Method Of Final Elements Research Articles

Numerical modeling of the stress-strain behavior of a viscoelastic material in a 2D model by FEM

Numerical modeling of behavior plays an important role in knowing the changes to be made and in optimizing simulation results. Currently, modeling occupies a very necessary place in modern industry for the life study of any problem. This paper deals numerically with the variation and relationship between stress and strain for a model of tensile behavior. In addition, the study is based on the one hand on the number of holes in a plate, and on the other hand by the increase in the tensile load 10, 20 and 30N. The FEM finite element method was used. Additionally, the viscoelastic material was applied. In addition, the parametric mesh has square elements of type (CPS4) bilinear plane stress quadrilaterals, with 4 nodes were used. However, can contribute to a better understanding of the problem of guiding by different numbers of holes concerning viscoelastic behavior for an epoxy material. In addition, this study allows us to know which model is the most resistant during tightening. The results of the final element method (FEM) numerical model were compared, after application of different loadings, to determine the deformation and stress resulting from these loadings, particularly at the holes. On the other hand, the study showed that there is a relationship between viscosity and stress, and a relationship between deformation and stress according to Hooke's law. The variation and the relationship between the stress-strain is then modeled using the finite element calculation code ABAQUS. In addition, the results obtained concerning the numerical simulation were compared and discussed between the different case studies. A good correspondence was obtained between the different comparison results in all the modeling cases of our work.

К вопросу о расчете продольных колебаний коленчатого вала поршневых двигателей

One of the initial stages of calculating the crankshaft longitudinal vibrations is developing an oscillatory system model, which includes the determination of longitudinal pliability (rigidity) of elastic sections. If it is impossible to determine the pliability experimental, the empiric formulas or the final element method (FEM) are used. There are given the values of crank longitudinal pliability of the crankshafts of different marine engine types found by using the formulas of L. Gugliemotti – R. Machciotta, P. Draminsky, E. Y. Gorbunov, S. F. Dorey, N. S. Skorchev, V. S. Stoyanov, etc. It is shown that the calculation results obtained from these formulas for the same engine significantly differ; therefore, the choice of one or another empirical formula for practical calculations is difficult. The preference of using FEM for determining the longitudinal (axial) compliance of cranks and other areas with complex geometric shapes has been proven. The possibility of its application is also shown to determine the longitudinal disturbing force as the reaction of the crankshaft support against the action of the radial force exerted to the connecting rod journal. It is proposed to use, along with empirical formulas, regression equations connecting the longitudinal compliance of the cranks with a significantly larger number of their design dimensions.

Evolution of deformation texture in cold drawing of steel tubes using EBSD analysis and FEM simulation

Cold drawing of steel tubes is the manufacturing process characterized by anisotropic material flow during drawing. In this paper, the micro structural of the E235 steel tube after recrystallization annealing and cold drawing were characterized by optical microscopy and EBSD (Electron BackScatter Diffraction) analysis performed on a scanning electron microscope. The input feedstock after recrystallization annealing with dimensions of ø 25.0 mm × 1.5 mm (O.D × W.T.) was cold drawn in two drawing passes with fixed plug to the final dimensions of ø 18.0 mm × 0.9 mm (O.D × W.T.). The development of crystallographic texture (both qualitative and quantitative) was analysed on a longitudinal section of the tube. The stress-strain state in the tube material during drawing was calculated by FEM (Final Element Method) software and the development of the texture depending on the stress-strain state in three different directions using cylindrical coordinates with respect to the drawing direction was evaluated. We have investigated the ratio of individual crystallographic planes depending on stress state during drawn tube. The main objective was to define the development of crystallographic grain orientation from stress-strain state during cold drawn tube.

Solid Modeling and Dynamic Analysis of Mechanisms of Press-forging Machines

Based on the example of AV1818 machine for cold die forging the paper considers the matters of complex use of solid modeling systems (Autodesk Inventor Professional) and the dynamic analysis of mechanisms (DAM) to solve problems associated with the performance forecasting of forge-and-pressing equipment at the stage of their design. The dynamic processes in the mechanisms, primarily, the dynamic forces and positioning accuracy of units are defined based on the models representing systems of point masses connected with elastic ties. Basic parameter computation for the objects of models (units of mechanisms or their fragments): inertia (mass or inertia moment) and elasticity (rigidity at strain-compression, bend or torsion) is a rather complicated task solved with the methods of theoretical mechanics and resistance of materials. The procedure suggested in the work allows increasing the accuracy of calculations and decreasing their complexity at the expense of the final element method (FEM) to solid models of these objects.

An investigation on the influence of rotor geometry on axial forces in the magnetoelectric damper of a suspension system

The magnetoelectric-damper geometry and influence of mechanical parameters onthe axial forces and on the electromagnetic processes in the damper are investigated. An analytic method for determining the magnetoelectric-damper axial forces is developed, and bases are given for a rotor with projections designed for minimizing axial forces is proved. Magneto electric-damper three-dimensional computer modeling using the final-elements method was carried out to confirm the theoretical data.

Thermal Properties Improving of the Electromotor Frame

The contribution presents the cooling rib optimization on the two numerical models with the aim to show the influence of used model symmetry geometry on the design optimization problem properties. The parameters of used computational models (the models differ in used symmetry conditions) and the application of boundary conditions are presented. The optimization is based on FEM (Final Elements Method) structural thermal analysis and is done by ANSYS Workbench v11 software package. The obtained results show the necessity to take into account the authentic rib space arrangement in model simulations of optimization problem.