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Crack analysis on coil spring is intended to simulate stress, fatigue life, SIF mode I, II, J-Integral, and fatigue crack growth rate. Simulations were carried out using the Ansys Static Structural approach. The material used was tested for its composition and obtained SAE 9260 steel material is. The simulation results in conditions without crack show that the stress concentration point occurs in the 2nd coil according to the location of the coil spring fracture with an equivalent value of von misses 1236.1 MPa below the ultimate tensile strength value of SAE 9260 material. The results of the stress intensity factor value show that mode II shows the highest value was KII=171.11 MPa mm , compared to the value of KI=97.175 MPa mm . This is following the analysis of the number of cycles and the fatigue crack growth rate in mode II which has a lower number of cycles of 97500 cycles compared to mode I which is 677700 cycles, while in mode II it has a critical crack size value of 10.28 mm followed by a drastic decrease in strength. The maximum value of J-Integral for the given crack is 0.33962 mJ/mm2 which is located at the end of the crack. [ABSTRACT FROM AUTHOR]

MacPherson suspension is widely used because of its simple mechanism. However, the side load that appears is a weakness of the MacPherson suspension. The purpose of this study is to reduce the load that arises from the side using MacPherson type L suspension. This study used several stages, namely the L type model and using finite element method software. The suspension is pressed down and at the top of the suspension spring will be seen the force that arises on the x, y, and z axes to simulate the side loads that arise on the top of the spring. The formula is based on analysis and the L type coil spring is designed taking into account the effect of the design variable on the force axis. In the FEM simulation, the direction of the x and y axes is obtained. MacPherson type L with spring 13 is the one whose value is close to zero, which is the most stable spring the y direction is 475.96 N and for the z direction is 4482.5 N. [ABSTRACT FROM AUTHOR]

Nylon coil springs are thermally controlled linear actuators. They have a perspective application as artificial muscles. This article describes thermal experiments that were conducted on samples to determine thermal properties of these coiled springs. The experiments were performed in a temperature regulated environmental chamber. Measurements correctly shown negative value for the coefficient of apparent thermal expansion. Results of these experiments will be used to validate numerical models. [ABSTRACT FROM AUTHOR]

Lean manufacturing is a systematic methodology to minimize waste while maximizing resource utilization which helps business become more effective and competitive in the marketplace. Lean manufacturing is about the enthusiasm for waste elimination. Any business can remain competitive if it is flexible enough to continuously and systematically improve its manufacturing process by eliminating waste, optimize processes, and cut unnecessary cost. This review aims to discuss a wastage assessment method that has been used to implement lean manufacturing across all manufacturing sectors like automotive, electronics, plastic, textile, food, dairy, even services. Specifically, it investigates which are the most common lean tools to be utilized and which has an impact on an organization's performance. In this context, waste is defined as unproductive manufacturing practices by which it does not add value to the product or services and customers are not willing to pay. A comparison of lean tools was made and discussed to analyse the effectiveness of the tool's performance. [ABSTRACT FROM AUTHOR]

The selection of material for any product plays a critical role in every manufacturing processes. Choosing a suitable material among several alternatives is a challenge. A careful investigation must be conducted into the material selection process, as any failure that occurs in the material will end up in the failure of the entire product. The quality and standard of the product are weighed more than the financial aspect of any component. In this aspect, in this paper, proper material shock absorber coil spring material is chosen using the DEAR Algorithm in a novel way. A shock absorber coil spring is considered as one of the most important components in the suspension system of any vehicle. Suitable material must be selected, otherwise it will lead to the fatigue failure of the vehicle. The best performance from the alternative material is to be found by subjecting the coil spring to fatigue without any considerations over the financial aspect. To avoid any complications, material selection is a complex process, and to that end, a systematic method called the DEAR Algorithm is used in this work. Using this Multi-Objective Optimization (MOO) technique, ASTM grade A228 is picked as the suitable material for the shock absorber coil spring without providing weightage to any specific attribute. The results are justified using reports from analysis along with analytical calculations and confirmed by the average validation method corresponding to the desired characteristics. The DEAR algorithm is applied over the analysis report once again in a novel way. The similarity of all the findings demonstrates the DEAR algorithm's superior efficiency and accuracy. [ABSTRACT FROM AUTHOR]

In core areas of the construction industry, such as e.g., the areas of housing, power engineering and transport, a significant amount of construction minerals is consumed. In the Czech Republic, there are approximately 20·109 tons of verified reserves of construction minerals and about 55·106÷60·106 tons of them are extracted annually. Mined minerals must be first treated (crushed, sorted, etc.) before being used in the production of concretes, mortars and blocks, which places high demands on handling and transporting them. For the vertical technological transport of large quantities of materials in mining, preparation and processing plants, quite often, with very constricted working surfaces, a special belt conveyor design known as 'HAC System' or 'Sandwich belt conveyor' can be used. This paper presents the structural design of a spring mechanism, the purpose of which is to create a compressing force acting on the top belt of a vertical belt conveyor. The individual grains of transported material, supported by the bottom belt and covered by the top one, are subjected to normal forces induced by compression force. Friction forces are then generated between the contact surfaces of the material grains and both conveyor belts. For the safe operation and trouble-free transport of granular materials, the conveyor idler rollers, attached to the frames of the segment, must be pressed against the surface of the conveyor belt by a force the size of which does not fall below the limit value. The minimum volume of the contact force must ensure that the grains of the material located in the space between the top and bottom belts, travelling in the vertical section of the belt conveyor, do not move backwards from the movement of the conveyor belts due to their own weight. A laboratory testing device to test top belt compression uses two types of compression coil springs, each one with different values of spring stiffness. The theoretically calculated results and laboratory-obtained values of the compressive force for the two types of redesigned coil springs are listed in Table 1 and Table 2. The obtained results of the experimentally measured compression forces for the given type of spring, generated by vertical movement of the vertically sliding segment called the 'Testing equipment of the compression mechanism for the top belt', which is proportional to the height of the cross-section of the belt filling, are presented in Table 3 and Table 4. [ABSTRACT FROM AUTHOR]

Various elastic elements are widely used in mechanical engineering structures: springs, shells, membranes, etc. In this case, the most widespread are springs - an elastic element designed to create a concentrated load. The spring can be made of any material with sufficiently high strength and elastic properties (steel, nickel, titanium alloys, bronze, plastic, wood, etc.). The main material for the manufacture of springs is spring steel (steel 70, steel 65G, steel 55S2, steel 50HFA, steel 60S2XA, etc.). The following requirements are imposed on the springs: high strength and elasticity, reliability of operation, high relaxation resistance and cyclic endurance, the ability to maintain their technical characteristics when working in various environments. [ABSTRACT FROM AUTHOR]

The Automotive suspension system is deployed to absorb the shock load vibrations due to undulations of the road surface. For vehicles like car, Helical coil springs along with dampers are used in the suspension system. It is expected to perform its function without affecting the stability, steering or handling of the vehicle. The suspension springs belong to the open coil type. The conical spring is a type which has an advantage in the fact that it has a compact structure and good stability, and it is used for bearing larger load and vibration attenuation. This paper aims to assess the performance of Stainless-steelconical springs if used in four-wheeler suspension system. The values of Spring Stiffness, Deflection, Critical Buckling Load and Relative Critical Deflection are calculated for the conical springs and compared with the helical springs. The CAD model of the springs was done using Solid Works and the Finite Element Analysis was done using ANSYS Workbench. The static analysis was performed. The Load and Boundary conditions were specified. The Total Deformation, Factor of Safety, Equivalent Stress, and Maximum Shear Stress of the springs were noted. The results obtained are compared with those of a conventional open coil spring and applicability of the constructed springs to the chosen vehicle is studied depending on the results obtained. [ABSTRACT FROM AUTHOR]

The paper focuses on replacing the front suspension system of a three wheeler vehicles that are presently seen making use of torsion bar suspension in front suspension. The torsion bar suspension system was earlier used in the early 1990s and late 2000s until then the helical coil suspension came into existence for a lot many vehicles being successfully replaced as it provided better feasibility and maintenance than those seen in torsion bar suspension system. Here, in this project currently a vehicle with payload capacity of 4500N, three wheeler mini-door is taking into application. It has ground clearance of 250mm from the ground level. It was verified both mathematically and analytically which of the designs off different materials pave excellent properties close enough to replace Torsion Bar Suspension. CAD model of the helical spring was done in CATIA, followed by ANSYS Simulation with proper conclusion. This project focuses on designing a helical coil for front suspension for those three wheeler vehicles which are still using Torsion Bar Front Suspension in today's condition as a replacement. The spring was designed by following the methods given in V.B. Bhandari that can withstand the vehicle weight along with payload capacity of 990Kg, that the vehicle can sustain, using different material compositions like 54SiCr6, 50CrV4, ASTM A229 apart from those used in torsion bar suspension, at a lower price and with an objective to provide better facilities that torsion bar cannot provide. Equivalent stress, shear stress analysis have been carried out using ANSYS on the designs proposed by allowing a deformation of 166 mm for set stiffness 25KN/mm as per reference papers and previous research work, and checked out of the three which spring provide the optimum results from the different materials and were selected accordingly. [ABSTRACT FROM AUTHOR]

Automobiles have been used to transport public and goods. Automobile technology has been developed drastically in the last decade. In general, many accidents are happening due to inexperienced driving and heavy traffic. And the car bumpers mostly getting damaged in accidents which cost more for owners. It is observed that the causalities during vehicle accidents are very high when compared to the deaths. It is very important to prevent accidents and protect the driver and occupants of the car. To prevent such kinds of problems, we have designed a bumper system that is placed at the bumper frame. Our designed bumper system consists of a hollow cylinder, spring coils, shaft, flanges, safety guard, taper pin, metal pads, etc. When an obstacle hits the safety guard, the taper pin which is locked in locking holes breaks, spring coils initially which are in a compressed state inside the hollow cylinders expands which makes the shaft move forward (along the moving direction of an automobile) to resist the applied load. [ABSTRACT FROM AUTHOR]

Belleville springs are important type of springs. They are frusto-conical in shape. Nowadays, they are extensively used because they occupy less space and support high load with small deflection. Load-deflection characteristics of a Belleville spring can be altered by introducing holes in the springs. In this research work, Finite Element analysis of Belleville spring and experimental investigation using strain gauge was carried out. Finite Element analysis was carried out on a plain spring and results are compared with theoretical analysis. Analysis was also carried out on Belleville spring by introducing holes. It was observed that Load-deflection characteristics can be altered by introducing holes which can be used as an advantage. Experimental investigation was carried out using strain gauges for different configuration of Belleville springs such as plain spring, spring with holes. From the studies it was observed that Theoretical, Finite Elemental and Experimental analyses were in good agreement. When holes were introduced, the magnitude of maximum stress was increased by 20%. Thus, when a slight increase in stress is tolerated, a given load- deflection characteristics can be achieved by using springs with holes. Moreover, Belleville spring and helical spring combination can be used to develop high deflection load cell. [ABSTRACT FROM AUTHOR]

The safety factor of a vehicle is the most important aspect other than its design and comfort. In recent times, most of the automotive manufactures have shown a great amount of interest towards the safety of automobiles as it is directly relevant to the safety of its passengers. Even though many automotive firms come up with many new and improved methods to reduce the rate of accidents, it is still at large. The present work deals with an alternative method that can be used to prevent the major impact on the vehicle during the accident in order to reduce injury to the passengers. In the present- day passenger vehicles bumpers are of hallow section which causes severe damage to the passengers and the vehicle. Hence, to reduce this damage an impact damper has been developed. The present work deals with the design and analysis of an impact damper which is used to reduce the impact, which consists of two concentric helical springs that recerts back the absorbed energy developed during impact. The impact dampers help to prevent accidents and keeps the passengers safely. It also helps to reduce the detrimental cost to a great extent. The analysis has been carried out using LS-DYNA and the results obtained were quite satisfactory. [ABSTRACT FROM AUTHOR]

Highly sensitive application like spring needs some additional care in design. The impact of improvement is very high if its application is high or its significant effects on tangible and intangible benefits. This research identified a part in the automobile clutch system which replaces a massive amount of components from its instantaneous precursor, spring of coil type and clutch cover of lever-type. Such component is none other than helical coil spring of automobile light vehicle Suspension. Its cost is less due to its determined complication in shape and manufacturability. In most cases the mass of the component is the issue in automobile and in particularly such sensitive component of helical coil spring of automobile light vehicle Suspension. Hence here it is focused for material validation. The material validation is main aim of this piece of research. The materials like EN AW – 2011 -3.1655and Wrought Stainless Steel were considered for investigation. The SOLIDWORKS preferred for this study. The helical coil spring of automobile light vehicle Suspension is designed and modeled. The finite element analysis is employed to deploy the material behaviors in the computer aided investigation [ABSTRACT FROM AUTHOR]

Two-phase gas-liquid flow through curved pipes is much more complex in nature than straight pipes due to the existence of secondary flow and phase separation. Experimental investigations have been carried out to evaluate the holdup for gas-non-Newtonian liquid flow through the helical coils in horizontal orientation. In ANN prediction Multilayer Perceptron (MLP) with backpropagation algorithm and four different conventional transfer functions in the hidden layer is used. The ANN prediction agrees well with the experimental data. [ABSTRACT FROM AUTHOR]

The problem of determining the pressure losses in helical coil is important in design and analysis of the fluid machinery. It is well known that when a fluid flows through a curved pipe, the flow pattern becomes more complex than that of a straight pipe because of the generation of secondary flows due to the interaction between centrifugal and viscous forces. To understand the interaction between the two-phase gas- non-Newtonian liquid flow through helical coil tube, hydrodynamic modeling is being performed with a commercial computational fluid dynamics (CFD) code-FLUENT 6.3. The modeling has attempted to describe the results of flow visualization experiments performed in transparent helical coil tube. Both phases are first treated separately as homogeneous. Coupling is achieved through pressure and interphase exchange coefficients. Multiphase model Eulerian-Eulerian, viscous non-Newtonian laminar power law model is used to describe the interaction between the phases. The CFD modeling is compared with the experimental data. [ABSTRACT FROM AUTHOR]

The Large Helical Device (LHD) is the largest heliotron-type super-conducting fusion experimental device. One of the features of the heliotron configuration is its unique edge magnetic field topology. There exist an intrinsic stochastic layer just outside of the last closed flux surface (LCFS), residual islands embedded in the stochastic layer, whisker structures, laminar layers and intrinsic divertor structure (helical divertor). That contrasts to ‘onion-skin’ like magnetic field structure in poloidal divertor tokamaks scrape-off layer (SOL). The edge field line structure can be characterized by Kolmogorov length and field line connection length from wall to the other wall. In the stochastic layer, Kolmogorov length is much longer than connection length. Typical connection length of field lines in the stochastic layer and laminar layers are several kilometers and below several tens of meters, respectively, and these structures co-exist. Therefore, the radial profile of field lines connection length becomes complex contrasting to that in poloidal divertor tokamaks SOL. Plasma transport in the LHD edge region has been studied experimentally by using Langmuir probes and Thomson scattering method, and numerically by using three dimensional plasma and neutral transport codes. In this paper, the physical basis of the heliotron configuration, especially the characteristics of the edge magnetic field topology is presented. Understandings of plasma transport in such a unique magnetic field structure are discussed. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Recent progress of the gyrokinetic-Vlasov simulations on the ion temperature gradient (ITG) turbulence in tokamak and helical systems is reported, where the entropy balance is checked as a reference for the numerical accuracy. The tokamak ITG turbulence simulation carried out on the Earth Simulator clearly captures a nonlinear generation process of zonal flows. The tera-flops and tera-bytes scale simulation is also applied to a helical system with the same poloidal and toroidal periodicities of L = 2 and M = 10 as in the Large Helical Device. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

This work is divided into two different lines of research. The first one is devoted to the gyrokinetic simulations of ITG linear instabilities and ZF-GAM damping in multiple-helicity magnetic field configurations. The multiple helicity terms are required to study inward-shifted scenarios in LHD and are responsible for the improvement of the neoclassical helical ripple transport. It is thought that they also enhance the residual ZF in these inward shifted scenarios, thus reducing also the anomalous transport. These studies are to be the starting point of full non-linear simulations. In the second part, numerical simulations of Electron Bernstein Waves (EBW) are performed in order to justify the experimentally observed increase of the stored energy in the Compact Helical System (CHS) in NIFS, when EC waves are launched into a comparatively over-dense plasma. Calculations of ray-tracing, mode-conversion and power deposition of OXB converted waves are presented. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]