COIL SPRING COUPLING: CALCULATION OF TORSIONAL STIFFNESS AND COIL STRENGTH

2021 ◽  
pp. 30-37
Author(s):  
V. M. Zyablikov ◽  
A. A. Shirshov
Keyword(s):  
Torsional Rigidity ◽  
Calculation Model ◽  
Torsional Stiffness ◽  
Coil Spring ◽  
Coupling Calculation

The design of the coupling is considered in detail, its possibilities for connecting misaligned shafts are indicated. The interaction of the spring turns with the teeth of the half-couplings is considered in detail. A scheme of deformation (exaggerated) of the coils during the transmission of torque is proposed, according to which a calculation model is selected to determine the torsional rigidity of the coupling and the strength of the coils. It is shown that during the operation of the coupling, the coils of the spring not only bend, but also twist, increasing the stiffness, while their strength is estimated by an equivalent voltage. Misalignment of the connected shafts, as well as an increase in the gap between the coupling halves, leads to a decrease in torsional rigidity and an increase in stresses in the spring turns.

scholarly journals Magnetorheological Elastomer-Based Variable Stiffness Flexible Coupling for Vibration Isolation.

2021 ◽  
Author(s):  
Thaer Mahmoud Syam ◽  
Ahmed Hegazi ◽  
Asan Muthalif ◽  
Yousif Badri
Keyword(s):  
Magnetic Field ◽  
Torsional Vibration ◽  
Vibration Isolation ◽  
Volume Fraction ◽  
Torsional Rigidity ◽  
Magnetic Field Effect ◽  
Variable Stiffness ◽  
Torsional Stiffness ◽  
Smart Composite Materials ◽  
The Magnetic Field

Magnetorheological elastomers (MRE) are smart composite materials by which their mechanical properties, such as stiffness, are changed under a magnetic field. In this article, the introduction of a variable stiffness coupling (VSC) fitted within a shaft for torsional vibration isolation that would adapt and change its attenuation frequency range is presented. The VSC concept on torsional vibration isolation is tested experimentally. MRE samples with 40% volume fraction are fabricated and manufactured using a 3D mold design and fixed within a coupling in a shaft to investigate the magnetic field effect on the torsional rigidity. Impact hammer test is conducted along with an accelerometer to obtain the transmissibility factor analysis. Results show that the vibration level decreases when the magnetic field increases. The 1st natural frequency of the system happened at 26 Hz and moved to 28 Hz when the applied current increases from 0 mT to 12.38 mT. MRE torsional stiffness increased from 37.4 N.m/rad to 61.6 N.m/rad when the current increased from 0 mT to 12.38 mT. The torsional damping coefficient showed a fluctuation in its variation as the damping effect of MR elastomer is ignored

Elastic Torsion in the Presence of Initial Axial Stress

1950 ◽  
Vol 17 (4) ◽  
pp. 383-387
Author(s):  
J. N. Goodier
Keyword(s):  
Cross Section ◽  
Axial Stress ◽  
Torsional Rigidity ◽  
Torsional Stiffness ◽  
Lateral Buckling ◽  
Initial Tension ◽  
Open Section ◽  
Thin Walled ◽  
The Cross

Abstract The torsional rigidity, for small elastic torsion, of bars of thin-walled open section, is, in general, altered by initial tension, compression, bending, or other axial stress. This appears in the increase of torsional stiffness of strips due to tension, in the decrease to zero in open sections which buckle torsionally as columns, and also has an influence on lateral buckling of beams. This paper contains an extension of the Saint Venant solution for ordinary torsion to the problem of torsion in the presence of initial axial stress with any distribution on the cross section. The results are confirmed by tests, and validate the intuitively derived formulas which are in use.

Analysis of the Extension-Twist Coupling in Hygrothermally Stable Star Beam Composites

2011 ◽  
Author(s):  
Sean Muder ◽  
Robert Haynes ◽  
Erian Armanios
Keyword(s):  
Analytical Model ◽  
Axial Force ◽  
Torsional Rigidity ◽  
Torsional Stiffness ◽  
New Family ◽  
Stiffness Properties ◽  
Twist Rate ◽  
The Relationship

An approximate analytical model is utilized to examine the extension-twist coupling and torsional stiffness properties of star beams constructed with a new family of hygrothermally stable optimized stacking sequences. The relationship between axial force and the twist rate is used to quantify the results. The results show that there is a decrease in torsional rigidity corresponding to an increase in extension-twist coupling. The new stacking sequences allow for the addition of more substrips while maintaining comparable levels of extension-twist coupling with beams constructed from prior benchmark layups. This results in higher levels of torsional stiffness for comparable levels of extension-twist coupling in star beams made of the new optimized stacking sequences.

Size Effects of Hair-Sized Structures – Torsion

2004 ◽  
Vol 261-263 ◽  
pp. 11-22 ◽  
Author(s):  
Pin Tong ◽  
Fan Yang ◽  
David C.C. Lam ◽  
Jun Wang
Keyword(s):  
Size Effects ◽  
Torsional Rigidity ◽  
Higher Order ◽  
Torsional Stiffness ◽  
Length Scale ◽  
Warping Function ◽  
Thin Wall ◽  
Order Partial Differential Equation ◽  
Strain Gradients ◽  
Scale Parameters

Conventional strain-based mechanics theory does not account for contributions from strain gradients. Failure to include the strain gradient contributions can lead to underestimates of stresses and size-dependent behaviors in small-scaled structure [1]. This paper focus on the structural size effects on torsion of cylinders. The torsional stiffness of cylinders can be higher than conventional expectation when the cylinder size is in the nanometer - or micron-scale. Following the Saint-Venant theory of torsion, we established the equation of torsion in terms of the warping function on the basis of the nano-mechanical theory of elasticity. The torsional equations contain two higher order material length scale parameters and two conventional Lame constants. The equilibrium equation is a fourth order partial differential equation which can be reduced to two second order equations. Two formulations in terms of pseudo warping function and stress function are presented. Closed-form solutions for circular and thin wall section and series solutions for rectangular microbars have been obtained. The total torque depends only on the stresses conjugated to the strain and is only implicitly dependent on the higher order stress metrics. The solution reveals that the torsional rigidity is dependent on the higher order length scale parameters and strain gradients and increases asymptotically upward when the cylinder size is reduced to the size of the higher order length scale material parameters. The increase is most marked for thin walled cylinders, stiffening to more then 10 times the conventional value when the cylinder size is near that of the higher order length scaled parameters.

scholarly journals Healing of sub-critical femoral osteotomies in mice is unaffected by tacrolimus and deletion of recombination activating gene 1

2021 ◽  
Vol 41 ◽  
pp. 345-354
Author(s):  
T-Y Liu ◽  
M Bartnikowski ◽  
AC Wu ◽  
M Veitch ◽  
KA Sokolowski ◽  
...  
Keyword(s):  
T Cell Activation ◽  
Cell Activation ◽  
Bone Fractures ◽  
Ex Vivo ◽  
Torsional Rigidity ◽  
Bone Volume ◽  
Torsional Stiffness ◽  
Long Bone ◽  
Mouse Strains ◽  
Tissue Volume

Clinical management of delayed healing or non-union of long bone fractures and segmental defects poses a substantial orthopaedic challenge. There are suggestions in the literature that bone healing may be enhanced by inhibiting the activities of T and B lymphocytes, but this remains controversial. To examine this matter in more detail, sub-critical-sized segmental defects were created in the femora of mice and it was assessed whether there might be a benefit from the administration of a Food and Drug Administration (FDA)-approved drug that blocks T cell activation (tacrolimus). Defects were stabilised using an internal plate. In certain groups of animals, 1 mg/kg or 10 mg/kg tacrolimus was delivered locally to the defect site for 3 or 7 d using an implanted osmotic pump with a silicon catheter directing drug delivery into the defect area. Healing was monitored by weekly X-ray and assessed at 12 weeks by mechanical testing, µCT and histology. Radiographic and histological evaluations revealed that 100 % of defects healed well regardless of tacrolimus dosage or duration. A comparison of healed C57BL/6 and Rag1−/− femora by µCT and ex vivo torsion testing showed no differences within mouse strains in terms of bone volume, tissue volume, bone volume/tissue volume ratio, shear modulus, torsional rigidity or torsional stiffness. These data failed to support an important role for tacrolimus in modulating the natural healing of segmental defects under those experimental conditions.

Torsional Design Method of Bottom Frame Structure with Irregular Plane

2014 ◽  
Vol 716-717 ◽  
pp. 460-464
Author(s):  
Hong Yu Deng ◽  
Bai Tao Sun
Keyword(s):  
Design Method ◽  
Torsional Rigidity ◽  
Center Of Mass ◽  
Time History ◽  
Calculation Model ◽  
Frame Structure ◽  
Contrast Model ◽  
Torsional Response ◽  
Finite Element Software ◽  
Bottom Frame

For the study of irregular plane adverse impacts on the bottom frame structure seismic performance, in this paper, a serious damaged bottom frame structure in Wenchuan earthquake is taken as the research object,and a comparative calculation model is designed and elasto-plastic time-history analysis is carried out on the use of ABAQUS finite element software. The calculation results show that: the stiffness center of floor with irregular plane does not coincide with the center of mass, this eccentricity will produce torsional response under horizontal earthquake action. Bottom frame shear layer has strong stiffness at the center, around the lack of lateral load resisting member will cause interlayer torsional rigidity insufficient, further increasing the torsional response of structures, aggravated the damage. The lateral stiffness ratio under the same conditions,the design method of the contrast model is more reasonable, and has lighter damage under the the same intensity grade, improve the seismic capability of the structure, and provides the ideas of design method of this kind of structure.

Influence Analysis of Coupled Neutronics and Thermo-Hydraulics on Steady-State Characteristics of Supercritical Water-Cooled Reactor

2012 ◽  
Vol 472-475 ◽  
pp. 278-283
Author(s):  
Juan Chen ◽  
Tao Zhou ◽  
Zhou Sen Hou ◽  
Wan Xu Cheng ◽  
Can Hui Sun
Keyword(s):  
Steady State ◽  
Supercritical Water ◽  
Cross Sections ◽  
Power Distribution ◽  
Coupled Model ◽  
Calculation Model ◽  
Coolant Temperature ◽  
Coupling Condition ◽  
Coupling Calculation ◽  
Supercritical Water Cooled Reactor

the coulped neutronics and thermo-hydraulics model for supercritical water-cooled reactor (SCWR) is developed by internal coupling method. It is based on the two group neutron diffusion equations and the one-dimensional junction thermal analysis mode, in which the cross sections used for SCWR are generated by Dragon tool. Compared with the calculation results based on the non-coupling calculation model, the steady state characteristics under coupling calculation condition are detailed analyzed by considering parameters feedback at each axial node. The results show that, as coupled model is chosen its axial power distribution would give an obvious deviation from the cosine function that used for non-coupled model. Although the cladding temperature at most of the axial nodes rises with a shifted power peak, the maximum cladding temperature is finally decreased. For the above coupling condition, the maximum cladding temperature would appear at the external assemblies with lower coolant temperature but not at inner assemblies with higher coolant temperature. As the detailed description for coupling characteristics of supercritical water-cooled reactor is given, a certain theory reference for its system safety could be provided.

PSEUDOELASTIC BEHAVIOR OF COIL SPRING MADE OF A HIGH-DAMPING Cu-Zn-Al ALLOY

1981 ◽  
Vol 42 (C5) ◽  
pp. C5-1019-C5-1024
Author(s):  
K. Sugimoto ◽  
Y. Nakamura ◽  
L. Delaey
Keyword(s):  
Al Alloy ◽  
Coil Spring ◽  
Pseudoelastic Behavior

A fuzzy neural network approach for modeling the growth kinetics of FeB and Fe2B layers during the boronizing process

2018 ◽  
Vol 106 (6) ◽  
pp. 603 ◽  
Author(s):  
Bendaoud Mebarek ◽  
Mourad Keddam
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Fuzzy Neural Network ◽  
Treatment Time ◽  
Calculation Model ◽  
Average Error ◽  
Network Approach ◽  
Neural Network Approach ◽  
Fuzzy Neural ◽  
Kinetics Of

In this paper, we develop a boronizing process simulation model based on fuzzy neural network (FNN) approach for estimating the thickness of the FeB and Fe2B layers. The model represents a synthesis of two artificial intelligence techniques; the fuzzy logic and the neural network. Characteristics of the fuzzy neural network approach for the modelling of boronizing process are presented in this study. In order to validate the results of our calculation model, we have used the learning base of experimental data of the powder-pack boronizing of Fe-15Cr alloy in the temperature range from 800 to 1050 °C and for a treatment time ranging from 0.5 to 12 h. The obtained results show that it is possible to estimate the influence of different process parameters. Comparing the results obtained by the artificial neural network to experimental data, the average error generated from the fuzzy neural network was 3% for the FeB layer and 3.5% for the Fe2B layer. The results obtained from the fuzzy neural network approach are in agreement with the experimental data. Finally, the utilization of fuzzy neural network approach is well adapted for the boronizing kinetics of Fe-15Cr alloy.

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