Estimation of Radial Stress in Lenses

2017 ◽  
Author(s):  
Paul R. Yoder
Keyword(s):  
Radial Stress

scholarly journals Quantitative Evaluation of Ground Movements Caused by Grouting during Shield Tunnelling in Clay

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Zhi-Feng Wang ◽  
Wen-Chieh Cheng ◽  
Ya-Qiong Wang
Keyword(s):  
Cylindrical Cavity ◽  
Radial Stress ◽  
Soft Soil ◽  
Tunnel Construction ◽  
Reliable Measure ◽  
Simple Method ◽  
Ground Movements ◽  
Tunnel Boring ◽  
Shield Tunnelling ◽  
London Clay

Grouting has been deemed as one of the most effective measures for mitigation of ground movements during tunnel construction in soft soil. Notwithstanding that, a reliable measure to quantitatively evaluate the grouting-induced ground movements during shield tunnelling in soft soil has not yet been developed. This paper presents a simple method capable of quantitatively estimating the ground movements associated with grouting for tunnel-boring operations where the grouting parameters and soil properties are taken into consideration. The grouting process is simplified as the expansion of a cylindrical cavity with a uniform radial stress applied at soil-grout interface in a half plane, and the analytical solution proposed by Verruijt is introduced for determining the ground movements by the expansion of the cylindrical cavity. The proposed method is verified with a case history undertaken in London Clay. The results obtained suggest that this procedure would be helpful in managing the grouting parameters adopted in upcoming soft ground tunnelling project and mitigating the environmental impacts on nearby properties.

The Buckling of a Circular Plate With a Concentric Circular Hot-Spot

1960 ◽  
Vol 64 (590) ◽  
pp. 105-106 ◽  
Author(s):  
K. I. McKenzie
Keyword(s):  
Critical Temperature ◽  
Circular Plate ◽  
Radial Stress ◽  
Hot Spot ◽  
Clamped Plate ◽  
Inverse Square Law ◽  
Cold Part

If a circular plate has a concentric circular hot area, there is a critical temperature for this area at which the plate buckles. This temperature is calculated in this note for the case of a clamped plate supported in such a way that the radial stress in the cold part obeys the inverse square law.

Stresses in Rotating Disks at High Temperatures

1946 ◽  
Vol 13 (1) ◽  
pp. A45-A52
Author(s):  
A. Stanley Thompson
Keyword(s):  
Radial Stress ◽  
Coefficient Of Thermal Expansion ◽  
Variable Temperature ◽  
Rotating Disk ◽  
Allowable Stress ◽  
Tabular Form ◽  
Rotating Disks ◽  
Elasticity Coefficient ◽  
Plastic Disk ◽  
General Method

Abstract A general method was found by which the problem of the rotating disk with any arbitrary profile could be solved, including the effect of plastic flow and of variable temperature, and including the change with temperature of modulus of elasticity, coefficient of thermal expansion, and allowable stress. The solution requires for its application to a specific disk only the elementary arithmetic involved in completion of a tabular form sheet. Two applications of the method are made. For an arbitrary disk profile, an integral equation was found which converges rapidly to the radial stress distribution in a series of successive substitutions. For an arbitrary choice of radial stress, the necessary disk profile can be found in one calculation. Appendix 1 gives an example of the use of the method for the design of a partially plastic disk with a central hole.

Stress Relaxation in Press-Fitted Joints

1976 ◽  
Vol 98 (1) ◽  
pp. 137-140 ◽  
Author(s):  
R. P. Goel
Keyword(s):  
Steady State ◽  
Stress Relaxation ◽  
Circular Plate ◽  
Contact Force ◽  
Radial Stress ◽  
Printed Circuit Boards ◽  
Stress Component ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Relaxation Characteristics

When contact pins, wire wrap posts, etc., are press fitted into printed circuit boards, the contact force at the interface of a post and plate relaxes with time. Much of the relaxation of the contact force occurs immediately after the connection has been made. Theoretical estimates on the reduction in contact force until a steady state (a steady state is assumed to be reached when the stress rates become 1 percent of their initial values) is reached are presented. Since most of the relaxation of the radial stress component occurs in the vicinity of the hole, the effect of adjacent joints on the relaxation characteristics of a joint are neglected. And, therefore, only an idealized geometry of a thin circular plate with a single press-fitted hole is considered.

Creep deformation and stress analysis in a transversely material disk subjected to rigid shaft

2019 ◽  
Vol 25 (1) ◽  
pp. 17-25
Author(s):  
Pankaj Thakur ◽  
Monika Sethi
Keyword(s):  
Stress Analysis ◽  
Creep Deformation ◽  
Radial Stress ◽  
Hoop Stress ◽  
Rotating Disk ◽  
Angular Speed ◽  
Transition Theory ◽  
Strain Rates ◽  
Maximum Value ◽  
Inner Surface

The purpose of this paper is to present a study of creep deformation and stress analysis in a transversely material disk subjected to the rigid shaft by using Seth’s transition theory. It has been observed that radial stress has the maximum value at the inner surface of the rotating disk made of isotropic material as compared to the hoop stress and this value of radial stress further increases with the increase in the value of angular speed. Strain rates have maximum values at the inner surface for the disk made of transversely material.

Peribronchial pressure in excised dog lungs

1978 ◽  
Vol 45 (6) ◽  
pp. 858-869 ◽  
Author(s):  
H. Sasaki ◽  
F. G. Hoppin ◽  
T. Takishima
Keyword(s):  
Smooth Muscle ◽  
Lung Volume ◽  
Radial Stress ◽  
Similar Magnitude ◽  
Alveolar Pressure ◽  
Lung Inflation ◽  
Bronchial Wall ◽  
Lobar Bronchus ◽  
Intrabronchial Pressure

To characterize the stresses which determine bronchial diameter in the lung, we estimated peribronchial pressure (Px) relative to intrabronchial pressure (Pbr) and to alveolar pressure (PA) for the main lobar bronchus of excised dog lobes using the technique of Takishima et al. (J. Appl. Physiol. 38: 875--881, 1975). The recoil of the bronchial wall, Pbr---Px, when smooth muscle was relaxed varied primarily with bronchial diameter. The recoil of the parenchyma around the bronchus, Px---Pa, varied with lung volume but was also diameter-dependent and served to double approximately the effective elastance of the bronchus in situ. We estimated recoils during slow deflations from TLC with the bronchus untreated, or pharmacologically contracted or relaxed. In untreated and relaxed states, local parenchymal and bronchial recoils were of similar magnitude to overall lung recoil (i.e., Px congruent to Ppl) except at high inflating pressure (PA -- Ppl = 30 cmH2O) where they were about half as great. With contraction, bronchial and local parenchymal recoils increased to as much as twice overall lung recoil. Contracted smooth muscle exerted a radial stress of 36+/-14 cmH2O at full lung inflation but much less during stepwise deflation.

scholarly journals Study of the Construction Sequence of Overlapping Tunnels by the Shield Tunneling Method: A Case Study of the Longest Overlapping Tunnel in China

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhiyong Yang ◽  
Yaowen Ding ◽  
Yusheng Jiang ◽  
Kuanda Fang ◽  
Linwei Dong ◽  
...  
Keyword(s):  
Working Conditions ◽  
Radial Stress ◽  
Three Dimensional ◽  
Vertical Displacement ◽  
Tunnel Lining ◽  
Shield Tunneling ◽  
Construction Sequence ◽  
Tunneling Method ◽  
The Difference ◽  
Small Change

In this study, the reasonable construction sequence of an overlapping tunnel shield is investigated. Taking the overlapping tunnel of Tianjin Metro Line 5 as the background, a three-dimensional numerical model was established using Flac3D software to study the influence of the “first up and then down” and “first down and then up” construction sequences of the overlapping tunnel on the surface settlement, stratum displacement, lining radial stress, and displacement. The research results show that the shape and width of the final settlement tank on the ground under the two conditions are basically the same, and the difference between the maximum cumulative settlements is small. The accumulated ground settlement caused by the first up and then down construction sequence is 1.8 mm larger than that caused by the first down and then up sequence. The difference between the two working conditions on the vertical displacement of the stratum mainly occurs in the middle stratum of the upper and lower tunnels, and the proportion of the strata in the uplifted state and subsidence state is different. The construction sequence has little effect on the radial stress on the lining of the upper and lower tunnels. Under these two conditions, the excavation of the second tunnel causes a small change in the radial stress of the preceding tunnel lining, both within 4.2%. Under the working condition of first down and then up, the construction of the second tunnel causes the lining of the preceding tunnel to rise by 7.2∼9.2 mm. Under the condition of first up and then down, the construction of the second tunnel causes the lining of the preceding tunnel to sink again by 9.1∼10.4 mm. By comparing the effects of the two working conditions on the stratum and the tunnel lining, it is recommended that the construction be carried out in the order of first down and then up.

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