scholarly journals Design and Construction of the High-rise Reinforced Concrete Smokestack with Variable Cross-Section on the Soft Ground

1991 ◽  
Vol 29 (5) ◽  
pp. 47-55
Author(s):  
M. Yamakawa ◽  
T. Mukai ◽  
Y. Ogaki ◽  
H. Sakakura
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Variable Cross Section ◽  
Soft Ground ◽  
Variable Cross ◽  
High Rise ◽  
Design And Construction

scholarly journals Structural Optimization and Experimental Research of High-rise Guyed Tower

2021 ◽  
Vol 245 ◽  
pp. 02006
Author(s):  
Wu Jing ◽  
Han Junke ◽  
Ye Fang ◽  
Qi Wenyan ◽  
Yu Jinshan ◽  
...  
Keyword(s):  
Structural Optimization ◽  
Cross Section ◽  
Engineering Application ◽  
Variable Cross Section ◽  
Variable Cross ◽  
High Rise ◽  
Advantages And Disadvantages ◽  
Test Study ◽  
Uniform Cross Section ◽  
Guyed Towers

In this paper, the structural optimization of high-rise guyed tower is carried out for the guyed wire and tower column schemes. The schemes are compared from the four guyed wires and eight guyed wires, the width of the tower column, the uniform cross-section tower column and the variable cross-section tower column, etc. And the single-column tower with eight guyed wires and variable cross-section is recommended for the high-rise guyed tower. Through the full-scale test study of the high-rise guyed tower, the safety of the high-rise guyed tower structural optimization and the feasibility of engineering application are verified. According to the technical and economic analysis of traditional self-supporting towers and high-rise guyed towers recommended in this paper, it can be seen that the weight and total cost of the high-rise guyed towers are 75.3% and 88.5% of the traditional self-supporting towers respectively, demonstrating the technical and economic advantages of the high-rise guyed towers. The advantages and disadvantages of high-rise guyed towers and self-supporting towers are summarized for reference in engineering design.

Cable stayed bridge over the Crati river in Cosenza

2021 ◽  
Author(s):  
Pierangelo Pistoletti ◽  
Marcello Vaccarezza ◽  
Simone Varni ◽  
Paolo Roggero ◽  
Marco Sciarra
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Concrete Structure ◽  
Constant Width ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Middle Plane ◽  
Reinforced Concrete Structure ◽  
Cable Stayed Bridge ◽  
The City

<p>The “Bridge over the Crati River” is a cable stayed bridge in a single span of 114.725m, designed by the architect Santiago Calatrava for the city of Cosenza. The main elements are the main tower, the deck, the cables, the reinforced concrete pier and the abutments; one of those is the restraint of the main rear cables. The steel tower has a variable cross section that tapers towards the top where the cables anchoring devices are located. It is inclined of 51° from the vertical and it is anchored by means of 2 anchor stays. The bridge is composed of two parts: a reinforced concrete structure with a span of 30 m that overhangs the railway and the composite cable-stayed bridge with a span of 114.725 m. The cross section of the bridge has a constant width of 24 m all over its length. The deck is sub-divided in four vehicle lanes, two in each direction, divided by a central pedestrian lane slightly raised in comparison with the vehicle lanes. There are 40 stays, placed symmetrically in respect to the middle plane of the structure and arranged according to a mixed geometry between an harp and a fan shape to facilitate the positioning of the anchoring devices at the top of the pylon.</p>

Boundary element method in numerical study of three-dimensional Stokes flows in channels of arbitrary shape

2012 ◽  
Vol 9 (1) ◽  
pp. 94-97
Author(s):  
Yu.A. Itkulova
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Cross Section ◽  
Numerical Study ◽  
Three Dimensional ◽  
Cylindrical Tube ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Periodic Flows ◽  
Element Method

In the present work creeping three-dimensional flows of a viscous liquid in a cylindrical tube and a channel of variable cross-section are studied. A qualitative triangulation of the surface of a cylindrical tube, a smoothed and experimental channel of a variable cross section is constructed. The problem is solved numerically using boundary element method in several modifications for a periodic and non-periodic flows. The obtained numerical results are compared with the analytical solution for the Poiseuille flow.

Longitudinal oscillation of a rod with a variable cross section

2019 ◽  
Vol 14 (2) ◽  
pp. 138-141
Author(s):  
I.M. Utyashev
Keyword(s):  
Cross Section ◽  
Natural Frequencies ◽  
Liouville Problem ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Independent Functions ◽  
The Cross ◽  
The Right

Variable cross-section rods are used in many parts and mechanisms. For example, conical rods are widely used in percussion mechanisms. The strength of such parts directly depends on the natural frequencies of longitudinal vibrations. The paper presents a method that allows numerically finding the natural frequencies of longitudinal vibrations of an elastic rod with a variable cross section. This method is based on representing the cross-sectional area as an exponential function of a polynomial of degree n. Based on this idea, it was possible to formulate the Sturm-Liouville problem with boundary conditions of the third kind. The linearly independent functions of the general solution have the form of a power series in the variables x and λ, as a result of which the order of the characteristic equation depends on the choice of the number of terms in the series. The presented approach differs from the works of other authors both in the formulation and in the solution method. In the work, a rod with a rigidly fixed left end is considered, fixing on the right end can be either free, or elastic or rigid. The first three natural frequencies for various cross-sectional profiles are given. From the analysis of the numerical results it follows that in a rigidly fixed rod with thinning in the middle part, the first natural frequency is noticeably higher than that of a conical rod. It is shown that with an increase in the rigidity of fixation at the right end, the natural frequencies increase for all cross section profiles. The results of the study can be used to solve inverse problems of restoring the cross-sectional profile from a finite set of natural frequencies.

scholarly journals Theoretical and Experimental Studies on MEMS Variable Cross-Section Cantilever Beam Based Piezoelectric Vibration Energy Harvester

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 772
Author(s):  
Xianming He ◽  
Dongxiao Li ◽  
Hong Zhou ◽  
Xindan Hui ◽  
Xiaojing Mu
Keyword(s):  
Power Density ◽  
Cantilever Beam ◽  
Cross Section ◽  
Energy Harvester ◽  
Variable Cross Section ◽  
Vibration Energy ◽  
Variable Cross ◽  
Vibration Energy Harvester ◽  
Piezoelectric Vibration Energy Harvester ◽  
Piezoelectric Vibration

The piezoelectric vibration energy harvester (PVEH) based on the variable cross-section cantilever beam (VCSCB) structure has the advantages of uniform axial strain distribution and high output power density, so it has become a research hotspot of the PVEH. However, its electromechanical model needs to be further studied. In this paper, the bidirectional coupled distributed parameter electromechanical model of the MEMS VCSCB based PVEH is constructed, analytically solved, and verified, which laid an important theoretical foundation for structural design and optimization, performance improvement, and output prediction of the PVEH. Based on the constructed model, the output performances of five kinds of VCSCB based PVEHs with different cross-sectional shapes were compared and analyzed. The results show that the PVEH with the concave quadratic beam shape has the best output due to the uniform surface stress distribution. Additionally, the influence of the main structural parameters of the MEMS trapezoidal cantilever beam (TCB) based PVEH on the output performance of the device is theoretically analyzed. Finally, a prototype of the Aluminum Nitride (AlN) TCB based PVEH is designed and developed. The peak open-circuit voltage and normalized power density of the device can reach 5.64 V and 742 μW/cm3/g2, which is in good agreement with the theoretical model value. The prototype has wide application prospects in the power supply of the wireless sensor network node such as the structural health monitoring system and the Internet of Things.

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