scholarly journals The Nonlinear Dynamic Behavior Analysis and Research for Sheet Steel Stamping Forming Problems Based on Finite Element Method

2015 ◽  
Vol 9 (1) ◽  
pp. 198-202
Author(s):  
Li Zhang ◽  
Tao Zhang ◽  
Kaiteng Wu
Keyword(s):  
Finite Element ◽  
Initial Conditions ◽  
Equations Of Motion ◽  
Sheet Steel ◽  
Element Model ◽  
Stress Strain ◽  
Contact Conditions ◽  
Deformation Stages ◽  
Element Algorithm ◽  
The Finite Element Model

A numerical framework for the simulation of sheet steel stamping forming is presented. The main problems, the equations of motion, the constitutive relation, the initial conditions, boundary conditions and contact conditions, are presented in detail. Based on this, the finite element model is established and solved for exploring the changes in laws of stress, strain and so on. The information on stress, strain and load displacement is obtained at different deformation stages. The numerical results show that the finite element algorithm can effectively simulate the deformation process of sheet steel which helps to explain that the numerical framework is feasible for sheet steel stamping forming problems.

scholarly journals Linear Vibration Analysis of Shells Using a Seven-Parameter Spectral/hp Finite Element Model

2020 ◽  
Vol 10 (15) ◽  
pp. 5102
Author(s):  
Carlos Valencia Murillo ◽  
Miguel Gutierrez Rivera ◽  
Junuthula N. Reddy
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Variable Thickness ◽  
Equations Of Motion ◽  
Shear Deformation Theory ◽  
Element Model ◽  
Linear Elastic ◽  
Commercial Code ◽  
The Finite Element Model ◽  
Hp Finite Element

In this paper, a seven-parameter spectral/hp finite element model to obtain natural frequencies in shell type structures is presented. This model accounts for constant and variable thickness of shell structures. The finite element model is based on a Higher-order Shear Deformation Theory, and the equations of motion are obtained by means of Hamilton’s principle. Analysis is performed for isotropic linear elastic shells. A validation of the formulation is made by comparing the present results with those reported in the literature and with simulations in the commercial code ANSYS. Finally, results for shell like structures with variable thickness are presented, and their behavior for different ratios r/h and L/r is studied.

A Parallel h-Adaptive Finite Element Model for Wind Energy Assessment in Nevada

2003 ◽  
Author(s):  
Darrell W. Pepper ◽  
Yitung Chen ◽  
Joseph M. Lombardo
Keyword(s):  
Finite Element ◽  
Wind Energy ◽  
Finite Element Model ◽  
Initial Conditions ◽  
Meteorological Data ◽  
Equations Of Motion ◽  
Element Model ◽  
Adaptive Finite Element ◽  
Galerkin Finite Element ◽  
Energy Assessment

A Petrov-Galerkin finite element model that employs local mesh adaptation is being developed to determine potential wind energy sites within the state of Nevada. Meteorological data collected from various private, county, city, and government agencies are used to generate diagnostic flow fields, which subsequently provide initial conditions for the prognostic solution of the time-dependent equations of motion and species transport. The model runs on a multiprocessor SGI Onyx 3800. Results of the data collection, including wind energy site forecasts, will be made available on the web when the assessment for the entire state is completed.

scholarly journals ANALYSIS OF FEATURES OF APPLIED SOFTWARE “LIRA” IN CALCULATIONS OF NON-CIRCULAR TUNNEL LININGS

2019 ◽  
pp. 41-50
Author(s):  
V. P. KUPRIY ◽  
O. L. TIUTKIN ◽  
P. YE. ZAKHARCHENKO
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Software Package ◽  
Strain State ◽  
Element Model ◽  
Finite Element Models ◽  
Stress Strain ◽  
Stress Strain State ◽  
The Finite Element Model

Purpose. The article examines the effect on the stress-strain state of the parameters of the finite-element model created in the “Lira” software package in a numerical analysis of non-circular outlined tunnels. Methodology To achieve this goal, the authors developed finite element models of the calotte part of the mine during the construction of a double track railway tunnel using “Lira” software. In each of the models in the “Lira” software package, the interaction zone with temporary fastening was sampled in a specific way. After creation of models, their numerical analysis with the detailed research of his results was conducted. Findings. In the finite element models, the values of deformations and stresses in the horizontal and vertical axes, as well as the maximum values of the moments and longitudinal forces in the temporary fastening were obtained. A comparative analysis of the obtained values of the components of the stress-strain state with a change in the parameters of the finite element model was carried out. The graphs of the laws of these results from the discretization features of the two models were plotted. The third finite element model with a radial meshing in the zone of interaction of temporary support with the surrounding soil massif was investigated. Originality It has been established that in the numerical analysis of the SSS of a tunnel lining of a non-circular outline, its results substantially depend on the shape, size and configuration of the applied finite elements, on the size of the computational area of the soil massif, and also on the conditions for taking into account the actual (elastic or plastic) behavior of the soil massif.  Practical value. The features of discretization and the required dimensions of the computational area of the soil massif were determined when modeling the “lining – soil massif” system, which provide sufficient accuracy for calculating the parameters of the stress-strain state of the lining.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

Redrawing Operation a Star Shape from Cylindrical Shape Using Experimental and FE Analysis

2020 ◽  
Vol 38 (1A) ◽  
pp. 25-32
Author(s):  
Waleed Kh. Jawad ◽  
Ali T. Ikal
Keyword(s):  
Finite Element ◽  
Effective Strain ◽  
Element Model ◽  
Cylindrical Shape ◽  
Element Analysis ◽  
Punch Force ◽  
Maximum Value ◽  
Element Simulation ◽  
Blank Sheet ◽  
The Finite Element Model

The aim of this paper is to design and fabricate a star die and a cylindrical die to produce a star shape by redrawing the cylindrical shape and comparing it to the conventional method of producing a star cup drawn from the circular blank sheet using experimental (EXP) and finite element simulation (FES). The redrawing and drawing process was done to produce a star cup with the dimension of (41.5 × 34.69mm), and (30 mm). The finite element model is performed via mechanical APDL ANSYS18.0 to modulate the redrawing and drawing operation. The results of finite element analysis were compared with the experimental results and it is found that the maximum punch force (39.12KN) recorded with the production of a star shape drawn from the circular blank sheet when comparing the punch force (32.33 KN) recorded when redrawing the cylindrical shape into a star shape. This is due to the exposure of the cup produced drawn from the blank to the highest tensile stress. The highest value of the effective stress (709MPa) and effective strain (0.751) recorded with the star shape drawn from a circular blank sheet. The maximum value of lamination (8.707%) is recorded at the cup curling (the concave area) with the first method compared to the maximum value of lamination (5.822%) recorded at the cup curling (the concave area) with the second method because of this exposure to the highest concentration of stresses. The best distribution of thickness, strains, and stresses when producing a star shape by

Analysis of Hydroelectric Unit’s Upper Bracket Based on Test and FEM

2014 ◽  
Vol 721 ◽  
pp. 131-134
Author(s):  
Mi Mi Xia ◽  
Yong Gang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Element Model ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Element Analysis ◽  
Hydroelectric Unit ◽  
The Finite Element Analysis ◽  
Strain Rosette ◽  
The Finite Element Model

To research the load upper bracket of Francis hydroelectric unit, then established the finite-element model, and analyzed the structure stress of 7 operating condition points with the ANSYS software. By the strain rosette test, acquired the data of stress-strain in the area of stress concentration of the upper bracket. The inaccuracy was considered below 5% by analyzing the contradistinction between the finite-element analysis and the test, and match the engineering precision and the test was reliable. The finite-element method could be used to judge the stress of the upper bracket, and it could provide reference for the Structural optimization and improvement too.

Analysis of Premium Connection of Connecting and Sealing Ability Loaded by Axial Tensile Loads

2012 ◽  
Vol 268-270 ◽  
pp. 737-740
Author(s):  
Yang Yu ◽  
Yi Hua Dou ◽  
Fu Xiang Zhang ◽  
Xiang Tong Yang
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Tensile Load ◽  
Element Model ◽  
Sealing Ability ◽  
Axial Tensile ◽  
High Level ◽  
Maximum Contact ◽  
Contact Pressures ◽  
The Finite Element Model

It is necessary to know the connecting and sealing ability of premium connection for appropriate choices of different working conditions. By finite element method, the finite element model of premium connection is established and the stresses of seal section, shoulder zone and thread surface of tubing by axial tensile loads are analyzed. The results show that shoulder zone is subject to most axial stresses at made-up state, which will make distribution of stresses on thread reasonable. With the increase of axial tensile loads, stresses of thread on both ends increase and on seal section and shoulder zone slightly change. The maximum stress on some thread exceed the yield limit of material when axial tensile loads exceed 400KN. Limited axial tensile loads sharply influence the contact pressures on shoulder zone while slightly on seal section. Although the maximum contact pressure on shoulder zone drop to 0 when the axial tensile load is 600KN, the maximum contact pressure on seal section will keep on a high level.

The structural optimization of roadheader conical picks based on fatigue life

2018 ◽  
Vol 09 (02) ◽  
pp. 1850013 ◽  
Author(s):  
Zhenguo Lu ◽  
Lirong Wan ◽  
Qingliang Zeng ◽  
Xin Zhang ◽  
Kuidong Gao
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Static Analysis ◽  
Element Model ◽  
Cutting Resistance ◽  
Strength Failure ◽  
New Type ◽  
Conical Picks ◽  
Fatigue Life Analysis ◽  
The Finite Element Model

Conical picks are the key cutting components used on roadheaders, and they are replaced frequently because of the bad working conditions. Picks did not meet the fatigue life when they were damaged by abrasion, so the pick fatigue life and strength are excessive. In the paper, in order to reduce the abrasion and save the materials, structure optimization was carried out. For static analysis and fatigue life prediction, the simulation program was proposed based on mathematical models to obtain the cutting resistance. Furthermore, the finite element models for static analysis and fatigue life analysis were proposed. The results indicated that fatigue life damage and strength failure of the cutting pick would never happen. Subsequently, the initial optimization model and the finite element model of picks were developed. According to the optimized results, a new type of pick was developed based on the working and installing conditions of the traditional pick. Finally, the previous analysis methods used for traditional methods were carried out again for the new type picks. The results show that new type of pick can satisfy the strength and fatigue life requirements.

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