scholarly journals CALCULATION OF CONTROLLED TIGHTENING EFFORT IN GROUP BOLTED JOINT

2020 ◽  
Vol 2020 (6) ◽  
pp. 12-21
Author(s):  
Ruslan Guchinskiy
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Reliable Estimate ◽  
Load Factor ◽  
Geometrical Parameters ◽  
Standard Group ◽  
Bolted Joint ◽  
Operation Conditions ◽  
First Time ◽  
Element Method

The optimum value choice of a tightening effort is significant for assurance of a reliable operation of a group bolted joint. A work goal consists in the calculation and comparison of essential conditions of tightening efforts for a bolted joint of a bracket and a plate with analytical and numerical methods. For the first time it is obtained that the use of tightening factors recommended in literature by the condition of joint density may fail to ensure its non-disclosure. It is shown that a basic load factor for a bolt of a group joint depends not only upon bolt and flanges yielding, but upon loading and geometrical parameters of a joint. Basic loading factors obtained through a finite element method for a group bolted joint proved to be below ones defined analytically. The use of the procedure for bolt calculations on the basis of the assurance of joint complete non-disclosure results in increased values of tightening efforts caused by non-uniformity of contact stress distribution in flanges because of tightening. There is specified a field of application of the calculation procedure on joint non-disclosure – group joints with high stiffness flanges. At preliminary estimate the efforts for tightening a standard group joint a procedure of joint non-disclosure with the increased tightening factor and a condition of shift absence is recommended for use. To obtain a reliable estimate of the required tightening effort after its preliminary selection it is recommended to check up operation conditions of a group bolted joint with the aid of the calculation through the finite element method.

scholarly journals Combined Semianalytical and Numerical Static Plate Analysis. Part 2: Resultant Multipoint Boundary Problem

2018 ◽  
Vol 196 ◽  
pp. 01011
Author(s):  
Oleg Negrozov ◽  
Pavel Akimov ◽  
Marina Mozgaleva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Problem ◽  
Thin Plates ◽  
Geometrical Parameters ◽  
Element Mesh ◽  
Multipoint Boundary ◽  
Basic Dimension ◽  
Plate Analysis ◽  
Element Method

The distinctive paper is devoted to solution of multipoint boundary problem of plate analysis (Kirchhoff model) based on combined application of finite element method (FEM) and discrete-continual finite element method (DCFEM). As is known the Kirchhoff-Love theory of plates is a two-dimensional mathematical model that is normally used to determine the stresses and deformations in thin plates subjected to forces and moments. The given domain, occupied by considering structure, is embordered by extended one. The field of application of DCFEM comprises fragments of structure (subdomains) with regular (constant or piecewise constant) physical and geometrical parameters in some dimension (“basic” dimension). DCFEM presupposes finite element mesh approximation for non-basic dimension of extended domain while in the basic dimension problem remains continual. FEM is used for approximation of all other subdomains (it is convenient to solve plate bending problems in terms of displacements). Coupled multilevel approximation model for extended domain and resultant multipoint boundary problem are constructed. Brief information about software systems and verification samples are presented as well.

Development of SFEM-Pre: A Novel Preprocessor for Model Creation for the Smoothed Finite Element Method

2019 ◽  
Vol 17 (02) ◽  
pp. 1845002 ◽  
Author(s):  
J. F. Zhang ◽  
R. P. Niu ◽  
Y. F. Zhang ◽  
C. Q. Wang ◽  
M. Li ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Complex Geometry ◽  
Three Dimensional ◽  
Efficient Computation ◽  
Practical Engineering ◽  
Smoothed Finite Element Method ◽  
2D And 3D ◽  
First Time ◽  
Element Method

Smoothed finite element method (S-FEM) is a new general numerical method which has been applied to solve various practical engineering problems. It combines standard finite element method (FEM) and meshfree techniques based on the weaken-weak (W2) formulation. This project, for the first time, develops a preprocessor software package SFEM-Pre for creating types of two-dimensional (2D) and three-dimensional (3D) S-FEM models following strictly the S-FEM theory. Because the software architecture of our 3D processor is the same as our 2D preprocessor, we will mainly introduce the 2D preprocessor in terms of software design for easier description, but the examples will include both 2D and 3D cases to fully demonstrate and validate the whole preprocessor of S-FEM. Our 2D preprocessor package is equipped with a graphical user interface (GUI) for easy use, and with a connectivity database for efficient computation. Schemes are developed for not only automatically meshes the problem domains using our GUI, but also accepts various geometry files made available from some existing commercial software packages, such as ABAQUS®and HyperMesh®. In order to improve the efficiency of our preprocessor, a parallel triangulation mesh generator has also been developed based on the advancing front technique (AFT) to create triangular meshes for complex geometry, and at the same time to create six types of connectivity needed for various S-FEM models. In addition, a database is implemented in our code to record all these connectivity to avoid duplicated calculation. Finally, intensive numerical experiments are conducted to validate the efficiency, accuracy and stability of our preprocessor codes. It is shown that with our preprocessor, an S-FEM can be created automatically without much human intervention for geometry of arbitrary complexity.

The modified characteristics finite element method for time-dependent Darcy-Brinkman problem

2018 ◽  
Vol 36 (1) ◽  
pp. 356-376 ◽  
Author(s):  
Cheng Liao ◽  
Pengzhan Huang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Double Diffusion ◽  
Diffusion Problem ◽  
Content Type ◽  
Characteristics Method ◽  
Complicated Model ◽  
Velocity Pressure ◽  
First Time ◽  
Element Method

Purpose This study aims to capture the effective behavior of double-diffusion problem, which arises from the combined heat and mass transfer in porous medium and develop the modified characteristics finite element method. Design/methodology/approach The proposed finite element method deals with the nonlinear term temporal term by modified characteristics method. Then, the authors compute the velocity, pressure, temperature and concentration using the decoupled technique. Finally, to show the efficiency of the method, the authors give some numerical examples. Findings From the numerical results, one can see that the method has a good accuracy, which shows that the method can simulate this Darcy–Brinkman problem well. Originality/value The originality lies in the fact that the proposed scheme is the first time for solving the Darcy–Brinkman problem, which is a more complicated model, and includes the velocity, pressure, temperature and concentration.

scholarly journals Comprehensive Optimization of the Tripolar Concentric Ring Electrode Based on Its Finite Dimensions Model and Confirmed by Finite Element Method Modeling

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5881
Author(s):  
Oleksandr Makeyev ◽  
Yiyao Ye-Lin ◽  
Gema Prats-Boluda ◽  
Javier Garcia-Casado
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Estimation Error ◽  
Optimization Criterion ◽  
Ring Electrode ◽  
Optimal Configuration ◽  
Concentric Ring ◽  
Finite Element Method Modeling ◽  
First Time ◽  
Element Method

The optimization performed in this study is based on the finite dimensions model of the concentric ring electrode as opposed to the negligible dimensions model used in the past. This makes the optimization problem comprehensive, as all of the electrode parameters including, for the first time, the radius of the central disc and individual widths of concentric rings, are optimized simultaneously. The optimization criterion used is maximizing the accuracy of the surface Laplacian estimation, as the ability to estimate the Laplacian at each electrode constitutes primary biomedical significance of concentric ring electrodes. For tripolar concentric ring electrodes, the optimal configuration was compared to previously proposed linearly increasing inter-ring distances and constant inter-ring distances configurations of the same size and based on the same finite dimensions model. The obtained analytic results suggest that previously proposed configurations correspond to almost two-fold and more than three-fold increases in the Laplacian estimation error compared with the optimal configuration proposed in this study, respectively. These analytic results are confirmed using finite element method modeling, which was adapted to the finite dimensions model of the concentric ring electrode for the first time. Moreover, the finite element method modeling results suggest that optimal electrode configuration may also offer improved sensitivity and spatial resolution.

scholarly journals MIXED FINITE ELEMENT FORMULATION OF THE BIHARMONIC EQUATION

2005 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
A. D. GARNADI
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Error Estimate ◽  
Biharmonic Equation ◽  
Mixed Finite Element ◽  
Mixed Finite Element Method ◽  
Element Formulation ◽  
Abstract Setting ◽  
First Time ◽  
Element Method

<p>We will provide an abstract setting for mixed finite element method for biharmonic equation. The abstract setting casts mixed finite element method for first biharmonic equation and sec- ond biharmonic equation into a single framework altogether. We provide error estimates for both type biharmonic equation, and for the first time an error estimate for the second biharmonic equation.</p>

scholarly journals Application of Finite Element Method for Analysis of Nanostructures

2017 ◽  
Vol 11 (2) ◽  
pp. 116-120 ◽  
Author(s):  
Jozef Bocko ◽  
Pavol Lengvarský
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Element Model ◽  
Geometrical Parameters ◽  
The Finite Element Method ◽  
Beam Elements ◽  
Stiffness Properties ◽  
Force Displacement ◽  
The Finite Element Model ◽  
Element Method

AbstractThe paper deals with application of the finite element method in modelling and simulation of nanostructures. The finite element model is based on beam elements with stiffness properties gained from the quantum mechanics and nonlinear spring elements with force-displacement relation are gained from Morse potential. Several basic mechanical properties of structures are computed by homogenization of nanostructure, e.g. Young's modulus, Poisson's ratio. The problems connecting with geometrical parameters of nanostructures are considered and their influences to resulting homogenized quantities are mentioned.

scholarly journals Life analysis of the bolted joint

2019 ◽  
Vol 254 ◽  
pp. 02004
Author(s):  
Milan Sapieta ◽  
Peter Sulka
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Fatigue Damage ◽  
Computational Models ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Computation Model ◽  
Life Analysis ◽  
Element Method

The paper deals with the fatigue damage calculation of 2 types of computation model of bolted joints. The study is performed via a numerical analysis with support of finite element method (FEM) software ANSYS. One model was created with a thread on the bolt, another was only bolt with cylindrical surfaces, the second model was greatly simplified. It will be evaluated the fatigue damage for both types of models. Subsequently both types of computational models will be compared in dependence on the accuracy of the results and the speed of the calculation. There are also the theoretical backgrounds for preloaded bolted joint, which was used for calculation of preload load prescribed on body of screws.

An equivalent model for sandwich panel with double-directional trapezoidal corrugated core

2019 ◽  
Vol 22 (7) ◽  
pp. 2445-2465
Author(s):  
Huimin Li ◽  
Lei Ge ◽  
Baosheng Liu ◽  
Haoran Su ◽  
Tianyi Feng ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Modulus ◽  
Sandwich Panel ◽  
Equivalent Model ◽  
Geometrical Parameters ◽  
Detailed Model ◽  
Novel Structure ◽  
Homogeneous Method ◽  
Element Method

A novel sandwich panel with double-directional corrugated core is proposed in this paper. This complex-corrugated core makes the conventional detailed finite element analysis of large structures a tough work. Thus, an equivalent homogeneous method is proposed, the key of which is to obtain the equivalent property of this novel structure. The equivalent elastic modulus considering the effect of geometrical parameters is analytically derived and verified by finite element method. Besides, equivalent shear modulus and Poisson’s ratios are obtained by finite element method. Three-dimensional detailed and equivalent models are established for further validation of this equivalent homogeneous method. Results show that elastic modulus predicted by analytical formulas is in good agreement with that by finite element method no matter how geometrical parameters change. It has been proved that stretching deformation is dominating in thickness direction, and only corrugation along loading direction can bear the load. The proposed novel sandwich structure owns better mechanical property than the conventional one with single-corrugated core. The result by equivalent model agrees well with that by detailed model, which means that this equivalent homogeneous method can well predict the macroscopic property of this novel structure.

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