scholarly journals Evaluation of Normal Pressures during Filling in Steel Hoppers with Eccentric Outlet

2020 ◽  
Vol 9 (3) ◽  
pp. 138-149
Author(s):  
Alireza Moazezi Mehretehran ◽  
Shervin Maleki
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Physical Space ◽  
Industrial Applications ◽  
Filling Process ◽  
Material Parameters ◽  
Starting Point ◽  
Shallow Side ◽  
Two Parameters ◽  
Complicated Geometries

Filling pressures are a necessary starting point in the design of silos and hoppers. The hoppers with complicated geometries are common in industrial applications due to physical space constraints and the need to interface with other processing equipment. The current paper deals with the effect of outlet eccentricity on normal pressures formed in steel hoppers during distributed filling process. Using finite element method, progressive filling process in hoppers was simulated and by changing the percentage of outlet eccentricity, the variation of pressure distribution was fully studied. The results showed an increase in the normal pressures of shallow side compared with the steep side of eccentric hopper. To quantify the pressure asymmetry, two parameters were introduced and they were evaluated for practical range of material parameters and steel hoppers dimensions. The results obtained are of interest since they facilitate the design of silos and hoppers with eccentric outlet.

A Model for the Prediction of Form Errors in Face Milling and Turning

1999 ◽  
Author(s):  
Luc Masset ◽  
Jean-François Debongnie ◽  
Sylvie Foreau ◽  
Thierry Dumont
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cutting Forces ◽  
Experimental Validation ◽  
Industrial Applications ◽  
Face Milling ◽  
The Finite Element Method ◽  
Form Errors ◽  
Error Computation ◽  
Element Method

Abstract A method is proposed for predicting form errors due to both clamping and cutting forces in face milling and turning. It allows complex tool trajectories and workpiece geometries. Error computation is performed by the finite element method. An experimental validation of the model for face milling is presented. Two industrial applications are produced in order to demonstrate the capabilities of the method.

Natural frequencies of a rotating curved cantilever beam: A perturbation method-based approach

2020 ◽  
Vol 234 (9) ◽  
pp. 1706-1719
Author(s):  
Ajinkya Baxy ◽  
Abhijit Sarkar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Perturbation Method ◽  
Cantilever Beam ◽  
Natural Frequencies ◽  
Analytical Formula ◽  
Industrial Applications ◽  
Curved Beam ◽  
Straight Beam ◽  
Element Method

The blades of propellers, fans, compressor and turbines can be modeled as curved beams. In general, for industrial application, finite element method is employed to determine the modal characteristics of these structures. In the present work, a novel formula for determining the natural frequencies of a rotating circularly curved cantilever beam is derived. Rayleigh–Ritz approach is used along with perturbation method to obtain the analytical formula. In the first part of the work, a formula for natural frequencies of a non-rotating curved beam vibrating in its plane of curvature is presented. This formula is derived as a correction to the natural frequencies of its straight counterpart. The curvature is treated as a perturbation parameter. In the next part of the work, the effect of rotation on the curved beam is captured as an additional perturbation. Thus, the formula for a curved rotating beam is derived as a correction (involving two perturbation parameters) to the non-rotating straight beam. The results obtained using the derived formula are compared with the finite element method results. It is found that the frequency estimates from the formula are valid over a fairly large range of curvature and rotation speed. Thus, the derived formula can provide a faster alternative for design iterations in industrial applications.

Variational multi-scale finite element method for the two-phase flow of polymer melt filling process

2019 ◽  
Vol 30 (3) ◽  
pp. 1407-1426 ◽  
Author(s):  
Xuejuan Li ◽  
Ji-Huan He
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Method ◽  
Two Phase Flow ◽  
Polymer Melt ◽  
Phase Flow ◽  
Filling Process ◽  
Two Phase ◽  
Content Type ◽  
Element Method

Purpose The purpose of this paper is to develop an effective numerical algorithm for a gas-melt two-phase flow and use it to simulate a polymer melt filling process. Moreover, the suggested algorithm can deal with the moving interface and discontinuities of unknowns across the interface. Design/methodology/approach The algebraic sub-grid scales-variational multi-scale (ASGS-VMS) finite element method is used to solve the polymer melt filling process. Meanwhile, the time is discretized using the Crank–Nicolson-based split fractional step algorithm to reduce the computational time. The improved level set method is used to capture the melt front interface, and the related equations are discretized by the second-order Taylor–Galerkin scheme in space and the third-order total variation diminishing Runge–Kutta scheme in time. Findings The numerical method is validated by the benchmark problem. Moreover, the viscoelastic polymer melt filling process is investigated in a rectangular cavity. The front interface, pressure field and flow-induced stresses of polymer melt during the filling process are predicted. Overall, this paper presents a VMS method for polymer injection molding. The present numerical method is extremely suitable for two free surface problems. Originality/value For the first time ever, the ASGS-VMS finite element method is performed for the two-phase flow of polymer melt filling process, and an effective numerical method is designed to catch the moving surface.

A Contribution to the Optimisation of a Simple Shear Test

2009 ◽  
Vol 410-411 ◽  
pp. 467-472 ◽  
Author(s):  
Marion Merklein ◽  
M. Biasutti
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Shear Test ◽  
The Finite Element Method ◽  
Simple Shear Test ◽  
Material Parameters

The finite element method is a widely used tool in sheet metal forming. The quality of the results of such an analysis depends largely on the applied constitutive model and its material parameters, which have to be determined experimentally. These data are relevant on the choice of the yield criterion among the wide range of options available in the commercial applications implementing the finite element method. Since the accuracy of material parameters estimation is therefore crucial, investigations were performed with an Al-Mg sheet alloy and a mild steel sheet to optimize a Miyauchi-based simple shear test. This method is one of the basic ways to investigate the plastic properties of a sheet metal up to large strains, which is very important for numerical analysis of sheet metal forming processes. Aim of the test is to determine the shear stress-strain correlation. In order to enhance the quality of the experimental results the detection of the deformation’s field, trough an optical measurement system, and the methodology for its evaluation are focus of the present study.

Coupling Finite Element Method and Perturbation Techniques for Non Linear Vibrations of Plates

1999 ◽  
Author(s):  
L. Azrar ◽  
R. Benamar ◽  
M. Potier-Ferry
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computation Time ◽  
Free Vibrations ◽  
Perturbation Techniques ◽  
Structural Problems ◽  
Starting Point ◽  
Linear Vibrations ◽  
The Right ◽  
Element Method

Abstract The effectiveness of the coupling of the perturbation techniques and the finite element method has been demonstrated using a method called Asymptotic-Numerical Method (ANM). This concept eliminates the major difficulties of the classical perturbation methods namely the complexity of the right hand sides and the limitation of the validity of the solution obtained. In this paper we present the development of this method and its applicability for large amplitudes free vibrations of plates. The displacement and the frequency are expanded into power series with respect to a control parameter. The nonlinear governing equation is transformed into a sequence of linear problems having the same stiffness matrix. Needing one matrix inversion, a large number of terms can be computed with a small computation time. Taking the starting point in the zone of validity, the method is reapplied in order to determine a further part of the nonlinear solution. In order to increase the zone of validity, the Pade approximants are incorporated. Iterations of this method lead to a powerful incremental method. Numerical tests for large amplitudes free vibrations of plates with various shapes and boundary conditions are reported. Recent improvements in the basic ANM algorithm as well as applications to various structural problems are added in order to exhibit the effectiveness and the applicability of this method.

A novel mapping finite element method for stress analysis in two dimensions

1981 ◽  
Vol 16 (3) ◽  
pp. 149-157 ◽  
Author(s):  
B Nath ◽  
P Nath
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Physical Space ◽  
Two Dimensions ◽  
Physical Domain ◽  
Problem Domain ◽  
Image Domain ◽  
Type Mapping ◽  
Polar Type ◽  
Element Method

A mapping finite element method has been proposed in this paper for the solution of elasto-static problems in two dimensions. In this method the physical problem domain is mapped into an ‘image’ domain using exponential-polar type mapping functions. Properties of finite elements in the image domain are also obtained in accordance with the transformation implemented; these elements are then used to solve the problem in the image domain, subject to the appropriately transformed boundary conditions. Results of examples considered show that the proposed method, which is, incidentally, no more difficult or cumbersome to implement than the standard FEM, gives significantly better accuracy than when the standard FEM is used to solve the problem in the physical domain, using the same number of equations. Furthermore, since physical space is logarithmically condensed into the image space, the method is capable of dealing with large aspect ratio problems more simply and economically than is possible with the standard FEM or the boundary element method.

Sign in / Sign up

Export Citation Format

Share Document