Investigation of the stress state of thick multiply connected plates by the finite element method

1976 ◽  
Vol 8 (2) ◽  
pp. 165-170 ◽  
Author(s):  
V. V. Kirichevskii ◽  
V. N. Kislookii ◽  
A. S. Sakharov
Author(s):  
К. П. Барахов

Thin-walled structures may contain defects as cracks and holes that are leftovers of the material the construction, is made of or they occur during the operation as a result of, for example, mechanical damage. The presence of holes in the plate causes a concentration of stresses at the boundary of the holes and ultimately leads to premature failure of the structural element. Repair of local damage of modern aircraft structures can be made by creating overlays that are glued to the main structure. The overlay takes on part of the load, unloading the damaged area. This method of repair provides tightness and aerodynamic efficiency to the structure. The calculation of the stress state of such glued structures is usually performed by using the finite element method. The classic models of the stress state of overlapped joints are one-dimensional. That is, the change of the stress state along only one coordinate is considered. At the same time, the connections of a rectangular form are also considered. The purpose of this work is to create a mathematical model of the stress state of circular axisymmetric adhesive joints and to build an appropriate analytical solution to the problem. It is assumed that the bending of the plates is absent; the deformation of the plates is even by thickness. The adhesive layer works only on the shift. The main plate and the overlay are considered isotropic. The solution is built on polar coordinates. The stress state of the connection depends only on the radial coordinate, i.e. one-dimensional. The solution is obtained in analytical form. This mathematical model is a generalization of the classical model of the adhesive connection of Volkersen to a circular or annular region and is considered for the first time. Boundary conditions are met exactly. The satisfaction of marginal conditions, as well as boundary conditions, leads to a system of linear equations with respect to the unknown coefficients of the obtained solutions. The model problem is solved and the numerical results are compared with the results of calculations performed by using the finite element method. It is shown that the proposed model has sufficient accuracy for engineering problems and can be used to solve problems of the design of aerospace structures.


2017 ◽  
Vol 2 (2) ◽  
pp. 97
Author(s):  
Yu.N. Loginov ◽  
N.А. Babailov ◽  
D.N. Pervukhina

<p class="TTPAbstract">In this study, the calculation results of the briquette stress state by the Finite element method are presented. The fields of compressive and tensile stresses in briquette are determined. The conditions affecting the process of the briquette destruction are considered.</p>


2011 ◽  
Vol 71-78 ◽  
pp. 1383-1387 ◽  
Author(s):  
Wen Juan Yao ◽  
Wu Yang ◽  
Xiao Yu Liu

Taking Tianjin Yonghe bridge for example, the finite element method is adopted to simulate each stages of cable replacement process, the dates of tension, the alignment of main beam and the change of stress before and after cable replacement are compared and analysed, The measured value is greatly consistent with calculated value, Stress state of the bridge has been greatly improved, the weight of main beam bearing by the cable will be shared by a few closed cable after unloading, so the cables which are more serious corroded should be replaced.


1994 ◽  
Vol 29 (1) ◽  
pp. 7-16 ◽  
Author(s):  
G S Wang

Stress analyses are performed using the finite element method (FE) for a lug under various conditions. The effects of the clearance between pin and hole, the pin load magnitude, the contact condition, and the relative pin/lug rigidities etc. are investigated. The effect of some durability improvement techniques, such as interference fitting, bushing, and cold working are also investigated. Significant results are obtained which can improve both the understanding of the stress state in a lug and the design of a durable lug.


Author(s):  
Olga O. Aleshina ◽  
Vyacheslav N. Ivanov ◽  
David Cajamarca-Zuniga

Nowadays there are various calculation methods for solving a wide range of problems in construction, hydrodynamics, thermal conductivity, aerospace research and many other areas of industry. Analytical methods that make up one class for solving problems, and numerical calculation methods that make up another class, including those implemented in computing complexes, are used for the design and construction of various thin-walled structures such as shells. Due to the fact that thin-walled spatial structures in the form of various shells are widely used in many areas of human activity it is useful to understand and know the capabilities of different calculation methods. Research works on the study of the stress-strain state of the torse shell of equal slope with an ellipse at the base are not widely available at the moment. For the first time the derivation of the differential equations of equilibrium of momentless theory of shells to determine the normal force Nu from the action of uniformly distributed load tangentially directed along rectilinear generatrixes to the middle surface of the torse of equal slope with a directrix ellipse is presented in this article. The parameters of the stress state of the studied torse are also obtained by the finite element method and the variational-difference method. The SCAD software based on the finite element method and the program SHELLVRM written on the basis of the variational-difference method are used. The numerical results of the parameters of the stress state of the studied torse are analyzed, and the advantages and disadvantages of the analytical method and two numerical calculation methods are determined.


2021 ◽  
Vol 315 ◽  
pp. 01019
Author(s):  
Vyacheslav Gogolin ◽  
Inna Ermakova ◽  
Vyacheslav Fedusov

Two statements of the problem of calculating the stress state of pillars for a longwall recovery room are proposed. In the first statement, this pillar is located in the coal seam and is not affected by the adjacent extracted panel. The second statement takes into account the geomechanical effect of the adjacent extracted panel. The calculation area consists of the following blocks: the coal seam, the goaf, and the inter-panel pillar. All blocks are affected by their own weight. The problems are solved using the finite element method with pre-determined limiting conditions of the stress state within the solid strata.


2014 ◽  
Vol 71 (11) ◽  
pp. 1034-1039
Author(s):  
Slobodan Tabakovic ◽  
Jovan Grujic ◽  
Milan Zeljkovic ◽  
Zoran Blagojevic ◽  
Bojan Radojevic ◽  
...  

Background/Aim. One of the possible complications after implantation of a cement hip-joint endoprosthesis is fracture in the endoprosthesis body. Fractures arise from overload or material fatigue of which an implant is made. The purpose of this research was to define the intensity of maximum stress and the positions of a critical cross-section in the endoprosthesis body. Methods. Unilaterally changing forces which act on the hip joint during walking as well as the loads result in flexible deformations of the endoprosthesis body. Biomechanical analysis of the forces acting on the hip joint determine their direction and intensity, whereas on the basis of Gruen?s classification of the endoprosthesis body loosening the level of fixation is established. The bodies of cement hip joint endoprosthesis are made of cobalt-chromiummolybdenum (CoCrMo) alloy, suitable for vacuum casting, are submitted to the analysis. Analysis of the critical stress in the endoprosthesis body was performed on the endoprosthesis body by means of the finite element method. The experimental verification of the obtained results was carried out on the physical prototype under laboratory conditions. Results. Computer analysis, by means of the finite element method, determined the stress state by calculation of the maximum Von Mises stress and critical cross-sections for different angles of the resultant force action. The results obtained by the computer and experimental method correlate and are comparable to the results of similar analyses conducted on various endoprosthesis types. Conclusion. The analyses described in the paper make the basis for improving the process designing of hip joint endoprostheses and their customization to each individual patient (custom made).


Sign in / Sign up

Export Citation Format

Share Document