Analytical Solutions for Stress and Displacement Fields in Disks under Arbitrarily Distributed Loads

2017 ◽  
Vol 14 (06) ◽  
pp. 1750060
Author(s):  
Dexuan Qi ◽  
Yongshu Jiao ◽  
Lingling Pan

The general series solution (GSS) approach is presented, in order to determine the stress and displacement fields in disks under arbitrarily distributed normal and tangential loads. An Airy stress function in series form is selected. Stresses are expressed by infinite coefficients. Thus displacements are expressed by the infinite stress coefficients. And self-equilibrated loads acting on the side edge are extended to Fourier series. Stress coefficients are related to loading coefficients by stress boundary conditions. Then five examples show the validity of this approach. The GSS approach might lead to industrial applications in rock mechanics, petroleum and mining engineering, etc.

1965 ◽  
Vol 32 (1) ◽  
pp. 21-25 ◽  
Author(s):  
R. A. Eubanks

An explicit series solution is presented for the stress and displacement fields in an elastic body of infinite extent containing two equidiameter spherical cavities. At large distances from the cavities the displacement field coincides with that which arises from pure torsion about the axis of symmetry. Numerical results are presented in graphs which demonstrate the interference of the two sources of stress concentration.


1992 ◽  
Vol 114 (3) ◽  
pp. 540-551 ◽  
Author(s):  
Hsing-Sen S. Hsiao ◽  
Bernard J. Hamrock

A complete solution is obtained for elastohydrodynamically lubricated conjunctions in line contacts considering the effects of temperature and the non-Newtonian characteristics of lubricants with limiting shear strength. The complete fast approach is used to solve the thermal Reynolds equation by using the complete circular non-Newtonian fluid model and considering both velocity and stress boundary conditions. The reason and the occasion to incorporate stress boundary conditions for the circular model are discussed. A conservative form of the energy equation is developed by using the finite control volume approach. Analytical solutions for solid surface temperatures that consider two-dimensional heat flow within the solids are used. A straightforward finite difference method, successive over-relaxation by lines, is employed to solve the energy equation. Results of thermal effects on film shape, pressure profile, streamlines, and friction coefficient are presented.


1967 ◽  
Vol 89 (2) ◽  
pp. 203-210 ◽  
Author(s):  
R. R. Donaldson

Reynolds’ equation for a full finite journal bearing lubricated by an incompressible fluid is solved by separation of variables to yield a general series solution. A resulting Hill equation is solved by Fourier series methods, and accurate eigenvalues and eigenvectors are calculated with a digital computer. The finite Sommerfeld problem is solved as an example, and precise values for the bearing load capacity are presented. Comparisons are made with the methods and numerical results of other authors.


1989 ◽  
Vol 111 (4) ◽  
pp. 243-248 ◽  
Author(s):  
T. Hattori ◽  
S. Sakata ◽  
G. Murakami

Since the stress and displacement fields near a bonding edge show singularity behaviors, the adhesive strength evaluation method, using maximum stresses calculated by a numerical stress analysis such as the finite element method, is generally not valid. In this paper, a new method, which uses two stress singularity parameters, is presented for evaluating adhesive strength. This method is applied to several kinds of molded models, composed of epoxy base resin and Fe-Ni alloy sheets, and plastic encapsulated LSI models. Predictions about the initiation and extension of delamination are compared with the results of observations made by scanning acoustic tomography on these models.


Starting with the three-dimensional equations of classical isotropic elasticity, equations are obtained for boundary-layer effects near any smooth edge of an elastic shell. Solutions of these equations are combined with solutions of the equations of the 'interior’ problem so that any specified edge conditions in terms of stresses can be satisfied. The usual Kirchhoff stress boundary conditions for the major terms of the interior stresses are deduced from the analysis.


Author(s):  
Peng Qi ◽  
Hongbin Liu ◽  
Lakmal Seneviratne ◽  
Kaspar Althoefer

Flexible robot arms have been developed for various medical and industrial applications because of their compliant structures enabling safe environmental interactions. This paper introduces a novel flexible robot arm comprising a number of elastically deformable planar spring elements arranged in series. The effects of flexure design variations on their layer compliance properties are investigated. Numerical studies of the different layer configurations are presented and finite Element Analysis (FEA) simulation is conducted. Based on the suspended platform’s motion of each planar spring, this paper then provides a new method for kinematic modeling of the proposed robot arm. The approach is based on the concept of simultaneous rotation and the use of Rodrigues’ rotation formula and is applicable to a wide class of continuum-style robot arms. At last, the flexible robot arms respectively integrated with two different types of compliance layers are prototyped. Preliminary test results are reported.


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