scholarly journals Areas of Contact and Pressure Distribution in Bolted Joints

1972 ◽  
Vol 94 (3) ◽  
pp. 864-870 ◽  
Author(s):  
H. H. Gould ◽  
B. B. Mikic

The pressure distribution in the contact zones and the radii at which flat and smooth axisymmetric, linear elastic plates will separate were computed for several thicknesses as a function of the configuration of the bolt load by the finite element method. The radii of separation were also measured by two experimental methods. One method employed autoradiographic techniques. The other method measured the polished area around the bolt hole of the plates caused by sliding under load in the contact zone. The computational and experimental results are in agreement and these yield smaller zones of contact than indicated by the literature. It is shown that the discrepancy is due to an assumption made in the previous analyses.

Author(s):  
Ye-Chen Lai ◽  
Timothy C. S. Liang ◽  
Zhenxue Jia

Abstract Based on hierarchic shape functions and an effective convergence procedure, the p-version and h-p adaptive analysis capabilities were incorporated into a finite element software system, called COSMOS/M. The range of the polynomial orders can be varied from 1 to 10 for two dimensional linear elastic analysis. In the h-p adaptive analysis process, a refined mesh are first achieved via adaptive h-refinement. The p-refinement is then added on to the h-version designed mesh by uniformly increasing the degree of the polynomials. Some numerical results computed by COSMOS/M are presented to illustrate the performance of these p and h-p analysis capabilities.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4842
Author(s):  
Huanping Yang ◽  
Wei Zhuang ◽  
Wenbin Yan ◽  
Yaomian Wang

The nanoindentation loading response of elastoplastic materials was simulated by the finite element method (FEM). The influence of the Young’s modulus E, yield stress σy, strain hardening exponent n and Poisson’s ratio ν on the loading response was investigated. Based on an equivalent model, an equation with physical meaning was proposed to quantitatively describe the influence. The calculations agree well with the FEM simulations and experimental results in literature. Comparisons with the predictions using equations in the literature also show the reliability of the proposed equation. The investigations show that the loading curvature C increases with increasing E, σy, n and ν. The increase rates of C with E, σy, n and ν are different for their different influences on the flow stress after yielding. It is also found that the influence of one of the four mechanical parameters on C can be affected by the other mechanical parameters.


The finite element method has become established as a powerful tool for the solution of many problems of continuum mechanics where its physical interpretation, by analogy with discrete problems of structural analysis permits the user to exercise a considerable degree of insight and judgement in its use. Further it is now a recognized mathematical procedure of approximation which embraces many older methodologies (such as the finite difference method) as a subclass. In the field of geological studies its impact is fairly recent and only a limited application has been made to date. The techniques used here have been limited to those established over a decade ago in the parallel fields and recent developments and possibilities barely touched upon. In this paper the author therefore attempts to ( a ) outline some of the general mathematical and practical aspects of the method with illustrations from various fields which are relevant to geological problems, ( b ) survey accomplishments already made in geology and geotechnical fields, and ( c ) suggest some possible new extensions of application.


1979 ◽  
Vol 21 (1) ◽  
pp. 25-32 ◽  
Author(s):  
M. Burdekin ◽  
N. Back ◽  
A. Cowley

This paper presents a general method for calculating the pressure distribution and the deformations in machine joints. This method assumes that the components of the joint are connected through finite elements which are defined as a function of the surface finish, material and pressure at the apparent area of contact. The system so established is solved in an iterative manner using the finite-element method, obtaining, as a final result, the pressure distribution at the contacting surfaces of the components and the deformations of the surrounding body. To prove the validity and precision of the theoretical formulation, several examples of joints are considered where the correlation between the calculated and measured deflections is shown to be good.


2009 ◽  
Vol 46 (6) ◽  
pp. 627-638 ◽  
Author(s):  
Nainan P. Kurian ◽  
Syed J. Shah

A circular pile with helical blades is an old type of foundation, which has staged a comeback recently and is being used in a variety of situations. Most of the research on helical screw piles has been experimental or theoretical with the help of simplifying assumptions. The method of design adopted so far treats this pile as an annular plate, disregarding the intricacies of the geometry of the helix. It is only the versatility of the finite element method that can take into account the actual geometry of a spatial structure such as the helical blade at a microlevel. This is perhaps the first attempt at such an analysis to study the response of the helical screw pile within the elastic and nonlinear ranges. While the pile is linearly elastic, soil is considered both as a linear elastic medium and as an elastic–plastic medium following the Drucker–Prager constitutive model. Cases of smooth contact and frictional contact between soil and screw pile are also considered. Screw piles are studied under compressive, tensile, and lateral loading conditions. Moreover, their performance is compared with that of prismatic piles. A parametric study has also been attempted on some key geometrical features of the screw pile.


2013 ◽  
Vol 25 (2) ◽  
pp. 324-332 ◽  
Author(s):  
Kazuo Okuda ◽  
◽  
Keiji Saneyoshi ◽  

A new stacked-type electrostatic actuator with two ribbon films has been developed to be applied to artificial muscles. In this paper, spring characteristics of the actuator have been simulated and compared to measured data. There are two regions in spring characteristics of the actuator: one is the working region where the actuator contracts easily, and the other is the overload region where the actuator is extended only negligibly by the load. Spring characteristics of the actuator have been simulated by nonlinear structural analysis including the contact problem using the finite element method. It is understood that spring characteristics of working and overload regions can be improved by thinning the hinge and by thickening the electrode. The stroke of the actuator can be controlled, furthermore, by changing the length of the hinge. When the size of the actuator is reduced and actuators are integrated until they become the same volume, voltage applied to the actuator to generate the same force is reduced in proportion to the reduction rate while the actuator keeps the same spring characteristics and stroke.


2007 ◽  
Vol 3 (1) ◽  
Author(s):  
Edela Puricelli ◽  
Jun Sérgio Ono Fonseca ◽  
Marcel Fasolo de Paris ◽  
Hervandil Sant'Anna

2020 ◽  
Vol 14 (2) ◽  
pp. 197-200
Author(s):  
Carlos Alberto Costa ◽  
Vinicius Victorazzi Lain ◽  
Alexandre Leme Godoy-Santos ◽  
Victor Gonçalvez de Antoni ◽  
Paulo Roberto Linzmaier ◽  
...  

The objective of this study is to evaluate the applicability of the finite element method to analyze pressure distribution in the healthy human foot. Images of a foot were captured using computed tomography and converted into a three-dimensional model, which was adjusted with the aid of CAD software. The model was imported into Abaqus software for finite element analysis, considering the different regions of the foot. Observations of displacement, stresses, and pressure distribution demonstrated a biomechanical behavior of the foot consistent with that reported in the existing literature, regarding the regions of peak plantar pressure. These findings demonstrate the feasibility of evaluating the physical and mechanical behavior of the human foot using the finite element method, and can serve as a reference for the study and manufacture of orthotic appliances, prosthetic devices, and insoles. Level of Evidence V; Prognostic Studies; Expert Opinion.


2019 ◽  
Vol 70 (6) ◽  
pp. 1942-1946
Author(s):  
Stefan-Catalin Popescu

The paper presents stress analysis of an ankle prosthesis and the prediction of the cracks appearance that may occur using the finite element method. The first test was performed using as material for the ankle prosthesis simulation, aluminium alloy 6061, and in the second test were use titanium as the simulation material. Von Mises�s basic concept, failure theory, is also analysed, using Autodesk Inventor simulation software, in an attempt to give a perspective on the material from which the ankle prosthesis must be made. In conclusions were presented results for stress, endurance, and safety factors for simulated prosthesis.


Author(s):  
M. K. Sarwar ◽  
A. A. Shabana ◽  
Toshikazu Nakanishi

Abstract The objective of this study is to develop a design procedure that integrates multibody techniques, the finite element method, and experimental modal analysis techniques. Multibody techniques and the finite element method are first used to develop and numerically test the performance of the proposed design. Based on this computer analysis, a prototype model can be built. The vibration modal parameters of this model can be determined experimentally and used with general purpose multibody computer programs to evaluate the performance of the design. The obtained numerical results can be compared with the results obtained previously using multibody techniques and the finite element method. Adjustments can then be made in the finite element description in order to obtain a more realistic model that compares well with the experimental data. Using the more realistic finite element model, design modifications can be made in order to improve the performance of the design model. The use of the design methodology proposed in this paper is demonstrated using a flexible tracked vehicle model that consists of fifty four interconnected bodies. In this model, the nonlinear contact forces that describe the interaction between the track links and the vehicle components and the ground are developed. The nonlinear dynamic equations of the vehicle are developed in terms of a coupled set of reference and chassis elastic modal coordinates. The flexibility of the chassis of the tracked vehicle is described using the finite element method and experimentally identified modal parameters. The results obtained using the finite element model are compared with the results obtained using experimentally identified modal parameters.


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