Steel Coil Spring Research Articles

Acoustical performance of steel coil springs for vibration isolation

The acoustical performance of a set of commercially available steel coil springs was evaluated supporting a rigid structure above a slab on grade. The vibration isolation of this simple system is determined by exciting the on-grade slab with a tapping machine and measuring the resulting vibration transmitted into the isolated rigid structure above. Insertion loss of the system is determined by comparing the vibration level on the rigid structure with and without the vibration isolators under the same dynamic forces. The test results reveal the natural frequency, damping ratio, and insertion loss of the system as a function of the loading on the coil springs. The results also reveal the presence of surge frequencies (or wave resonances) that significantly degrade the system performance of at these specific frequencies, which are usually greater than 50 times the natural frequency of the loaded steel spring. Because of potential structure-borne noise transmission through steel coil springs into the supporting structure, designers should be cautioned when considering the use of steel springs to support equipment that can generate strong tonal vibrations in the surge frequency region of the springs.

Design Analysis and Optimization of Coil Spring for Three-Wheeler Vehicles Using Composite Materials

The quest for lightweight, efficient, and corrosion-resistant coil springs for vehicle suspension systems has led to the exploration of alternative materials beyond traditional steel. This study delves into the potential of composite materials, particularly carbon/epoxy and carbon/carbon nanotube/epoxy, as replacements for conventional steel coil springs in light vehicles. Through a comprehensive analysis of mechanical properties under static and dynamic loading conditions, the study demonstrates the superior performance of composite springs compared to their steel counterparts. After optimization, the deflection of the carbon/carbon nanotube/epoxy and carbon/epoxy springs decreased to 15.003 mm and 18.703 mm, respectively, and the maximum shear stress decreased by 64.63% and 62.2%, respectively. Likewise, strain energies increased to 2.3644 and 3.5616, respectively. The springs were also studied under dynamic conditions, and the result showed these springs have the ability to perform in dynamic conditions. The carbon/carbon nanotube/epoxy composite emerged as the frontrunner, exhibiting remarkable improvements in shear stress, fatigue life, strain energy, and deformation properties. The study highlights the ability of carbon/carbon nanotube/epoxy composite springs to significantly reduce weight, enhance efficiency, and extend fatigue life, making them a promising alternative for next-generation vehicle suspension systems.

Design of Composite Disc Spring for Automotive Suspension with using Numerical Simulation

This paper investigates the replacement of a conventional steel coil spring with a composite disc spring with the aim of minimizing its weight. Simulation in the CAD system Siemens NX 12 was used to determine the composite disc spring’s behavior. The regression functions were stated based on the numerical simulation. Based on the regression functions the solution with the minimum weight was found using software programmed in Matlab. The prototype discs were manufactured from carbon fibre prepreg. Their load-deflection characteristics were tested and compared with the designed values. The experimental results show that using this solution reduces the weight by about 30% in this case.

Structural Analysis on the Coil Spring of Motorcycle Suspension System

The motorcycle suspension system is one of the crucial components. It helps to support the motorcycle’s weight, isolate the vibration level caused by road imperfection, and keep the wheel in contact with the road surface. Therefore, the performance of suspension system needs to be enhanced to ensure the ride comfort and safety of riders. Coil spring is one of the essential parts of motorcycle suspension system. In this study, two different materials of coil spring are being focused include steel alloy and carbon fiber reinforced plastic (CFRP). The geometry of the coil spring is the existing design in the market. The static structural analyses are carried out to determine the directional deformation of y-axis, equivalent stress and equivalent elastic stress analysis of the corresponding coil spring material. The obtained results are discussed. It is found that the steel coil spring has better performance for the existing coil spring design. The directional deformation, equivalent stress and equivalent elastic strain of steel coil spring are considered at the lower side, which is 0.029357mm, 2003MPa and 0.010051mm/mm respectively. In this study, it is observed that the number of turns of coil spring should be increased to enhance the performance of CFRP coil spring.

An investigation into the mechanism of high-order polygonal wear of metro train wheels and its mitigation measures

High-order polygonal wear wheels have been detected on metro express train operating on one metro line in China, which cause fatigue failures of steel coil springs in the primary suspension. A series of tests and theory analysis were conducted to figure out the mechanism of wheel high-order polygonal wear. The wheel out-of-roundness (OOR) measurement results show that the wheels exhibit polygonal wear with 12–14 harmonics, which are very different from other metro train wheels reported in the literature. The investigation results indicate that the first bending vibration of the wheelset is the root cause of wheel high-order polygonal wear. Rail corrugation with a wavelength of 200 mm in the 1/3-octave band on sharply curved tracks is the main excitation source of the first bending vibration of the wheelset. The formation process and key influencing factors of wheel high-order polygonal wear are analysed in detail. Three measures are suggested to mitigate the formation of wheel high-order polygonal wear.

Design and Fabrication a Lightweight Spring Made of Natural Rubber for a Motorcycle’s Shock Absorber

This research aims to design and fabricate a spring made of natural rubber for a lightweight motorcycle’s shock absorber. This study is carried out in four main steps. First, a stiffness property of a steel coil spring and a damping property of a commercial shock absorber were tested using an Instron® material testing machine and a test rig. Second, six different types of rubber compounds (A-1, A-2, A-3, B-1, B-2, and B-3) were formulated and the best compound was selected to use for a rubber spring. Third, the rubber spring was designed and analyzed using the finite element method to investigate the best model. Finally, a prototype of the rubber spring was fabricated and tested. The steel coil spring was replaced by the rubber spring and tested for its damping property within a real shock absorber. The results of the prototype testing showed that the weight of the rubber spring was lower than the steel coil spring about 48%. The stiffness property of the rubber spring was higher than the steel coil spring around 43% and the damping property of the shock absorber using rubber spring was higher than the damping property of the shock absorber using steel coil spring about 6%. The rubber spring provided more advantages than the steel coil spring for its good corrosion resistance, lightweight, and ease of maintenance. However, the implementation of the rubber spring in the real motorcycle and its fatigue life should be studied in the next future.

The compression specificity of plant tissue.

The aim of this study was to determine the compression characteristics of nonhomogeneous plant materials with a complex morphological structure (beetroots, celery roots, and potato tubers), to compare the analyzed samples with the compression characteristics of reference materials (homogeneous isotropic structural materials: steel coil spring and vulcanized rubber), and to determine the influence of the compression rate on stress in compressed samples. Structural materials and plant materials clearly differed in compression characteristics. Excluding the short initial compression phase, the compression curves for the steel coil spring and vulcanized rubber were straight parallel lines, and the higher the crosshead speed, the higher the lines' location in the diagram. In tests conducted on plant materials, the rate of changes in compression force increased throughout the experiment with an increase in crosshead speed. The greatest variations in compression force resulting from differences in crosshead speed were observed in potato samples. The apparent retardation times determined in the developed rheological model ranged from 0.079 s for the steel coil spring to 6.863 s for potatoes.

Vibration and noise studies on wind turbine generator for reduction of vibrations and noise

Purpose Wind power is the one of best natural resources to meet the demands of electricity in India. In this regard, one of engineering college in Visakhapatnam has procured wind turbine generators of 200 kWp and got these installed on the rooftop of the college buildings for research and power generation. After starting the mills, huge vibrations were experienced by the staff and students in the laboratories and classrooms. So, the purpose of this paper is to carry out vibration and noise studies on wind turbine generator to identify the problem for high vibrations and suggest a novel method for vibration reduction. Design/methodology/approach Experimental vibration and natural frequency investigations are carried when wind velocity around 6.0 m/s using frequency analyzer, impact hammer, condenser microphone and accelerometer. An attempt is made to reduce the vibration and noise level of wind turbine generator by inserting a steel coil spring of 300 mm length having 20 turns in series with turnbuckle D shackle assembly, which is used to connect the wind turbine generator to the hook mounted on slab. Findings A high vibration velocity of 9.9 mm/s was observed on at base frame of wind turbine generator. The natural frequencies of hook and slab are observed in between 15 to 20 Hz from the natural frequency test. A high noise of 94.67 dBA is observed at a distance of 1 m from the base of wind turbine generator along the rotational axis of rotor. After modification to the baseline, WTG the vibration and noise levels are reduced to 4.8 mm/sec and 77.76 dBA, respectively. Originality/value This is the first time to study the huge vibrations generated in wind turbine generators installed on the rooftop of the college. Developed a novel methodology to reduce the vibrations by inserting a steel coil springs in turnbuckle D shackle assembly of wind turbine generators. After modification, wind turbine generator are running successfully without any high vibrations.

Effect of Cocoa Administration on Osteoblast Counts and Alkaline Phosphatase Levels During Orthodontic Tooth Movement in Rats

Introduction: The cocoa effect on osteoblast activity during orthodontic tooth movement remains unknown. To analyze the effect of caffeine in cocoa on osteoblast counts and alkaline phosphatase (ALP) levels during orthodontic tooth movement. Materials and Methods: The subjects used in this study were 24 male Sprague–Dawley rats aged 2.5–3 months. They were divided into treatment and control groups (n =1 2). A three-spin stainless steel coil spring with a 35 cN orthodontic force was stabilized on the maxillary incisors. The rats in the treatment group were given 4.8 g of cocoa powder with 2.7 mg of caffeine. All the subjects were euthanized in four consequent time periods (0, 1, 7, and 14 days), and tissue specimens were stained with hematoxylin-eosin. Osteoblasts were observed and counted under a light microscope with an Optilab camera at 400× magnification. ALP levels were examined through ELISA. Data were analyzed through two-way ANOVA followed by LSD post-hoc test. Results: Significant differences were observed in the control and treatment groups and the time of observing osteoblast count and ALP levels (P

Effect of magnetization on anelasticity of compression steel coil spring

Effect of magnetization on anelasticity of compression steel coil spring

Fabrication and experimentation of FRP helical spring

In present scenario, the automobile industry sector is showing increased interest in reducing the unsprung weight of the automobile & hence increasing the fuel Efficiency. One of the feasible sub systems of a vehicle where weight reduction may be attempted is vehicle- suspension system. Usage of composite material is a proven way to lower the component weight without any compromise in strength. The composite materials are having high specific strength, more elastic strain energy storage capacity in comparison with those of steel. Therefore, helical coil spring made of steel is replaceable by composite cylindrical helical coil spring. This research aims at preparing a re-usable mandrel (mould) of Mild steel, developing a setup for fabrication, fabrication of FRP helical spring using continuous glass fibers and Epoxy Resin (Polymer). Experimentation has been conducted on fabricated FRP helical spring to determine its strength parameters & for failure analysis. It is found that spring stiffness (K) of Glass/Epoxy helical-spring is greater than steel-coil spring with reduced weight.

Characterization of Residual Stresses on Steel Coil Springs via X-Ray Diffraction Techniques

Characterization of Residual Stresses on Steel Coil Springs via X-Ray Diffraction Techniques

Evolution of treatment mechanics and contemporary appliance design in orthodontics: A 40-year perspective.

Until the early 1970s, successful treatment with the Begg technique and the Tweed edgewise technique required tedious wire bending. The introduction of Andrews' straight wire appliance changed that, and it was one of the most significant contributions in the history of orthodontics. The straight wire appliance significantly reduced the amount of wire bending and also brought along other options in treatment mechanics. Retraction of the canines with elastic chains and ligature wires became more common. Sliding mechanics in place of closing loops became the method of space closure for a significant number of clinicians. Edgewise force levels were initially used to close spaces; however, it was soon observed that lighter forces were more effective with sliding mechanics. Along with these changes, it became apparent that compensation in the appliance was needed, depending on the type of malocclusion and particularly with varying extraction sequences. Various appliance designs were developed to accommodate changes in mechanics and force levels. These modifications improved tooth positions at the end of treatment as long as the brackets were properly placed. These major changes in appliances, force levels, and treatment mechanics can be traced back to the work of Dr Lawrence Andrews and the straight wire appliances.

Residual Stress Gradients in AISI 9254 Steel Springs Submitted to Shot Peening and Heat Treatment for Increased Fatigue Resistance

The presence of surface and subsurface residual stresses in steel components has a significant influence on fatigue resistance. In the present work, surface modification of AISI 9254 steel coil springs by heat treatment and multiple shot-peening procedures was investigated. Samples were characterized in the as-coiled, quenched, quenched and tempered, as well as submitted to single and double shot peening treatments. Depth resolved residual stress profiles were determined by X-ray diffraction combined with electrolytic dissolution of the steel. Fracture analysis was performed subsequent to fatigue tests by scanning electron microscopy. It was possible to show that double shot peening led to an increase in compressive stresses in the immediate sub-surface region, which improved fatigue resistance relative to the other tested conditions.

Comparison of Characteristics of the Components Used in Mechanical and Non-Conventional Automotive Suspensions

The paper presents the comparison of the characteristics of spring and damping components used in conventional and non-conventional automotive suspensions. The conventional suspension is based on steel coil springs and hydraulic dampers with fixed characteristics. As an example, the adaptive non-conventional suspension shows the characteristics of hydropneumatic suspension components (suspension are constantly being developed and is now based on mechatronic control systems of damping characteristics). The paper summarizes the advantages and disadvantages of these solutions.

Experimental and Numerical Investigation of SUP12 Steel Coil Spring

Coil springs made of spring steel often have high yield strength which enables them to return to their original form after a significant force is applied. Specific application of steel spring in automotive is ruled by industrial guideline, for example, Japanese Industrial Standard (JIS), Daewoo Engineering Standard (EDS) and Daihatsu Technical Standards (DTS). This study attempt to investigate the characteristics of a coil spring type used in automotive i.e. SUP12 where the analysis approach was done systematically using experimental and numerical methods. The experimental part was intended to verify the SUP12 springs material properties (spring constant, yield strength and tensile strength) are within standard for spring steels, JIS G 4801(1984). The SUP12 spring underwent tensile testing in accordance to JIS Z 2201(2010). Later, finite element simulation was performed using HYPERWORKS (Ver. 11) software to predict the steel spring under displacement conditions as per specific customer requirement i.e. at full rebound, curb length and full bump. The resulting experimental data indicates that the tested SUP12 passed the minimum requirement as per standard. On the other hand, finite element results show that the spring meets the customer requirement within small deviation. This suggested that the systematic verification by experiment and numerical analysis approach on such spring is practical by spring maker.

Loss Tunable Long-Period Fiber Gratings Controlled by Electromagnet

We present microbend long-period fiber gratings that can be used as electrically loss-tunable band-rejection filters. The tunability of wavelength-selective loss is based on variable perturbation of the fiber induced by an electromagnet in combination with a steel coil spring. A dynamic loss amplitude of 11 dB is obtained and the response time measured is 16-18 ms.

Magnetic-force-induced long-period fiber gratings

A novel formation method of a long-period fiber grating (LPFG) based on a magnetic-force-induced microbend is proposed and experimentally demonstrated. The LPFG employs a permanent magnet that exerts transversal force to the fiber by attracting a steel coil spring. The transversal force causes periodic microbending to the fiber, and therefore the transmission wave attenuates at the core-to-cladding mode resonance. This device has advantages of ease of fabrication, reconfigurability, and available for any type of fiber.

Research on the dynamic performance of ship isolator systems that use magnetorheological dampers

Isolator systems on ships should ideally be able to simultaneously reduce low frequency vibration response and high frequency shock response. Conventional isolator systems are unable to do so. To solve the problem, a new style isolator system was created. This isolator system consists of a steel coil spring component and a magnetorheological (MR) damper component working in parallel. Experiments on this isolator system were carried out, including tests of vibration reduction and shock resistance. The vibration load frequencies were set from 1–15 Hz, and force amplitudes from 2.94∼11.76 kN. The maximum shock input acceleration was 20 g, and impulse width was 10ms. Both the vibration and shock loads were applied using MTS Systems Corporation’s hydraulic actuators. The experimental results indicated that the isolator system performs well on system vibration response, with resonance humps of the vibration response obviously reduced after using the MR damper. For the shock experiment, the attenuation of shock response was much faster with increased MR damping. The MR damper’s effect on shock moments was very different from its performance in vibration mode. The correlation between MR force and control current was not as evident as it was during vibration loads.

An investigation of the forces used by clinicians to open spaces with coil springs

Abstract Aims To determine the forces applied by coil springs used to open spaces for blocked out lateral incisors, and to compare the actual forces used with clinicans’ concepts of an ‘ideal’ force. Methods Twelve postgraduate orthodontic students (7M, 5F) and 12 orthodontic tutors (9M, 3F) participated in this study. They were asked to state what they considered was an ideal orthodontic force, and then to cut appropriate lengths of stainless steel and nickel titanium open coil springs to open spaces for blocked out maxillary and mandibular permanent lateral incisors on a typodont set-up. The forces generated by the open coil springs were measured and compared to the stated ideal forces. Results The mean ideal force was 76.75 g (Range: 25–200 g). The mean applied force was 314 g (Range: 21–519 g). There were no significant differences in the forces used by the male and female postgraduates, but the male tutors used a significantly higher force than the male postgraduate students (p = 0.007) and the female tutors (p < 0.001). The female tutors used a significantly lower force than the female postgraduates (p = 0.024) and the male postgraduates (p = 0.003). Higher forces were produced by the stainless steel coil springs in both arches (Maxillary arch: p = 0.007; Mandibular arch: p < 0.005). Conclusions The clinicians could not agree on an ideal force to open spaces for blocked out lateral incisors. There were substantial differences between the forces applied by the coil springs and the forces considered by the clinicians to be ideal. There were large differences in the forces used by the different groups of orthodontists.