Axial Torque Research Articles

3D external shape analysis and barycentremetry can provide early signs of progression in adolescent idiopathic scoliosis.

Our objective was to analysis the barycentremetry, obtained from the external envelope reconstruction of biplanar radiographs, in adolescent idiopathic scoliosis (AIS) and to determine whether assessing would help predict the distinction between progressive and stable AIS at the early stage. A retrospective study with a multicentre cohort of 205 AIS was conducted. All AIS underwent a biplanar X-ray between 2013 and 2020. Inclusion criteria were Cobb angle between 10° and 25°; Risser sign lower than 3; age higher than 10years; and no previous treatment. A 3D spine reconstruction was performed, and the barycentremetry parameters were computed, i.e., the center of mass position at the apex and the axial torque at the apex, the upper and lower junction. A severity index, helping to distinguish stable and progressive AIS, was computed on the first radiograph, and weighted according to these parameters. A clinical and radiographic monitoring determined if AIS were classified such a stable or progressive scoliosis. One hundred and sixty-two AIS were included (i.e., 87 were classified as stable and 75 as progressive). The apex center of mass position was different between the stable and progressive AIS groups (6mm, SD = 4mm for the whole cohort; 5mm, SD = 4mm for stable AIS versus 7mm, SD = 4mm for progressive AIS; p = 0.02). In AIS thoracic, the specificity and positive predictive value of the severity index increased by 19% and 16%, respectively, by adding the apex vertebral axial torque. Early assessment of the external envelope from biplanar X-ray reconstruction of idiopathic scoliosis showed that the apex centre of mass position was significantly different between progressive and stable scoliosis. The inclusion of the axial torque of the apex vertebra in the severity index is promising to help the clinician distinguish between stable and progressive thoracic AIS at an early stage. II - Prognostic studies.

Mechatronic technological system based on CNC and intelligent mechatronic mechanism

A mechatronic technological system (MTS) has been developed. It consisting of a CNC metal-cutting machine tool and a mechatronic spindle, made on the basis of an intelligent mechatronic mechanism (IMM). The main elements of the technological system – the CNC and IMM devices – are parts of a single hierarchical, two-level control system, representing, respectively, the upper and lower control levels in this system. The upper control level – the CNC device – ensures stabilization of the kinematic parameters of machining (displacement, speed, acceleration) and their software change in accordance with the CNC control program. The lower control level – the IMM device – ensures stabilization of the power parameters of mechanical machining (cutting axial force and torque) and their software change in accordance with the technological requirements for the surface quality and the physical-and-mechanical state of the surface layer of the machined parts. At both control levels (the upper and lower ones), closed automatic control systems “by deviation” of the adjustable kinematic (upper control level) and power (lower control level) parameters of mechanical machining are functioning. Moreover, the automatic control system of the lower control level of the hierarchy in relation to a similar automatic control system of the upper control level, implements the method of automatic control “by disturbance”. This, in addition to directly ensuring surface finish and surface integrity, allows improving the quality of stabilization of kinematic cutting parameters at the upper control level. Experimental studies of MTS were carried out when machining parts from various materials (steel, polymer composite materials, superhard crystals and stones, other difficult-to-machine materials).

A Direct Contour Control Method for Free-Form Surface Machining Trajectories Based on Coordinate Transformation

The requirement for high-speed and high-precision contouring with free-form surfaces in the CNC machining process is increasing. The contour error is an essential criterion for the quality of CNC machining. For the problem of contour error control, the present research is mainly based on position tracking, and the control method directly aiming at contour control has not been well studied. This paper proposed a new type of coordinate transformation-based direct contour control method (CT-DCC) for free-form surface machining trajectories. By real-time monitoring of the contour error and the foot point of the free-form parametric trajectory, the contouring task is decomposed into the contour error control task in the normal direction and the velocity control problem in the feed direction. Using coordinate transformation, the output commands of the two tasks are converted to the axial motion command. CT-DCC completely eliminates position tracking in the traditional control to achieve direct control of the contour error, which provides a new solution for the contour control problem of free-form surface machining. Both the axial velocity control and the axial torque control-based CT-DCC scheme were studied, and the two-axis and three-axis direct contour controllers were tested. The simulation and experiment results show the feasibility of the proposed method.

Modeling analysis on the influence of the gyrostatic moment on the motion of a charged rigid body subjected to constant axial torque

Modeling analysis on the influence of the gyrostatic moment on the motion of a charged rigid body subjected to constant axial torque

Acoustic radiation force on a cylindrical composite particle with an elastic thin shell and an internal eccentric liquid column in a plane ultrasonic wave field

Abstract A model with three-layer structure is introduced to explore the acoustic radiation force (ARF) on composite particles with an elastic thin shell. Combing acoustic scattering of cylinder and the thin-shell theorem, the ARF expression was derived, and the longitudinal and transverse components of the force and axial torque for an eccentric liquid-filled composite particle was obtained. It was found that many factors, such as medium properties, acoustic parameters, eccentricity, and radius ratio of the inner liquid column, affect the acoustic scattering field of the particle, which in turn changes the forces and torque. The acoustic response varies with the particle structures, so the resonance peaks of the force function and torque shift with the eccentricity and radii ratio of particle. The acoustic response of the particle is enhanced and exhibits higher force values due to the presence of the elastic thin shell and the coupling effect with the eccentricity of the internal liquid column. The decrease of the inner liquid density may suppress the high-order resonance peaks, and internal fluid column has less effects on the change in force on composite particle at ka > 3, while limited differences exist at ka < 3. The axial torque on particles due to geometric asymmetry is closely related to ka and the eccentricity. The distribution of positive and negative force and torque along the axis ka exhibits that composite particle can be manipulated or separated by ultrasound. Our theoretical analysis can provide support for the acoustic manipulation, sorting, and targeting of inhomogeneous particles.

Analysis of the influence of assembly deviation and repeated assembly on sealing performance of detachable aviation pipe joint

Detachable pipe joints are an important component of aviation hydraulic systems, and their sealing performance is related to the safety and reliability of the entire machine. This paper focuses on the impact of assembly deviation and repeated assembly on the sealing performance of 35 MPa aviation pipe joints. The sealing performance of pipe joints was quantitatively evaluated using the sealing contact strength theory, and the influence of assembly deviation on sealing performance was studied using the finite element method. Designed a repeated tightening test device for pipe joints and conducted repeated tightening tests. A method for analyzing the initial loss of axial force, usage loss, and friction torque during repeated tightening of pipe joints has been established. Finally, combining experimental data and simulation calculations, the influence of repeated tightening on the sealing contact strength was analyzed. This study provides an analysis method and influencing law for the sealing performance of 35 MPa level detachable aviation pipe joints under assembly deviation and repeated assembly. The research content can provide theoretical guidance for the assembly process design of pipe joints.

Investigation of the effect of ultrasonic vibration on the performance of the friction drilling by FEM simulation

The friction drilling process is very important in various industries such as automotive, aerospace, and oil and gas industries. Therefore, they have always sought to find methods to improve this process. One of these methods is to optimize the application of ultrasonic vibrations in the process, and limited research has been done in this regard. The current research aims to investigate the effect of ultrasonic vibrations simultaneously with the parameters of drilling on the friction drilling process to optimize this process with the help of finite element simulation. Due to the nature of the complex transformations of the process, a Coupled Eulerian–Lagrangian model of the process was first created in the Abaqus software. Then, the process simulation was carried out in the presence and absence of ultrasonic vibrations. Rotational speed, feed rate, and amplitude of vibrations are the influencing parameters, and sheet temperature and axial force, and torque applied to the tool are the parameters investigated in this research. The results show that higher rotation speed and lower feed rate lead to a reduction of axial force and torque. Also, the application of ultrasonic vibration reduces up to 50.48% the axial force and up to 46.67% torque, and this reduction is improved by increasing the range of vibrations. The optimal mode was selected After analyzing 12 different modes based on the lowest amount of axial force and torque on the pin. It was found that the ideal mode occurs at a feed rate of 4.23 m/s and a rotation speed of 3000 rpm, with a 20-µm range. These findings and optimizing drilling parameters bring new horizons in material bonding techniques in various industries.

Evaluating High‐Pressure Torsion Scale‐Up

Increasing sample dimensions in high‐pressure torsion (HPT) processing affects load and torque requirements, deformation distribution, and heating. Finite‐element modeling (FEM) and experiments are used to investigate the effect of technical parameters on the scaling up of HPT. Simulations confirm that axial load and torque requirements are proportional to the square and the cube of the sample radius, respectively. The temperature rise also displays a pronounced dependency on the radius. Decreasing the diameter‐to‐thickness ratio can cause heterogeneity in strain distribution along the thickness direction at the edges of the sample. Such heterogeneity is governed by friction conditions between the material and the lateral wall of the anvil depression. Simulation of HPT processing of ring‐shaped samples shows that it is possible to reach more homogeneous distribution of strain and flow stress in the processed material. Experiments using magnesium confirm a tendency for strain localization in the early stage of HPT processing but increasing the number of turns increases the homogeneity of the material. The embodied energy in HPT processing is discussed.

Mechanical Properties and In Vitro Corrosion Behaviors of Biodegradable Magnesium Alloy Suture Anchors

Biodegradable suture anchors based on Mg-Nd-Zn-Zr alloy were developed for ligament-to-bone fixation in rotator cuff surgeries. The Mg alloy anchors were designed with structural features of narrow tooth and wide tooth, and simulated through finite element analysis (FEA). Meanwhile, the corrosion behaviors of the Mg alloy anchors were studied by immersion test and the mechanical properties were investigated by measuring the maximum torque and pull-out force. The simulation result showed that the wide-tooth anchor exhibited more a uniform stress distribution and lower shear stress in the torsion process, suggesting a satisfactory torsional resistance of this structure. Meanwhile, the wide-tooth anchor exhibited a lower Von-Mises stress after applying the same pull-out force in the simulation, indicating a higher resistance to pull-out failure of the anchor. The result of the immersion test indicated that the wide-tooth anchor exhibited a slightly slower corrosion rate in Hank’s solution after 14-day immersion, which was beneficial to enhance the structural and mechanical stability of the biodegradable suture anchor. Furthermore, the results of the mechanical properties test demonstrated that the wide-tooth anchor showed superior performance with higher maximum torques and axial pull-out forces before and after corrosion. More importantly, the axial pull-out force and maximum torque for the wide-tooth anchor decreased by 5.86% and 8.64% after corrosion, which were significantly less than those for the narrow-tooth anchor. Therefore, the wide-tooth suture anchor with lower corrosion rate, higher mechanical properties and structural stability is a promising candidate for ligament-bone fixation in the repair of rotator cuff injuries.

Optical radiation force and torque of light-sheets on a cylindrical particle near an infinite boundary

This work aims to extend the previous studies on the optical radiation force and torque for a cylindrical dielectric particle to the case near an infinite boundary. Without loss of generality, the two-dimensional cylindrical object is assumed to have an arbitrary shape and be immersed in any light-sheet beam of arbitrary wave front. The partial-wave series expansion method in cylindrical coordinates and the method of images are utilized to derive the exact expressions for the axial and transverse radiation force and torque functions, which are dependent on the beam shape coefficients of the incident light-sheet and the scattering coefficients characterized by the boundary conditions at the surface. Numerical computations are performed for a circular cylindrical particle illuminated by a two-dimensional plane wave and a two-dimensional Gauss beam, respectively, with particular emphases on the size parameter, the refractive index, the particle-boundary distance, the beam waist and the offset shifts. The radiation force will increase in magnitude and reverse its direction under selected conditions. When the absorptive cylindrical particle is shifted off-axially with respect to the beam axis, it will be rotated counterclockwise or clockwise by the radiation torque. The results obtained in this work have potential applications in non-contact particle manipulation and transportation using optical tweezers.

Spinal axial torque assessment after surgical correction in adolescent idiopathic scoliosis: a new approach to 3D barycentremetry and mass distribution based on biplanar radiographs.

Barycentremetry in adolescent idiopathic scoliosis (AIS) allows the distribution of masses and their loading of the spine to be studied. In particular, the axial torque on the spine has been studied in AIS, but not after surgical correction. Spinal axial torque was studied in AIS before and after surgery. All AIS (Lenke 1 and 3) who underwent posterior spinal fusion surgery at our center in 2019 were included retrospectively. AIS underwent frontal and sagittal biplanar radiographs in the free-standing position before surgery, 4months after surgery, and at the last follow-up. Their spine and external envelope were reconstructed with validated methods. Spinal axial torque at the apex and the upper and lower end vertebra was calculated. Finally, the preoperative and postoperative values were compared to a previously published reference corridor for asymptomatic subjects. Twenty-nine patients were included (54 ± 11° Cobb angle, 15 ± 2years old at surgery). The surgical procedure decreased the Cobb angle by 36° ± 11° and decreased the spinal axial torque at the upper end vertebra by 2.5N/m (95% CI = [1.9; 3]; p < 0.001), at the apex by 0.6 N/m (95% CI = [0.4; 1]; p = 0.004), at the lower end vertebra by 2N/m (95% CI = [1.5; 2.8]; p < 0.001). Compared to 95th percentile of torque, which was previously evaluated in asymptomatic subjects, more than 90% of patients had higher values at the upper and lower end vertebrae before surgery. Postoperatively, 62% of patients still had higher torque at the upper end vertebra than asymptomatic subjects, while only 38% patients showed abnormal values at the lower junction. Results of this study confirm that AIS patients show abnormally high spinal axial torque, especially at the end vertebrae, and that this parameter is normalized postoperatively for only a small number of patients.

Influence of tool positions variation on axial force, torque sensitivity, mechanical and microstructure properties of Al/Cu dissimilar FSW

ABSTRACT Study on tool offset must be necessary to minimise IMCs formation and mechanical properties enhancement. Tool offset has a significant variations in the instantaneous force and torque are measures for the welding process. Increasing in the offset means more % of Al. This means softer IMCs formation and so increasing in offset distance decrease on load in the spindle/Z-axis and X-axis torque. A precise critical offset towards Al plate could result in a defect-free joint and superior mechanical performance. 1.5 mm offset gives smooth variations in the peaks, indicating a uniform distribution of the intermetallic compound, smooth weld surface and defect-free weld leads to better mechanical properties. In comparison to the Al base metal, the weld sample had more tensile and yield strength of 95% and 100%, respectively in case of optimised offset of 1.5 mm. 1.5 mm offset give maximum compressive strength (97.5% of the Al BM), maximum tensile properties and micro-hardness (176.2HV) due to fine grain with Al 44 μm and Cu 42 μm. As the grain size decreases so it helps to increase tensile properties and the strength of the joint depends on the offset distance and formation of the suitable amount of the intermetallics.

Explicit Formulas for the Deformation of Chiral Porous Circular Beams in Gradient Thermoelasticity

Chirality and porosity are characteristic properties of nanostructured materials. Their effects on the mechanical behaviour of structural elements, such as shells, plates and beams, cannot be disregarded. In this paper, we study the thermoelastic deformation of a chiral porous circular beam loaded with an axial force and torque. The beam is also under the action of a constant temperature field. The analytical solution is obtained using the results established in a paper recently published by the Author within the context of the strain gradient theory proposed by Papanicopolous. In the constitutive equations, the chirality is introduced by a material constant parameter and the porosity is described by means of a scalar function. Displacements, microdilatation function, and stress and strain fields are expressed in explicit form and in terms of engineering constants. Explicit formulas of the stiffness of chiral porous circular beams are presented and the effects of right and left chirality are discussed.

Numerical and analytical models of the mechanism of torque and axial load transmission in a shock absorber for drilling oil, gas and geothermal wells

The paper proposes an improved design of a shock absorber used in drilling deep oil and gas and geothermal wells with polycrystalline diamond compact (PDC) bits. The proposed innovations successfully combat the dangerous phenomenon of self-excited vibrations, which can lead to malfunctions such as stick-slip and whirling of the drilling tool. Most conventional drill shock absorbers are designed to only absorb longitudinal vibrations, which was sufficient when using roller cutter bits for the drilling process. However, the design features of PDC bits and the phenomenon of interaction of their cutters with interlayered rocks during deep drilling impose new requirements on the properties of the drill shock absorber. To protect the downhole tool from abnormal torque values and torque oscillations, it is proposed to equip the shock absorber with a special torque transmission unit in the form of a fourteen-thread self-releasing screw pair. This unit is capable of transforming increases in external torque into increases in the force that loads the elastic element of the shock absorber. The numerical and analytical models of the mechanism of transferring external axial load and torque to the elastic element of the drill shock absorber are constructed. The distribution of contact pressures on the interacting surfaces of the screw pair and the distribution of equivalent stresses in the screw pair parts are analysed. The strength of the proposed drill shock absorber assembly was evaluated using the Huber-von Mises energy criterion. The dependence of the load transmitted to the elastic element of the shock absorber on changes in the external torque and external axial force is investigated. In general, it is determined that the external load is distributed evenly between all turns of the screw pair, and the limit state of the parts of the proposed assembly is not reached even under high-torque operating load. The obtained analytical dependencies will allow to effectively determine the required strength and stiffness of the elastic element of the drill shock absorber at the design stage. The obtained analytical results were verified using a finite element model.

ELASTIC AND STRENGTH PARAMETERS DETERMINATION OF POLYMER COMPOSITE MATERIALS AND CYLINDRICAL SHELLS

The article presents a method for layout optimization in polymer composite materials that allows to assess their strength. In order to assess the stress-strain state of each layer, an orthotropic elasticity model is used assuming that the fibers in the material are parallel. The behavior model of polymer composite materials is based on the Hashin criterion, which makes it possible to separate the destruction mechanisms of matrix and fiber. The strength assessment was carried out in accordance with the structural approach involving studying the strength of each layer separately. The parameters of the deformation model and the Hashin strength criterion were determined based on the results of testing. Tests were carried out on unidirectional polymer composite materials samples cut at angles of 0, 90 and 45° to the direction of reinforcement. The verification was based on the results of bending tests of polymer composite materials samples. Verification showed high proximity between the calculation results and the experimental data. A method for selecting the layout angles of each layer of polymer composite materials has been developed making it possible to calculate the greatest strength of the cylindrical shell under various external loads. The method involves determining the stresses in each of the polymer composite materials layers, as well as Hashin indicators corresponding to the destruction of the fiber or matrix under tension or compression. Based on the indicator values, the optimal angle and layout pattern can be selected, providing the greatest margin of safety for the shell. This method allows for a preliminary assessment of the safety factor of cylindrical shells made of polymer composite materials based on the experimentally determined elastic parameters of the material and the parameters of the Hashin strength criterion. The method takes into account the angle and layout of the prepreg under the influence of internal pressure, axial compressive force and torque.

Analysis of the Matching between the Electric Propulsion Conical Motor in Electric Aircraft and the Propeller Based on Axial Force and Torque

Analysis of the Matching between the Electric Propulsion Conical Motor in Electric Aircraft and the Propeller Based on Axial Force and Torque

Research Status and Trend of Axis-torsion Two-Component Force Senso

Axis-torsion two-component force sensor can simultaneously detect axial force and torque component information. With the progress of modern engineering technology and the improvement of the requirements for measurement accuracy and dynamic response ability, the sensor is widely used in many fields such as industry, national defense science and technology, and medical treatment. The axis-torsion twocomponent force sensor based on the measurement principles of resistance strain type, capacitance type and magnetostrictive effect is introduced. Because the resistance strain type axis-torsion two-component force sensor has a high degree of accuracy, good stability, simple structure and strong anti-electromagnetic interference ability, the resistance strain type axis-torsion two-component force sensor is the most widely used and the most technologically mature class of sensor. The structural characteristics of the elastic body of the combined and integral axis-torsion two-component force sensor are summarized. At present, the elastic body structure of the axis-torsion two-component force sensor is mainly studied and improved. The purpose is to improve the sensor’s measurement accuracyand reduce the inter-dimensional coupling error, so as to achieve accurate measurement in practical applications. The application status of the axis-torsion two-component force sensor in the cutting force detection, torque coefficient detection of high-strength bolted joints, and quantitative analysis of traditional Chinese medicine acupuncture techniques were analyzed. Finally, combined with the research and application status of the axis-torsion two-component force sensor, the development trend of the axis-torsion two-component force sensor is prospected.

The Improvement of Blade Element Momentum Theory in Horizontal Axis Wind Turbine Performance Analysis

The present work uses the blade element momentum theory method for evaluating the performance of horizontal axis wind turbine. The wind turbine performances are described in term of the thrust coefficient CT, torque coefficient CQ and the power coefficient CP. The blade element momentum theory (BEMT) represents the wind turbine performance prediction method as result of combining two methods, namely the blade element theory (BET) and the momentum theory (MT). Both theories are able to formulate the axial forces and torques which work on the blade. Equating axial force and torque formulated by BET is equal axial force and torque by MT, makes one allows the axial induction factor and the angular induction factor a^’, the unknown quantities, can be defined and furthermore the wind turbine performances can be evaluated. The BEMT method used here is the combination of BEMT. The implementation this method as the tool for predicting the wind turbine performances are work well. However, for wind turbine configuration need a little adjustment, especially in setting the hub radius rh where the blade element momentum theory starts to make calculation from the inner blade to the tip. The high pitch angle and a relatively a large chord length at rh, make the BEMT fail to converge. In addition to the present work found that the three wind turbine performance coefficients are formulated by using the momentum theory is less accurate compared with BET formulation.

Effect of leading edge and trailing edge serrations on a rotating Wells turbine

Wells turbine used for wave and wind power generation is known to generate loud noise during its operation. Aerodynamic noise reduction is an important issue in the design of the turbines. Since aerodynamic noise depends highly on behavior of the vortices around the turbine and the flow structure in the wake region, understanding of behavior of the unsteady flow past a rotating turbine plays important role. In this study, we modeled Wells turbine with normal (solid) blades and serrated turbine. To visualize the flow separation and vortex generation near the rotating turbine at its startup, LES simulations were performed by using moving mesh and transient inlet condition. In addition to the detailed flow structure around the turbine, the results show that the axial torque of the turbine increases with respect to the monotonically increasing inlet velocity. It is also found that positive axial torque generated for the normal and trailing edge serrated turbines as the inlet flow velocity increased, but no torque was obtained for the leading edge serrated turbine due to flow separation at the leading edge.

Development of the simulation model for testing the axial torque distribution in an electric vehicle with the dual-motor layout

BACKGROUND: The market of vehicles using electricity as an energy source demonstrates significant growth. Currently, there are more than twenty million electric vehicles worldwide. Leading manufacturers give the high priority to development of electric transport due to lower vehicle service costs, ease of driving as well as zero emissions in environment and almost complete noiselessness at motion. In addition, using the full-wheel drive in an electric vehicle makes it possible to improve off-road capability, ensures more balanced chassis control, precise following the path and constant accuracy of steering. AIMS: Ensuring increase in vehicle course stability, delivering the maximal torque regarding vehicle motion conditions and slip control in dual-motor layouts of electric vehicles. METHODS: In order to solve the given task, implementation of the special-purpose algorithm of torque distribution between driving axles of an electric vehicle is assumed. The paper presents the development of the simulation model of a vehicle, built in the Simcenter Amesim software and considering dynamic properties and features of the vehicle. This model was implemented into the Labcar hardware-in-the-loop facility. RESULTS: The simulation result is comparison with the data obtained during ground testing of the prototype and confirming the aim of simulation model development, in particular the capability of revision and preliminary setting up the algorithm of torque distribution between driving axles of a vehicle. CONCLUSIONS: Based on the results of the testing of the developed facility, it can be concluded that the developed simulation facility is suitable for solving the simulation tasks including research, debugging and primary calibrations of the algorithm of torque distribution between driving axles of a full-wheel driven electric vehicle. The errors at simulation of operation modes relevant to longitudinal and lateral dynamics of the prototype is no more than 7.5% that complies with the simulation aims.