A COMPUTATIONAL APPROACH FOR EVALUATING HELICAL COMPRESSION SPRINGS
Helical compression springs are generally synthesized and evaluated by determining the maximum torsional stress, fatigue life, natural frequency, and/or load loss due to stress relaxation. To this end, researchers have developed finite element analysis (FEA) modeling methods to simulate the design performance of helical compression springs. The intent of this paper was to make a useful contribution to the published works for evaluating round wire helical compression springs. Specifically, commercially available FEA software was used to construct a structural model of a helical compression spring to simulate its full range of compression. The proposed FEA modeling methodology considers coil-to-coil contact and the end coils were modeled as rigid surfaces. With 9 mm of compression, the predicted spring rate correlated with the analytically calculated value to within 5%.
TECHNOLOGY Analysis of the Design of Helical Compression Spring to Study the Behaviour of Steel and Composites Used as Spring Materials
Presently the automobile manufacturers are facing challenges of improvements in the quality and performance of the components together with the reduction in weight and cost of manufacturing. Efforts are directed towards the use of alternative materials in design which results in increase of strength to weight ratio. The use of composite materials is increasing in the design of automobile components due to their light weight and costs. The present work attempts to study the feasibility of select composite materials in the design of helical compression spring used in automobile suspension systems. The design of helical compression spring is first analysed for the conventional steel material (IS 4454 Grade 3) and then compared with that of for the composites used as spring materials study their behaviours at the two loading conditions of 1500N(normal loads) and 3000N (overload). Composite materials considered for the present study are Eglasss/Epoxy and Carbon/Epoxy. The modeling of the helical spring has been done using CREO 2.0 and simulation were performed using ANSYS v 14.5 to predict the stresses, deflections and strain energies at the stated loads. It was observed that the stresses developed in composite material helical compression spring is lower as compared to the stresses developed in conventional steel (IS 4454 Grade 3)helical compression spring. Also the deflection and strain energies are observed to be higher for composite materials. The results indicate that composite materials are feasible option at normal loading conditions which will also reduce the manufacturing and maintenance costs
Heavy metal adsorption from industrial wastewater by PAMAM/TiO2 nanohybrid: Preparation, characterization and adsorption studies
Abstract This study investigates the removal of heavy metals from industrial wastewater using TiO 2 nanoparticles modified with poly-amidoamine dendrimer (PAMAM, G 4 ). The metal ions Cu 2 + , Pb 2 + , and Cd 2 + were selected as model pollutants. FTIR, SEM, BET surface area and Zeta potential measurements, and Dispersion Observing methods have been employed for characterizing the synthetic nanohybrid and these techniques indicated that the PAMAM loaded on to TiO 2 have been favorably synthesized. The effects of several parameters including initial metal ion concentration, temperature, pH solution, the nanohybrid dosage and contact time were studied. The experimental data were analyzed using equilibrium isotherm and kinetics models. The adsorption process was studied using isotherm, kinetics, and thermodynamics models. The analysis shows that the Langmuir isotherm and pseudo-second-order kinetics are appropriate models for the adsorption process. The thermodynamic parameters illustrate that the absorption is endothermic and spontaneous. The findings suggest that the nanohybrid is a good super absorbent for the removal of heavy metals from industrial effluents.