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Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The compression deformation of the measuring membrane of the differential pressure capacitance sensor is studied. The classical von Kármán thin plate theory is applied to the elastic circular thin plate subjected to pretension, and the approximate analytical solution is given by adopting the homotopy analysis method. The results are compared with the simulation results of the finite element software ANSYS, which shows that they have a high degree of agreement. The magnitude of pretension has a great influence on the deformation of the membrane under compression, thus affecting the capacitance output characteristics of the sensor. The effect of pretension on the nonlinear characteristic of the sensor is verified by the sensor performance test. The results suggest that the linearity of the sensor can be effectively improved by selecting the appropriate pretension, and the sensitivity of the output can be improved by appropriately reducing the membrane thickness. The analysis results have an important reference value for the design of membrane of differential pressure capacitance sensors.

Copyright of Journal of Shanghai Jiao Tong University (1006-2467) is the property of Journal of Shanghai Jiao Tong University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The wind deflection of the sealing net across the transmission line is great under the slipstream of high-speed train. Based on the existing research， the paper proposes a method to reduce the wind deflection response of the sealing net structure by using the inclined wind vibration control cable， and it establishes a numerical model of dynamic response with wind analysis model and the sealing network structure of high-speed train coupled. Moreover， it studies the effect of the inclined wind vibration control cable on the wind deflection control of the sealing net structure and compares the effect with that of the vertical wind vibration control cable without inclined guy cable. The results show that under the action of coupled high-speed train wind， the pretension of the bearing cable has a significant effect on the horizontal and vertical wind deflection of the sealing net， especially the vertical wind deflection control of the sealing net， which can be reduced by 90% or more， but the safety coefficient of the bearing cable will be reduced by excessive large pretension force； the proposed schemes of using the inclined wind vibration control cable and the vertical wind vibration control cable are about the same in the control effect， and both can effectively control the upper and lower wind deflection of the sealing network. The control effect is more significant in the working condition of smaller carrier cable pretension.

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to research the morphology and mechanical properties of submarine cable during laying operations, a semi-analytical approximation of a two-dimensional in-plane mechanical behavior along ocean depth during laying operations is presented, with considering the coupling effect of submarine cable's tension, self-weight and the sea buoyancy. In the analysis, the mechanics equilibrium equations, that is a set of non-linear differential equations of a short section of submarine cable are established with using Newton's laws of motion, which is comprehensively considering submarine cable elevation angle, configuration and tension change during laying operations and analyzing in-plane mechanical behavior of submarine cables. Through numerical simulation calculation in numerical examples, the submarine cable's tension almost varies linearly with the water depth and the effect of payout rate on submarine cables during laying operations relative to submarine cable self-weight, cable ship velocity, and the pretension is negligible. [ABSTRACT FROM AUTHOR]

With high strength anchor system being widely applied for rock control in the deep and complex soft roadways, whereas insufficient recognition has been attained as far as the anchoring bolt body formation and destabilization are concerned. Adopting numerical simulation, authors studied the formation factors of the anchor in the use of pretension and the destabilization mechanisms of the anchor resulting from the in-situ stress. The results indicate that when the pretension is fixed, the smaller the bolt spacing is, the stronger the induced stress will be. The induced stress shapes as spindle in the range of rock anchored, whist the stress gradually decreases from the surface of the roadway, therefore the stress distributing in "cone" shape at the anchor head. When the anchor area is rather confined or the pretension is rather strong, compression zone and the anchoring range will be expanding. However, the length of the anchoring area has dramatic influence on the anchor bolt body. In the context of in-situ stress, the types of instable anchor solid consist of anchor bolt rupture type, anchoring debonding type, rock dominant failure type, anchor solid composite failure type. In a descending order,the rock strength,bolt pretension,side pressure coefficient of in-situ stress, the cover depth, and bolt spacing will destabilize the anchor bolt. [ABSTRACT FROM AUTHOR]

Bolt pretension has an important part in roadway support, but the study on strengthening characteristics of anchorage body with pre-stressed bolts still has many problems. Mechanics characteristics of detached anchorage body was researched by using RMT-150C testing machine, which was fabricated by wax-sand, pretension bolts and plainstrain restrain device. The results indicate that strength enhancement factor of peak strength, residual strength are positive correlation with rock strength and pretension of bolts. Strength enhancement factor is gradually increasing with pretension when rock strength is constant, and the residual strength enhancement factor of pretention of is greater than that of peak. There are corresponding relationship with stress-strain curve and bolts loads. Congruent relationship exists between stress-strain curve and bolt load. Before surrender point, bolt load increases slowly; however which increases rapidly after surrender point. Bolt load increases gradually on post-peak points, and constantly descends on flow phase. The higher strength of rock is, the lower increase rate of bolts loads are with the same pretension. The increase rate smaller is, the higher pretension is with the same rock. The loss of pretension in failure stage is much more of soft rock than that of hard rock. The strengthening effect in soft rock is obvious than that of in hard rock. Site practice shows that surrounding rock deformation can be decreased effectively with high bolt pretension. [ABSTRACT FROM AUTHOR]