiphase coupled numerical calculation model is established to analyze the response of the buried pipeline under the external explosion load. The results show that during the explosion shock wave propagating in the soil, the peak value of the explosion pressure in different positions in the soil of the gas pipeline is greater than that of the oil pipeline. As for the structural response, the maximum radial displacement value of the oil pipeline is reduced by 3.83 mm compared with the gas pipeline, the maximum stress value is reduced by 3.75%. The maximum radial displacement value of the pipeline with a fluid velocity of 1.5 m/s is 2.65 mm larger than that of the pipeline with a fluid velocity of 1 m/s, and the maximum stress value is increased by 5.72%. The deformation resistance and explosion resistance of the oil pipeline are both stronger than that of the gas pipeline. The higher the fluid velocity, the weaker the pipeline's resistance to deformation and explosion will be.

Comparative Analysis and Experiment Verification of Diamagnetically Stable Levitation Structure

In this paper, a new diamagnetic levitation structure is proposed to explore its potential in the application of sensors and actuators through the study of its levitation and dynamic characteristics. Compared with our old diamagnetic levitation structure, the levitation point, maximum monostable levitation space, horizontal magnetic spring stiffness, and axial resultant force distribution of the new structure are all adjustable. At the same time, the maximum horizontal radial recovery force of the floating magnet could reach 34780 μN, which is 542.41% higher than that of the floating magnet in the old structure. Accordingly, when the range of the horizontal radial displacement is 0 to 15 mm, the maximum axial resultant force of the floating magnet is 439.7 μN, which is only 5.72% of that in the old structure. In experiment, when the floating magnet is blown by nitrogen gas with a flow rate of 3000 sccm, the maximum horizontal radial displacement of the floating magnet is 2.27 mm, which is only 22.976% of that in the old structure. Under the same gas flow rate, the maximum tilt angle of the floating magnet is 0.482°, which is only 3.998% of that in the old structure. In summary, the theoretical analysis, numerical simulation, and experiment results are consistent with each other, which indicates the great potential of the new structure in the application of sensors and actuators.

Tensiomyographic Assessment of Contractile Properties in Elite Youth Soccer Players According to Maturity Status.

Little is known about how muscle contractile properties are affected by biological maturation in elite youth soccer players. This study aimed to determine the effects of maturation on contractile properties of rectus femoris (RF) and biceps femoris (BF) muscles assessed by tensiomyography (TMG) and provide reference values for elite youth soccer players. One hundred twenty-one elite youth soccer players (14.98 ± 1.83 years; 167.38 ± 10.37 cm; 60.65 ± 11.69 kg) took part in the study. The predicted peak height velocity (PHV) was used in order to establish players' maturity status (Pre-PHV, n = 18; Mid-PHV, n = 37; Post-PHV = 66). Maximal radial displacement of the muscle belly, contraction time, delay time, and contraction velocity for RF and BF muscles were recorded. One-way ANOVA showed no significant differences between PHV groups for any tensiomyography variables in RF and BF muscles (p > 0.05). Our results established that maturity status did not show a significant effect in mechanical and contractile properties on RF and BF muscles evaluated by TMG in elite youth soccer players. These findings and reference values can be useful for strength and conditioning coaches of elite soccer academies in order to optimize the evaluation of neuromuscular profiles.