Papers by Keyword: Elastomers

Abstract: The relevance of the use of elastic polymers (elastomers) in the structure of vehicle suspension is ensured by reducing the metal content, the unsprung mass and the overall dimensions of the elastic and damping suspension elements, and by increasing ride comfort and resistance to external factors. The aim of the study is to substantiate, theoretically and practically, the advantages of using elastomeric materials in terms of the quality of ride and the increase of the elastic and damping elements power intensity in comparison with standard designs. The comparative analysis of the parameters of standard structures and alternative ones allows us to make a conclusion the advantages of using elastomers in terms of increasing the power intensity of the elastic-damping suspension structure, reducing the values of the unsprung masses.

Abstract: In order to find hyperelastic material model constants, data fitting technique is often used. For this task, the data is collected through different laboratory tests, namely, the uniaxial, the biaxial and the pure shear. However, due to the difficulty in getting biaxial data, often only uniaxial data was used for the fitting. Despite frequent use, it was established that this practice creates erroneous results. With a view to improve the data fitting results and at the same time to overcome the difficulty of collecting primary biaxial data, uniaxial data was used to generate a secondary biaxial data set. The data derived through this method was then tested with four common models as to examine the compatibility of the method. Subsequently, real biaxial data was used to compare with the data fitting results obtained through the proposed method. As results indicated combined data fitting for both instances were very much identical with respect to all tested models. Cases where somewhat higher deviation observed between experimental curves and data fitted curves for biaxial data, gave similar results for adjusted data driven data fitting too. However, such deviation could be attributed to mismatch between models with the particular material behaviour rather than the generated data.

Abstract: Stiff coating on the phase-separated soft polyurethane substrate under the compression deformation is investigated by the finite element modeling (FEM). External strain leads to the wrinkling of layer surface, which is characterized by a set of wavelengths and amplitudes. The influence of the thickness and stiffness of the layer, elastic modulus of the substrate on the structural-mechanical properties of the deformed surface is studied. The results of the model are in good accordance with the experiment (plasma immersion ion impanation of nitrogen ions into the polyurethane substrate) and allowed to estimate the modulus of the coating and the deformation of the surface.

Abstract: In this study, the tube material for Self-Inflating Tire was synthesized. A few suitable materials for the tube material compounding process were identified through a literature review. Using the material properties of this tube, CAE modeling was done for analysis. The ANSYS Fluid Structure Interaction (FSI) method was then used to consider the internal flow with the structure. In addition, a machine was prepared for testing the performance of the tube. The results of the CAE analysis were compared with results of the testing machine. The developed equipment and systems can be used for the manufacture of high-performance and safe tires. Finally, the prototype of the tube was prepared and fitted in a tire, and the driving performance of the vehicle tested. Using this test result, compatibility of the tube's material has been confirmed.

Abstract: We study the effects of two scaling exponents on the mechanical properties of swollen elastomers under equibiaxial and planar extensions. Two scaling exponents are introduced to extend the Flory-Rehner free energy function, and are adjusted based on the previous study. Results show that swelling-induced strain softening is apt to occur under equibiaxial extension compared to uniaxial extension. The additional tensile stress in a lateral direction enables it to occur in relatively poor solvents, and accelerates the onset point. Planar extension shows more complicated responses because the stress in the constrained direction changes dramatically depending on the combination of two scaling exponents and the Flory-Huggins interaction parameter.

Abstract: The present study aims to investigate the impact of biodiesel-diesel-bioethanol (BDE) blended fuel on the degradation behavior of elastomers such as nitrile rubber (NBR) and polytetrafluroethylene (PTFE). Static immersion test in B20D75E5 blends (20% biodiesel, 75% diesel and 5% bioethanol) at 50°C for 200 h was carried out. At the end of immersion test, degradation behaviour of elastomers was investigated by measuring mass, volume and hardness. The exposed surface of elastomers was studied using optical microscope (OM). Fourier Transform Infrared (FTIR) spectroscopy was carried out to identify the chemical and structural changes in the elastomers. Moreover, physical and chemical characteristics of the fuel blend after the immersion test such as total acid number (TAN), density and colour change were also investigated. Results showed that the degradation of NBR was high compared to PTFE.

Abstract: The work considers using a multilayer elastomeric package for the vibroisolation of engineering constructions under the action of periodic vibration. The multilayer elastomeric package is located between the protected object and a vibrating base; it consists of alternating thin metallic and elastomeric layers jointed by vulcanization or gluing. The paper discusses flat rubber-metal elements of circular shapes with reinforcing steel layers and describes kinematic excitation directed flatwise. The analytical expression of the characteristics of the compression stiffness of the plane multilayered elastomeric structure is derived on the basis of the variational principle, and metallic plates-layers are assumed to be perfectly rigid. An analytical solution was confirmed by experimental data. The fitted equation for “force-displacement” was derived and used in the equation of motion on of the protected object.