On the existence of thermomechanical surface in materials under nonisothermal repeated simple loading

2006 ◽  
Vol 38 (5) ◽  
pp. 458-465
Author(s):  
B. I. Koval’chuk ◽  
A. A. Lebedev
2002 ◽  
Vol 125 (1) ◽  
pp. 52-59 ◽  
Author(s):  
N. Ye ◽  
K. Komvopoulos

The simultaneous effects of mechanical and thermal surface loadings on the deformation of layered media were analyzed with the finite element method. A three-dimensional model of an elastic sphere sliding over an elastic-plastic layered medium was developed and validated by comparing finite element results with analytical and numerical solutions for the stresses and temperature distribution at the surface of an elastic homogeneous half-space. The evolution of deformation in the layered medium due to thermomechanical surface loading is interpreted in light of the dependence of temperature, von Mises equivalent stress, first principal stress, and equivalent plastic strain on the layer thickness, Peclet number, and sliding distance. The propensity for plastic flow and microcracking in the layered medium is discussed in terms of the thickness and thermal properties of the layer, sliding speed, medium compliance, and normal load. It is shown that frictional shear traction and thermal loading promote stress intensification and plasticity, especially in the case of relatively thin layers exhibiting low thermal conductivity.


2015 ◽  
Vol 52 (12) ◽  
pp. 2008-2016 ◽  
Author(s):  
Yang Sun ◽  
Jing-bo Su ◽  
Xiao-he Xia ◽  
Zheng-liang Xu

The disturbance of the soil behind the reaction wall of an open caisson can affect the efficiency and safety of jacking operation and control. This study focuses on the deformation of the soil mass behind the reaction wall used to support the jack. The stress–strain relationship of the soil behind the reaction wall was analysed, providing a theoretical basis for determining the most unfavourable combination of reactive forces using a computational model. A three-dimensional finite element model for this problem was developed, and a simple loading scenario was implemented. In addition, the mechanism of the deformation of the soil induced by horizontal parallel pipe jacking was also analysed. The results showed that for the soil behind the reaction wall of the open caisson, the uplift deformation of the soil surface increased initially and later gradually decreased, eventually achieving stability. The reaction force had a relatively obvious effect on the deformation of the soil within the range of the reaction wall burial depth and the horizontal displacement of the soil along the length of the reaction wall. The maximum displacement occurred near the axis of symmetry of the reaction wall. In addition, to consider the cyclic characteristics of the reaction force, the shakedown theorem is introduced to the deformation analysis of the soil and compared with the results obtained from simple loading. It was shown that the two deformation analysis methods have certain scopes of application, depending on the individual engineering requirements.


1982 ◽  
Vol 17 (1) ◽  
pp. 1-8 ◽  
Author(s):  
P J Holt ◽  
J P H Webber

A consistent set of equations is given for honeycomb sandwich shells, wherein each layer of the sandwich is treated separately. The theory allows for the effects of thick cores, non-constant core thickness and arbitrary anisotropic faces. Analytical solutions are obtained for constant thickness and tapered beams, a flat plate, and a circular cylinder subjected to simple loading conditions. The principal use of such solutions is in the testing of finite elements which are intended to model honeycomb sandwich construction.


1986 ◽  
Vol 21 (4) ◽  
pp. 185-195 ◽  
Author(s):  
P D Soden ◽  
M A Millar ◽  
B A Adeyefa ◽  
Y S Wong

A bicycle frame has been analysed as a three-dimensional framework and stresses and deflections predicted using a finite element computer program. Theoretical results for simple loading case were compared with strain gauge measurements in laboratory tests. More complex loading cases representing common cycle racing situations were analysed. The largest stresses in the frame were bending stresses. Stresses in the region of 300—400 MN/m2 were predicted in the down tube and right chain stay during starting and stresses of about 250 MN/m2 at the front of the top tube and down tube during severe braking.


1966 ◽  
Vol 8 (4) ◽  
pp. 257-260
Author(s):  
M. L. Bernshtein ◽  
G. P. Kalyagina ◽  
L. M. Kaputkina ◽  
D. V. Laptev

1948 ◽  
Vol 26f (12) ◽  
pp. 552-564
Author(s):  
I. F. Morrison

This paper contains but a single idea. Its purpose is to show how, by the use of Kleinlogel's Rahmenformeln, the number of simultaneous linear equations that occur in the analysis of indeterminate structures can be reduced materially by using a primary structure, itself made up of indeterminate parts, provided the bending moment diagrams can be drawn for them. These are obtained from the Rahmenformeln. In order to recall to the reader's mind the well known moment-area method a brief summary of that process is included. A practical numerical example of the analysis of a frame indeterminate to the seventh degree is worked out in detail. Two arrangements of the indeterminate-components are chosen in the illustrative example. The final bending moment diagram is shown for a simple loading case and the influence line for the bending moment at one point is discussed briefly.


1974 ◽  
Vol 16 (9) ◽  
pp. 787-789 ◽  
Author(s):  
E. D. Tsypkina ◽  
V. S. Sysoeva ◽  
G. A. Chumak ◽  
S. S. Marchenko

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