scholarly journals Preliminary Design and Experimental Study of a Steel-Batten Ribbed Cable Dome

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2136
Author(s):  
Mingmin Ding ◽  
Yuzhou Shen ◽  
Yang Wei ◽  
Bin Luo ◽  
Lulu Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Internal Force ◽  
Force Balance ◽  
Test Model ◽  
Uniform Load ◽  
Bending Stresses ◽  
Internal Forces ◽  
Cable Dome ◽  
Loaded Area

A steel-batten ribbed cable dome structural system is proposed. By replacing the upper flexible cables with semi-rigid steel battens, rigid roofing materials were conveniently installed overhead via non-bracket or less-bracket technology. Additionally, an 8 m diameter test model was designed, and a ‘ω’ shaped less-bracket consequent hoist-dragging system was adopted. Finally, the test model was tested under symmetric and asymmetric uniform loading arrangements, while a finite element model was established to verify the test values. The results indicate that the measured values are basically consistent with the finite element values. In the early steps of hoisting and dragging, the structure establishes a prestress, accumulates stiffness, and found its internal force balance, while the entire structure keeps a “ω” shape to guarantee stability. As the internal forces of the components increase, the structure turns from “ω” to “m” and finally reached its designed shape. With increasing symmetric uniform load, the internal forces of the cables decrease, the bending stresses of the steel battens increase, and the steel battens remain in the elastic stage. Under an asymmetric uniform load, the high loaded area is displaced downward, and the low loaded area behaves upward, twisting the overall structure.

scholarly journals Experimental Investigation and Numerical Simulation of a Levy Hinged-Beam Cable Dome

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 110
Author(s):  
Mingmin Ding ◽  
Bin Luo ◽  
Shuyao Ding ◽  
Yuzhou Shen ◽  
Lifan Huang
Keyword(s):  
Internal Force ◽  
Force Balance ◽  
Entire Structure ◽  
Upward Deflection ◽  
Bending Stresses ◽  
Structural Configurations ◽  
Experimental Values ◽  
Cable Dome ◽  
Hinged Beams ◽  
Local Deformations

According to existing rigid roofing projects, a new structure called the Levy hinged-beam cable dome is proposed. By replacing the upper flexible cables with hinged beams, rigid plates can be installed overhead. To fulfill the requirements of integral tow-lifting construction, the setting criteria for the temporary hinged joints on ridge beams were presented. An 8-m diameter specimen was manufactured and monitored to investigate the structural configurations during the accumulative traction-hoisting construction process. Finally, the specimen was tested under full-span and half-span loading conditions, while a numerical model was built to verify the experimental values. The results show that in the early stages of traction-hoisting, the structure establishes the overall prestress and finds its internal force balance, while the entire structure is in a shape of “ω”. As the component’s internal force increases during the construction steps, and the local deformations of the hinged beams gradually decrease, with the entire structure changing from “ω” to “m”, and finally reach their designed states. Under full-span loads, large local deformations occurred at the HB-3 hinges, while the bending stresses of these hinged beams were relatively small. Under half-span loads, the loading part exhibits a downward appearance, while the unloading part exhibits upward deflection.

Design of Static Test Model for Three-Tower Cable-Stayed Self-Anchored Suspension Composed Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 1528-1535
Author(s):  
Yu Zhao ◽  
Yong Jun Zhou ◽  
Jing Sun ◽  
Jin Tao Tang ◽  
Xu Li
Keyword(s):  
Complex System ◽  
Finite Element ◽  
Element Model ◽  
Test Model ◽  
Test Results ◽  
Static Test ◽  
Whole Process ◽  
Aesthetic Appearance ◽  
Load Carrying ◽  
Novel Structures

Cable-stayed self-anchored suspension composed bridges have novel structures and aesthetic appearance with complex system and difficulty for design and construction. In order to acquire a better knowledge of the load-carrying capability of this type of bridges, based on a real bridge and the theory of abnormal similarity, a full-bridge scaled down(1:20) test model was built to simulate the whole process of construction. The test results were preferably fit the theoretical calculation value. It can be seen that the design of the bridge was reasonable, and the accuracy of the calculation of finite element model was verified at the same time. The test and the related results can be used as the reference for the test and design of the similar bridges.

scholarly journals A Novel Method for Tooth Bending Stress Calculation of Gears With Asymmetric Teeth

2021 ◽  
Author(s):  
Oguz DOGAN ◽  
Celalettin YUCE ◽  
Fatih KARPAT
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Experimental Studies ◽  
Element Model ◽  
Bending Stress ◽  
Element Analysis ◽  
Stress Calculation ◽  
Bending Stresses ◽  
New Equation ◽  
Asymmetric Factor

Abstract Today, gear designs with asymmetric tooth profiles offer essential solutions in reducing tooth root stresses of gears. Although numerical, analytical, and experimental studies are carried out to calculate the bending stresses in gears with asymmetric tooth profiles a standard or a simplified equation or empirical statement has not been encountered in the literature. In this study, a novel bending stress calculation procedure for gears with asymmetric tooth profiles is developed using both the DIN3990 standard and the finite element method. The bending stresses of gears with symmetrical profile were determined by the developed finite element model and was verified by comparing the results with the DIN 3990 standard. Using the verified finite element model, by changing the drive side pressure angle between 20° and 30° and the number of teeth between 18 and 100, 66 different cases were examined and the bending stresses in gears with asymmetric profile were determined. As a result of the analysis, a new asymmetric factor was derived. By adding the obtained asymmetric factor to the DIN 3390 formula, a new equation has been derived to be used in tooth bending stresses of gears with asymmetric profile. Thanks to this equation, designers will be able to calculate tooth bending stresses with high precision in gears with asymmetric tooth profile without the need for finite element analysis.

The Performance of Steel Beam during the Cooling Phase and the Impact of Fire Parameters

2013 ◽  
Vol 404 ◽  
pp. 232-236
Author(s):  
Xiu Ying Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Solid Model ◽  
Steel Beam ◽  
Uniform Load ◽  
Cooling Process ◽  
Internal Forces ◽  
Cooling Phase ◽  
The Impact ◽  
Temperature Heating

In order to study the performance of steel beam in the cooling process, a series of numerical analysis has been carried out in this paper. The solid model of the beam was established firstly using finite element method, the beam was heated and cooled gradually under the certain uniform load, then the internal forces and deformation of the beam were analyzed in the whole fire process. Based on this, the parameters of the highest temperature, heating rate and the cooling rate were changed, and their affect on the beam performance was studied by comparing.

Full-Scale Test and Numerical Simulation of Guided Flexible Protection System under a Blasting Load

2020 ◽  
Vol 26 (2) ◽  
pp. 243-256
Author(s):  
Xin Qi ◽  
Hu Xu ◽  
Zhixiang Yu ◽  
Keqin Sun ◽  
Shichun Zhao
Keyword(s):  
Element Model ◽  
Internal Force ◽  
Full Scale ◽  
Protection System ◽  
Dissipated Energy ◽  
Full Scale Test ◽  
Internal Forces ◽  
Scale Test ◽  
Stage Process ◽  
Blasting Load

ABSTRACT Both active and passive flexible protection methods are effective against rockfalls, but they can result in a secondary hazard due to cumulate rocks inside the structure. To solve this problem, guided flexible protection systems are receiving increased attention in the engineering community. In this study, a full-scale test of a guided flexible protection system was carried out, where the bottom of the mesh was anchored under a blasting load, which can be considered as an extreme loading event related to rockfall hazards. The fluid-solid coupling method was employed in a finite element model to simulate the entire process from the blast to the accumulation of rocks at the bottom of the slope. Based on the experimental and numerical results, a two-stage process was revealed, the internal force and the dissipated energy of each component were compared and analyzed, and the load-transferring path within the system was obtained. The internal forces of the support ropes reached their maximum values in the intercept stage. The posts experienced two peak values, the first of which, in the guide stage, was twice that in the intercept stage. The brake rings were the main energy-dissipating components, and the energy dissipation in the intercept stage was much greater than that in the guide stage. Furthermore, the interaction in terms of collision and friction between the rocks, the slope, and the system was not insignificant, particularly in the guide stage, which can account for more than 40 percent of the consumed energy of the rockfall.

scholarly journals Research on Biomimetic Models and Nanomechanical Behaviour of Membranous Wings of Chinese Bee Apis cerana cerana Fabricius

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Yanru Zhao ◽  
Dongsheng Wang ◽  
Jin Tong ◽  
Jiyu Sun ◽  
Jin Zhang
Keyword(s):  
Finite Element ◽  
Apis Cerana ◽  
Element Model ◽  
Apis Cerana Cerana ◽  
Technical Innovation ◽  
Uniform Load ◽  
Load Bearing Capacity ◽  
Concentrated Force ◽  
Stress States ◽  
The Finite Element Model

The structures combining the veins and membranes of membranous wings of the Chinese bee Apis cerana cerana Fabricius into a whole have excellent load-resisting capacity. The membranous wings of Chinese bees were taken as research objects and the mechanical properties of a biomimetic model of membranous wings as targets. In order to understand and learn from the biosystem and then make technical innovation, the membranous wings of Chinese bees were simulated and analysed with reverse engineering and finite element method. The deformations and stress states of the finite element model of membranous wings were researched under the concentrated force, uniform load, and torque. It was found that the whole model deforms evenly and there are no unusual deformations arising. The displacements and deformations are small and transform uniformly. It was indicated that the veins and membranes combine well into a whole to transmit loads effectively, which illustrates the membranous wings of Chinese bees having excellent integral mechanical behaviour and structure stiffness. The realization of structure models of the membranous wings of Chinese bees and analysis of the relativity of structures and performances or functions will provide an inspiration for designing biomimetic thin-film materials with superior load-bearing capacity.

Random Vibration Analysis of a Printed Wiring Board with Electronic Components

1991 ◽  
Vol 34 (1) ◽  
pp. 25-31
Author(s):  
Jack Roberts ◽  
Debra Stillo
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Random Vibration ◽  
Element Model ◽  
Printed Wiring Board ◽  
Electronic Components ◽  
Bending Stresses ◽  
Wiring Board ◽  
Element Technique ◽  
The Finite Element Model

A printed wiring board (PWB) with electronic components has been modeled using the finite element technique and compared with the same PWB experimentally tested in a chassis during a 2 hr random vibration test. Accelerometers were attached to the PWB in locations where nodes existed in the finite element model (FEM). The FEM predicted the first natural frequency to within 10 percent of the test results. Due to wedge locks that loosened during the test, the PWB accelerations in the finite element model and the test differed by as much as 40 percent. The ceramic capacitor on the PWB was modeled in detail with leads attached to the PWB to examine bending stresses in the leads. During the 2 hr test there were no failures for those leads with adequate solder joints. A failure did occur, however, on a lead with insufficient solder. A fatigue analysis of the FEM lead bending stresses indicated lead failure if no solder was used, whereas no failures were predicted for properly soldered leads.

Influence of Cable Dampers on Cable-Stayed Bridges

2012 ◽  
Vol 256-259 ◽  
pp. 1474-1479
Author(s):  
Dong Liang ◽  
Hui Cai Shen ◽  
Yan Feng Li
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Test Model ◽  
Cable Stayed Bridge ◽  
Modal Damping ◽  
Mode Method ◽  
Practical Model ◽  
The Relationship ◽  
Theoretical Results ◽  
Cable Stayed Bridges

Cable-stayed bridges have seen a wider application in recent years, with many having longer and longer spans. Modern cable-stayed bridges are using numerous cables to support the stiffing girders. Many cable dampers are installed to mitigate cable vibration. This paper focuses the attention on the effect of cable damper on the dynamic characteristics of the whole cable-stayed bridge, especially the modal damping. A practical model comprised of the cable, girder, and damper is developed to analyze the relationship between system modal damping and the performance of cable damper with complex mode method. A test model with cable, girder and damper was made to verify the theoretical results. A finite element model of a simplified cable-stayed bridge based on test model is adopted to assess the effects of cable dampers on the anti-seismic performance and wind-resistant behavior of the cable-stayed bridge. The results show that the cable dampers of cable-stayed bridge can increase the modal damping of the whole bridge.

Precision Machines: Diagnostics of Vibration Through Modal and Finite Element Analysis

1991 ◽  
Author(s):  
V. Prakash ◽  
R. J. Montague
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Test Model ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Structure Correlation ◽  
Three Dimensional Finite Element ◽  
Precision Machines

Abstract This paper presents the diagnostics of the effects of vibration on the precise placement of electronic components in a surface mount assembly process. Experimental Modal Analysis using present day software/hardware as well as a three dimensional finite element model are performed on the machine structure. Correlation between the experiment and finite element model are also performed and the strength of using the finite element model as a test model for contemplating any design alterations are presented.

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