Algorithm-aided structural-optimization strategies for the design of variable cross-section beams

2021 ◽  
Author(s):  
Laura Sardone ◽  
Alessandra Fiore ◽  
Rita Greco ◽  
Carlo Moccia ◽  
Nikos D. Lagaros ◽  
...  
Keyword(s):  
Structural Optimization ◽  
Cross Section ◽  
Variable Cross Section ◽  
Variable Cross

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.

Solar Concentrator Structural Optimization: A Variable Beam Cross Section Design

2017 ◽  
Author(s):  
Moucun Yang ◽  
Yuezhao Zhu ◽  
Wei Fu ◽  
Garth Pearce ◽  
Robert A. Taylor
Keyword(s):  
Structural Optimization ◽  
Cross Section ◽  
Cost Savings ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Maximum Displacement ◽  
Cross Sectional ◽  
Optical Efficiency ◽  
Box Structure ◽  
Section Design

The design and construction of solar concentrators heavily affects their cost, heat utilization and optical efficiency. Current trough concentrators support the reflector with an equivalent uniform beam configured from a metal grid sub-structure. Under gravity and wind loads, the support-structure stress distribution varies as a function of position of the structure and the tracking angle. In the conventional design, there is ample surplus stiffness and strength designed into some beams of the structure, which increases the overall weight and cost of the structure. This paper describes an approach towards structural optimization of trough concentrators (with the Eurotrough design taken as an example, that means that the safety factors and structure is similar with Eurotrough design) using a variable cross section beam. The main improvement of this approach comes from keeping the beams rigid and strong near the two ends (at the torque box structure) while allowing the middle of the structure to be relatively weak. Reducing the cross-sectional area of the central beams not only reduces amount of material needed for the structure but also reduces the deflection of the reflector. The simulated results show that the concentrator’s structural weight (including the torque box, endplates and cantilever arms) and the maximum displacement of the reflector are reduced about 15.3% (about 151.2kg per 12-metre long element) and 15.5%, respectively. This represents a meaningful capital and installation cost savings while at the same time improving the optical efficiency.

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.

Sign in / Sign up

Export Citation Format

Share Document