Auxiliary Springs Research Articles

A Novel Tri-Magnet Levitating Bistable Electromagnetic Energy Harvester with Variable Potential Wells to Promote Snap-Through Behavior

To achieve broadband energy harvesting under weak excitations, this paper comprehensively investigates a novel tri-magnet levitating bistable electromagnetic energy harvester with variable potential wells (BEEH-VP). The bistable nonlinear mechanism is realized using the single-sided bipolarity of the ring magnets. Auxiliary springs are integrated into the ring magnets to dynamically self-adjust the spacing of the ring magnets, causing variable potential wells. The analytical model of BEEH-VP is derived and verified experimentally. The performance of the proposed BEEH-VP is compared with that of the bistable electromagnetic energy harvester with featuring fixed potential wells (BEEH-FP). The comparative results clearly demonstrate that the BEEH-VP exhibits superior capabilities in terms of energy output under weak excitation and possesses a broader frequency bandwidth. Bifurcation analysis for the excitation conditions reveals that the proposed structure features complex dynamic behaviors, such as intra-well, chaotic, harmonic inter-well and subharmonic inter-well vibrations. In comparison to BEEH-FP, BEEH-VP requires lower acceleration to perform the snap-through and has a larger vibration amplitude, facilitating improved output performance.

Structural and Passability Analysis of Dual Detection Mode Pipeline Robot

A new pipeline robot with a dual detection mode is built in order to address the issues with the current oil and gas pipeline inspection robots, such as single detection mode, small pipe diameter adaptation range, poor passing ability, and adaptability of the robots in pipelines. The general design of the robot is presented in this paper and the robot’s general construction and operation principles are discussed. The support system, which combines the main and auxiliary springs to achieve common preloading and force analysis, is organized to meet these goals. This paper designs the detection structure with an angle adjustable function. The robot’s motion and dimension restrictions through the bend pipe are examined concurrently. Experimental verification is then completed. The results of the experiments demonstrate that the robot’s structure design and calculations are reasonable, that the robot’s size and motion constraints analysis in the bend pipe is accurate, and that the robot can successfully pass the bend pipe with R ≥ 1.5D. The study’s findings serve as a guide for the development of prototype robots and subsequent robot simulation experiments.

Prediction of Ply Angles of Air Springs According to Airbag Positions and Their Effects on Lateral and Torsional Stiffness

The stiffness in various directions of air springs have a great influence on the stability of high-speed trains. Due to the change in the bogie structure, the required functions of the air springs have also diversified, and the damping of various loading modes such as vertical, lateral, and torsional movements is emerging as important. The stiffnesses are affected by the shape of the air bag, the material, and the ply angles. In this paper, the relationship between the ply angle and the radial position is proposed by equations from deformation modes. The variable angles in the plies were compared and demonstrated in air-spring analysis using the rebar elements. The vertical, lateral, and torsional stiffness of air springs without auxiliary springs were compared between constant ply angles and variable ply angles with respect to the positions. When mainly dealing with the vertical stiffness, the effect of the angle variation was small; however, it was found that it had a large effect of more than 24% and 30% on the stiffness in the lateral direction and torsional direction, respectively.

Active/passive tuning of wave propagation in phononic microbeams via piezoelectric patches

In this paper, size-dependent microbeams made of functionally graded materials (FGMs) with periodic arrays of auxiliary piezoelectric springs are considered small-sized phononic crystals (PCs). The governing equation of motion for the propagation of flexural waves is derived and solved using the transfer matrix method (TMM). Then, the small size effects on the wave propagation in periodic FGM microbeams are investigated. Also, the effects of FGM distribution on the dispersion curves as well as on the frequency ranges and widths of the stop-bands are analyzed. Additionally, by actively modulating the piezoelectric stiffness of the auxiliary springs, tunable wave attenuation is reached via both local resonance (LR) and Bragg scattering mechanisms. The results prove that stop-bands of both LR and Bragg natures can be tuned in microbeams, and tunable wave-attenuation performance can be achieved in different ranges of the frequency spectrum by implementing FGMs and combining it with piezoelectricity. Such findings place this work among the first efforts to provide passive and active control of wave attenuation in size-dependent tiny metamaterials.

Parametric study on power capture performance of an adaptive bistable point absorber wave energy converter in irregular waves

The power capture performance of an adaptive bistable point absorber wave energy converter (WEC) in irregular waves is investigated in this paper. Based on the linear potential flow theory and Cummins equations, the equation of motion for the WEC is established in time domain. Then a parametric study is performed on the power capture performance of the WEC by considering the influences of different wave and system parameters such as the spring combination parameter, the stiffness of auxiliary springs and main springs, the original length value of the main spring, damping coefficient of the PTO systems and the significant wave height. The results show that in an irregular wave, each parameter will have a certain impact on the performance of the device. Appropriate device parameters need to be selected according to actual environmental parameters to ensure that the adaptive bistable WEC has better power capture performance than its linear and conventional bistable counterparts.

Performance Analysis of an Adaptive Bistable Point Absorber Wave Energy Converter Under White Noise Wave Excitation

Performance analysis is conducted for an adaptive bistable point absorber wave energy converter under white noise wave excitation. The adaptive bistable wave power capture mechanism is composed of two oblique springs responsible for bistable characteristics, and two auxiliary springs realizing the ‘adaptive’ feature. White noise wave excitation is adopted to explore the effects of multi-frequency input in absence of different energy distribution characteristics. Time domain simulations are performed based on Cummins equations derived from linear potential flow theory. Results indicate that the adaptive bistable mechanism still bears a better power performance than its linear counterpart which may be well explained by its inherent ‘phase control’ feature in white noise wave excitation. A parametric study is also carried out to investigate how the power capture performance of the adaptive bistable point absorber wave energy converter is affected by main and auxiliary spring stiffness, random phase of wave excitation and power-take-off damping.

Mechanism and sensitivity for broadband energy harvesting of an adaptive bistable point absorber wave energy converter

The adaptive bistable point absorber wave energy converter (WEC) concept proposed by Zhang et al. (Applied Energy 2018(228), pp. 450–467) is further investigated by exploring the underlying mechanism and sensitivity related to the broadband energy harvesting of this device. The mechanism can be explained in two different ways: (i) the broadband power capture is due to the fact that the adaptive bistable mechanism introduces both negative (at low wave frequencies) and positive (at high wave frequencies) stiffness to the device; and (ii) an inherent ‘phase control’ feature is observed especially at low wave frequency region. The variation of initial conditions of floater motion only has an observable influence at intermediate wave frequencies corresponding to chaotic response of the floater. The broad frequency bandwidth can be realized through different combinations of main and auxiliary springs' stiffness. The effects of wave amplitude on broadband energy harvesting can be categorized according to an optimum amplitude (if existing) into a gradual reduction for a larger wave amplitude and a quick drop for a smaller amplitude.

"A" Loop : A New Loop for Management of Impacted or Ectopically Erupted Canines

The ectopic eruption and impaction of permanent canine is a common problem encountered in clinical practice. As maxillary canine is the last permanent tooth to erupt (except third molars), it is most prevalent to be malpositioned or remain impacted due to tooth size arch length discrepancy. The orthodontic treatment of impacted maxillary canine remains a challenge to today's clinicians. The treatment of this clinical entity usually involves surgical exposure of the impacted tooth, followed by orthodontic traction to guide and align it into the dental arch so that it comes into occlusion. Auxiliary springs have been used in orthodontics since long for correction of impacted/unerupted canines or adjacent teeth. Cantilever springs are preferred than the continuous wires as placement of continuous flexible wires for correction of these single tooth malocclusions produces an adverse effect on adjacent teeth. A common disadvantage in all of the loops and techniques mentioned above is that it offers a poor anchorage control in extraction cases. Usually the root of impacted canines is near the cortical bone and needs to be brought into cancellous bone, so as to prevent the resorption and also faster movement of the canine. Keeping these points in mind we designed a loop, which fulfills most of the shortcomings, which are discussed above. This loops is called "A loop” as its shape resembles the shape of alphabet "A”. The design, fabrication, biomechanics, advantages and disadvantages of "A loop” are discussed in this article.

Application of an adaptive bistable power capture mechanism to a point absorber wave energy converter

This work proposes a novel adaptive bistable power capture mechanism, which is applied to a point absorber wave energy converter in regular waves. The adaptive bistable mechanism is realized by two symmetrically oblique main springs (responsible for the bistable characteristics) together with two auxiliary springs (making the bistable system adaptive) and it can adjust the potential function automatically to lower the potential barrier near the unstable equilibrium position. The “adaptive” feature helps solve the low-energy-absorption problem of a conventional bistable wave energy device (whose potential function is invariable in time) caused by the intrawell oscillation in low-amplitude excitation. With a suitable choice of physical and geometric parameters, an adaptive bistable wave energy converter outperforms its linear counterpart while a conventional bistable wave energy device has a poorer performance in low amplitude waves. Even for relatively large waves, an adaptive bistable wave energy converter has a comparable power capture capacity with its conventional bistable counterpart, both of which perform better than a linear wave energy converter especially in the low wave frequency region.

Experience with Contemporary Tip-Edge plus Technique–A Case Report.

Aim of this case report was to analyze the treatment mechanics of Tip-Edge Plus appliance. A recent modification to the Tip-Edge bracket system now enables torque and tip corrections to be achieved without the use of auxiliary springs (Side-Winders). Tip Edge Plus employ nickel titanium for root uprighting by using the additional slot of the bracket. The Aesthetics and efficiency in Stage III of Tip Edge Plus are far superior. Tip Edge Plus Appliance is easier to keep clean without auxiliary springs, more comfortable without the added

영화관 의자용 음향진동자극 시트의 개발

The global movie industry is continuing rapid growth through application of the latest technology. 3D movies are being produced and shown for a more effective viewing experience. Special chairs for audiences are being experimentally manufactured and installed for the greatest viewing effect. This special chair has a structure that applies vibrating stimuli to specific parts of the body by attaching vibration transducers to theater chairs and synchronizing it with each scene of the movie. In a previous study, it has been confirmed that we can analyze the vibration transfer characteristics of sponge seats through the application of an experimental modal analysis method and obtain design variables easily. In this paper, we examine the major design parameters needed in the development of a foaming sponge seat in which auxiliary springs are inserted to improve the vibration transfer effect of a chair seat. Through analyzing several prototypes by applying experimentation as well as the experimental modal analysis method, it was confirmed that the effect of vibration transfer can be improved through the use of an auxiliary member.

Versatile Auxiliary Orthodontic Spring for Orthodontic Correction of Impacted Teeth

The ectopic eruption and impaction of permanent canine is a frequently encountered clinical problem. Lowest incidence of impacted canines 0.27% reported in literature relates to Japanese sample population. In Americans and Israeli, it is 1.5% while the highest incidence of 7.9% was reported among Iceland population. Maxillary canine, since last in eruption sequence (except third molars), is most prevalent to be malpositioned due to tooth size arch length discrepancy (TSALD). Auxiliary springs have been used in orthodontics since long for the correction of impacted or unerupted canines or adjacent teeth. Cantilever springs are preferred than the continuous wires as placement of continuous flexible wires for correction of these single tooth malocclusions produces adverse effects on adjacent teeth, i.e. flattening of the arch and/or openbite in that region which eventually require more time for correction. In Begg’s light force appliance, various methods have been used, including the use of light wire springs, springs soldered to the heavy labial or palatal base wire and mousetrap loops bent in the archwires. With the use of these methods orthodontist had no precise control of magnitude and direction of force. Ballista spring, a unilateral spring made up of round wire and is tied into one of the molar tube, lacks the versatility in its use. Seong-Sang used auxiliary wire comprising 0.014 inch Australian Willcock wire. 1n 1995, Kornhauser et al used labial spring auxiliary. Orton in 1995 used a combination of the lower removable appliance and gold chain since this can be readily fabricated. Magnets are also utilized for the correction of impacted canines. Bowman and Carano introduced the Kilroy spring in 2003. Auxiliaries used previously lacked the versatility of their use with different fixed appliances, such as round and rectangular molar tubes and were not applicable for different malpositions of the canine or adjacent teeth. Their uses were restricted to specific conditions. Present article describes the fabrication of a self-stabilizing, self-locking, versatile auxiliary orthodontic spring (VAOS).

Current products and practice: Tip-Edge Plus

A recent modification to the Tip-Edge bracket system now enables torque and tip corrections to be achieved without the use of auxiliary springs. This article describes the new Tip-Edge Plus.

The “tip-edge” torquing mechanism: A mathematical validation

The Tip-Edge (TP Orthodontics, LaPorte, Ind) bracket is unique among orthodontic brackets because it can be used in combination with rectangular archwire to torque teeth, not through activation of the archwire itself but through the action of auxiliary springs that are active in the tip plane. The purpose of this report is to describe the way in which a tipping couple generates a secondary torquing couple and the resulting path traced by the root apex and to express those actions mathematically. The magnitude of forces applied by the auxiliary spring to the tooth apex is calculated on the basis of an experiment. (Am J Orthod Dentofacial Orthop 2001;119:632-9)

Rectangular wire and third-order torque: A new perspective

The Differential Straight Arch technique, more commonly known as "Tip-Edge" (TP Orthodontics Inc.), uses a modified edgewise type bracket to allow differential tooth movement. As bracketed teeth incline toward their finishing positions, the geometry of the arch wire slot causes the vertical slot dimension available to the arch wire to increase. Advantage has been taken of this facility, to evolve an entirely new torquing system for final finishing, during the root correction phase. Instead of increasing rectangular arch wire size to fit the arch wire slot, as with conventional edgewise brackets, the Tip-Edge method reduces the vertical arch wire slot dimension to achieve a precise, three-dimensional relationship to a full-sized rectangular arch wire. The active component is provided by auxiliary springs. The method, which awaits mathematical analysis, is described and illustrated with two case reports.

Auxiliary springs in continuous arch treatment: Part 2. Appliance use and case reports

In the second part of this series, three clinical examples are presented to illustrate the use of auxiliary space-closure springs with clinically manageable moment-to-force ratios and new canine brackets to accommodate these springs within the framework of conventional and straight-wire 0.018-inch appliance systems. Eligiloy retraction spring models (0.1650 inch x 0.02150 inch) in the edgewise mode were developed for translational movements along a main archwire. The effects of different preactivation bends for influencing intraarch anchorage are shown for the conditions of reciprocal closure, posterior protraction, and anterior retraction.

Auxiliary springs in continuous arch treatment: Part 1. An analytical study employing the finite-element method

This report describes the results of a finite-element analysis with ANSYS (Version 4.3) from Swanson Analysis Systems and 1 mm-long, 2-D elastic beam elements to modify and refine the designs of maxillary and mandibular springs for space-closure management. This system permitted static analysis by means of modern software systems instead of expensive and cumbersome mechanical bench studies. Our examination of anterior and posterior reactions led to what we believe are optimal designs with clinically manageable moment/force ratios and new canine brackets that accommodate these springs within the framework of conventional and straight-wire appliance systems. Three degrees of freedom were used at each node for translations in the x and y directions and a rotation about the z axis, producing 182 elements with 183 nodes for the mandibular model and 146 elements with 147 nodes for the maxillary model. Elgiloy retraction spring models (0.1650 inch x 0.02150 inch) in the edgewise mode were developed so that the effects of three different preactivation bends could be refined by computer analysis. Sixty-four analyses were performed for each spring, with each of three angle bends (theta 1, theta 2, and theta 3) varied from 0 degrees to 45 degrees in 15 degrees increments. The employment of this computer method promises to simplify the design and development of complex interacting orthodontic systems. Clinical cases are presented in Part 2 of this series, which illustrates the application of auxiliary springs.

BEDDTIOT: The state of the art, 1980

Abstract The Begg-Edgewise Diagnosis Determined Totally Individualized Orthodontic Technique was developed in an attempt to assimilate and enhance the best aspects of the Begg and various Edgewise techniques, and to eliminate their deficiencies. The appliance is a combination of six different narrow brackets with horizontal slots (.022″ × .028″) and 0°, 3°, 7°, 11°, 17° and 22° degrees of torque. The brackets have a vertical, slot (.020″ × .020″) for auxiliary springs. In some cases double Edgewise buccal tubes (.022″ × .028″) on molar teeth are used with about 24° of angulation between the two tubes; triple tubes may be employed if required in the upper arch for extra-oral force. The appliance is illustrated with the records of seven cases presented, including non-extraction and extraction treatment plans. The cases illustrate the technique’s utilization in minimum, moderate and maximum anchorage situations, and various combinations of elastics, together with sectional Edgewise wires. The use of square and ribbon arch wires in preference to Edgewise configurations is also discussed.

Useful clinical technique for upper canine retraction and retention.

Two appliances are described. The first is a lingual arch carrying a Nance bulb and auxiliary springs for retraction of upper canines or premolars. The second is a retention appliance constructed at the chairside from Coe “Dental Guards”.

Microcellular Urethane— Processing and Applications

The basic chemical and physical proper ties of microcellular urethane are described. The methods of processing and the produc tion sequence are outlined. The ability of microcellular urethane to replace rubber and other materials in auxiliary springs, damping devices, and seals is discussed. A number of examples of current applications, particularly in the automotive industry, are given. A direct comparison between the compres sion, shear, cold flow, permanent set, fatigue strength, and effect of temperature on natural rubber and microcellular urethane is given.