Role of tangential stresses in the measurement of normal stresses by an interference method

1979 ◽  
Vol 37 (3) ◽  
pp. 1076-1079
Author(s):  
A. A. Sharts
1999 ◽  
Vol 43 (5) ◽  
pp. 1213-1237 ◽  
Author(s):  
Jeffrey F. Morris ◽  
Fabienne Boulay

2018 ◽  
Vol 230 ◽  
pp. 02027 ◽  
Author(s):  
Olena Romashko ◽  
Vasyl Romashko

The scheme of stressed state changes of the concrete contact layer and reinforcing rod during its pulling out of concrete is considered. The most important drawbacks of the known methods for evaluating the bond strength of reinforcement to concrete have been analyzed. Particular attention is focused on bond estimating by average tangential stresses. It is substantiated why the linear dependence of these stresses on normal stresses in the reinforcement cannot cover the processes of reinforcement bonding with concrete in the stage of use of reinforced concrete elements. A universal dependence of the average tangential stresses for estimating the reinforcement bond to concrete at any stage of elements deformation is proposed. Statistical evaluation of the obtained dependence was made on the basis of theoretical and experimental values of the average tangential bonding stresses comparison. The area of use of reinforcement bond with concrete average stresses dependence is defined.


Author(s):  
Vasyl Muzychuk ◽  
Oleksii Tokarchuk

The method of determination of contact normal and tangential stresses during rolling is considered, taking into account the development of deformation over time. There are many methods for determining the contact normal and tangential stresses, but they all consider the distribution along the strain boundary. This approach to solving problems does not allow to take into account the uneven deformation in the transverse direction and the influence of lateral non-contact zones adjacent to the actual deformation center. These factors should be taken into account when determining the tangent and normal stresses when rolling in calibers with different ratios of geometric shapes and rolling billet. Also, existing methods of determining contact normal and tangential stresses do not take into account the development of deformation over time. Deriving the equations that determine the deformation force of the friction force and pressure, it was assumed that the normal to the plane would not coincide with any of the axes of the coordinate system, and the inclined platform was considered as an inclined section in the parallelepiped voltage across the edges of the volume, which is distributed uniformly. The obtained formulas for determining the normal and tangent contact stresses in the deformation zone take into account rolling in calibers with different ratio of geometric shapes and rolling billet, characterize the dynamics of change of the deformation cell in time. The paper deals with rolling of AK6 alloy workpieces having Ø25x150 mm dimensions in oval caliber, with a height of 13 mm and a width of 29 mm and calculated normal and contact stresses. The plots of normal and tangent stresses show a change in the value of stress with increasing contact area and deformation time. The results of studies of normal and tangent stresses show a change in their values with increasing contact area and deformation time. When checking the proposed method, the discrepancy between the results of the theoretical calculation and the experimental data is not more than 4%, which confirms the possibility of using the method to determine the contact normal and tangential stresses during rolling.


Geophysics ◽  
2014 ◽  
Vol 79 (4) ◽  
pp. C91-C96 ◽  
Author(s):  
M. Ahmadi ◽  
A. Dahi Taleghani ◽  
C. M. Sayers

The effect of a fracture on seismic wave propagation can be represented in terms of the normal and shear fracture compliance. In many studies, fractures are assumed to have no preferential orientation for slip along the fracture plane. However, examination of fractures found in recovered cores or in exposed outcrops shows irregularities, such as hackles or slickensides, which are formed in the direction of joint/fault propagation. These irregularities, represented as sawtooth ridges, can be expected to facilitate movement in a particular direction more than the opposite direction, in a way that depends on the height and shape of the irregularities. As a result, fractured rocks should exhibit a different compliance for shear in one direction compared with shear in the opposite orientation. We used numerical modeling to offer a critical assessment of this phenomenon by directly calculating the change in normal and shear compliance in the presence of hackles. The effect of the geometry of the hackles, the friction coefficient between fracture surfaces, and the role of normal stresses on the ratio of normal-to-shear fracture compliance were evaluated.


Author(s):  
C. H. Liu ◽  
Chi-Hwa Wu ◽  
Yin-Tien Wang

In this paper we study the instability of biped robots that is a combination of both sliding and tipping over. Specifically, when robot falling occurs, the ground reaction forces and moments on a foot may determine if sliding also happens. We deal with the situation that tipping over is impending, and treat the following three possible types of contact stress distribution on the foot: point contact, line contact, and area contact. In line and area contact regions we assume that normal stresses are Hertzian, then tangential stresses may be determined by utilizing theory of instantaneous center of zero velocity in planar kinematics. From these normal and tangential stresses we may determine force combinations that cause sliding.


JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  

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