Integration of design of experiment and finite element method for the study of geometrical parameters in metallic bipolar plates for PEMFCs

Author(s):  
F. Ahmadi Khatir ◽  
M.M. Barzegari ◽  
H. Talebi-Ghadikolaee ◽  
S. Seddighi
2018 ◽  
Vol 196 ◽  
pp. 01011
Author(s):  
Oleg Negrozov ◽  
Pavel Akimov ◽  
Marina Mozgaleva

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.


2017 ◽  
Vol 11 (2) ◽  
pp. 116-120 ◽  
Author(s):  
Jozef Bocko ◽  
Pavol Lengvarský

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.


2020 ◽  
Vol 2020 (6) ◽  
pp. 12-21
Author(s):  
Ruslan Guchinskiy

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.


2019 ◽  
Vol 22 (7) ◽  
pp. 2445-2465
Author(s):  
Huimin Li ◽  
Lei Ge ◽  
Baosheng Liu ◽  
Haoran Su ◽  
Tianyi Feng ◽  
...  

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.


2013 ◽  
Vol 405-408 ◽  
pp. 3165-3168 ◽  
Author(s):  
Pavel A. Akimov ◽  
Marina L. Mozgaleva

High-accuracy solution of the problem of deep beam analysis is normally required in some pre-known domains (regions with the risk of significant stresses that could potentially lead to the destruction of structure, regions which are subject to specific operational requirements). The distinctive paper is devoted to correct wavelet-based multilevel discrete-continual finite element method for local analysis of deep beams with regular (in particular, constant or piecewise constant) physical and geometrical parameters (properties) in one direction. Initial discrete-continual operational formulation of the considering problem and corresponding operational formulation with the use of wavelet basis are presented. Due to special algorithms of averaging within multigrid approach, reduction of the problem is provided. Resultant multipoint boundary problem of structural mechanics for system of ordinary differential equations with piecewise-constant coefficients is given.


2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Mohammad Ali Goudarzi

Liquid-roof interaction imposes a complicated distribution of out-of-plane deformation on the single-deck type floating roof (SDRF), which is the main source of considerable seismic stresses in floating roof. In this paper, an analytical solution for evaluating the dynamic interaction between the liquid and the floating roof is developed. Main physical and geometrical parameters are involved by the proposed analytical solution (PAS) for evaluating the seismic stresses of a single deck floating roof tanks (SDFR). The results of PAS are compared with the results of existing empirical formulas for various dimensions of SDRF tanks. In order to assess the validity of PAS for various sloshing wave height, a numerical model based on finite element method is established and the PAS results are compared with the finite element method (FEM) analysis results. The PAS predictions are in very good agreement with both the available empirical formula and the numerical model results.


2019 ◽  
pp. 88-94
Author(s):  
Владимир Николаевич Доценко ◽  
Иван Григорьевич Лихошерст ◽  
Мелания Николаевна Бурда

In this article, the task is to consider the effect of the piston bending in an axial- piston pump under the action of hydraulic force on the kinematics of the pump. The change in kinematics due to the elastic deformation of the piston is estimated by the axial displacement of the piston face. The study takes into account the bias of the plunger in the gap, the elastic bending deformation of the plunger, the contact deformation of the plunger and the cylinder block. The task is considered on three models: a rigid piston in a rigid cylinder block; deformable piston in a rigid cylinder block; deformable piston, block, shoe, and disk. The values of the displacement of the piston, caused by elastic forces and misalignment in the gap depending on its position were obtained for the first time as a result of the analysis. The problem is solved both analytically and numerically using the finite element method. In the analytical solution of the problem, the piston is represented as a beam supported by pin and roller at the points of contact of the piston with the walls of the cylinder block. The three-dimensional model of the pump is applied to solve the problem by the finite element method, the contact deformation of the piston and the block is considered. According to the simulation results, the displacement of the piston is obtained depending on the position of the piston. The results of modeling an analytical model are presented in the form of a smooth function, and the results of numerical simulation using the finite-element method obtained for several points are interpolated by a smooth function. The conclusions suggest that the greatest deformations are achieved in the piston located at the bottom dead center, and the gap between the piston and the sleeve and the overall stiffness of the contact parts have the greatest effect. The results of the work can be used to correct the geometrical parameters of a heavily loaded aviation axial-plunger pump to reduce flow and pressure pulsations caused by the kinematics of the pump.


Sign in / Sign up

Export Citation Format

Share Document