The Anti-Bending Performance Study of Loaded Continuous Beam that Strengthened with Prestressed Laterally Bonded Carbon Fiber Sheets

2014 ◽  
Vol 541-542 ◽  
pp. 283-287
Author(s):  
Xiang Rong Zeng ◽  
Cai Ping Li ◽  
Jin Chen ◽  
Xiao Xie ◽  
Lei Zhang
Keyword(s):  
Carbon Fiber ◽  
Continuous Beam ◽  
Reinforcement Effect ◽  
Performance Study ◽  
Bending Performance ◽  
Continuous Beams ◽  
Initial Load ◽  
Stress And Deformation ◽  
Better Than

We studied the strengthening performance of prestressed laterally bonded carbon fiber sheets (CFS) to two-span continuous beams in this paper, which included one unstrengthened beam, two non-prestressed laterally bonded CFS strengthening beams, and four prestressed laterally bonded CFS strengthening beams, and all of them were sticked with CFS on different styles on tension part of lateral beam. We discussed the stress and deformation of laterally bonded CFS strengthened continuous beams under different initial load cases and different prestressed impact, and studied the influence of initial load and prestressing to reinforcement effect. The results showed that the size of initial load and prestressing would affect the reinforcement effect of laterally bonded CFS to continuous beams; The smaller initial load, the better reinforcement effect; The reinforcement effect to continuous beams of prestressed laterally bonded CFS was better than the non-prestressed laterally bonded CFS. Corresponding to latter, the former also owned better deformation performance, less cracks number and width.

scholarly journals Application of Laplace Transform to the Free Vibration of Continuous Beams

2017 ◽  
Vol 63 (1) ◽  
pp. 163-180 ◽  
Author(s):  
H.B. Wen ◽  
T. Zeng ◽  
G.Z. Hu
Keyword(s):  
Free Vibration ◽  
Laplace Transform ◽  
Reaction Force ◽  
Bending Moment ◽  
Frequency Equation ◽  
Simplified Model ◽  
Continuous Beam ◽  
Transform Method ◽  
Continuous Beams ◽  
Vibration Problems

AbstractLaplace Transform is often used in solving the free vibration problems of structural beams. In existing research, there are two types of simplified models of continuous beam placement. The first is to regard the continuous beam as a single-span beam, the middle bearing of which is replaced by the bearing reaction force; the second is to divide the continuous beam into several simply supported beams, with the bending moment of the continuous beam at the middle bearing considered as the external force. Research shows that the second simplified model is incorrect, and the frequency equation derived from the first simplified model contains multiple expressions which might not be equivalent to each other. This paper specifies the application method of Laplace Transform in solving the free vibration problems of continuous beams, having great significance in the proper use of the transform method.

scholarly journals Effect of intermediate supports location on natural frequencies of multiple cracked continuous beams

2018 ◽  
Author(s):  
Do Nam ◽  
Nguyen Tien Khiem ◽  
Le Khanh Toan ◽  
Nguyen Thi Thao ◽  
Pham Thi Ba Lien
Keyword(s):  
General Solution ◽  
Free Vibration ◽  
Natural Frequencies ◽  
Continuous Beam ◽  
Cracked Beam ◽  
Continuous Beams ◽  
Simplified Method ◽  
Rigid Supports ◽  
Natural Frequency Analysis ◽  
Eigenfrequency Spectrum

The present paper deals with free vibration of multiple cracked continuous beams with intermediate rigid supports. A simplified method is proposed to obtain general solution of free vibration in cracked beam with intermediate supports that is then used for natural frequency analysis of the beam in dependence upon cracks and support locations. Numerical results show that the support location or ratio of span lengths in combination with cracks makes a significant effect on eigenfrequency spectrum of beam. The discovered effects of support locations on eigenfrequency spectrum of cracked continuous beam are useful for detecting not only cracks but also positions of vanishing deflection on the beam.

scholarly journals Appropriate Matching Locations of Rail Expansion Regulator and Fixed Bearing of Continuous Beam Considering the Temperature Change of Bridge

2020 ◽  
Vol 10 (17) ◽  
pp. 6046
Author(s):  
Ping Lou ◽  
Te Li ◽  
Xinde Huang ◽  
Ganggui Huang ◽  
Bin Yan
Keyword(s):  
Temperature Change ◽  
Element Model ◽  
Continuous Beam ◽  
Fixed Bearing ◽  
Effective Measure ◽  
Long Span ◽  
Continuous Beams ◽  
Additional Force ◽  
Continuously Welded Rail ◽  
Nonlinear Finite Element Model

Due to the temperature change of bridges, there is a great additional force in continuously welded rails on continuous bridges. Laying rail expansion regulators is an effective measure to reduce the additional force. The nonlinear finite element model is presented for a continuously welded rail track with a rail expansion regulator resting on the embankment and simple and continuous beams, considering the temperature change of the bridge. Then, a method is proposed to determine the locations of the rail expansion regulator and the fixed bearing of the continuous beam, corresponding to the maximum additional forces of rail reaching minimum values. Their appropriate matching locations are recommended based on the obtained influence laws of any locations of the rail expansion regulator and the fixed bearing of the continuous beam on the maximum additional forces of rail. The results can provide the theoretical basis for the design of the rail expansion regulator and the fixed bearing of long-span continuous bridges.

scholarly journals A Performance Study of Some Approximation Algorithms for Computing a Small Dominating Set in a Graph

Algorithms ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 339
Author(s):  
Jonathan Li ◽  
Rohan Potru ◽  
Farhad Shahrokhi
Keyword(s):  
Approximation Algorithms ◽  
Real World ◽  
Hybrid Algorithm ◽  
Dominating Set ◽  
Performance Ratio ◽  
Performance Study ◽  
Similar Time ◽  
Sparse Graphs ◽  
Lp Rounding ◽  
Better Than

We implement and test the performances of several approximation algorithms for computing the minimum dominating set of a graph. These algorithms are the standard greedy algorithm, the recent Linear programming (LP) rounding algorithms and a hybrid algorithm that we design by combining the greedy and LP rounding algorithms. Over the range of test data, all algorithms perform better than anticipated in theory, and have small performance ratios, measured as the size of output divided by the LP objective lower bound. However, each have advantages over the others. For instance, LP rounding algorithm normally outperforms the other algorithms on sparse real-world graphs. On a graph with 400,000+ vertices, LP rounding took less than 15 s of CPU time to generate a solution with performance ratio 1.011, while the greedy and hybrid algorithms generated solutions of performance ratio 1.12 in similar time. For synthetic graphs, the hybrid algorithm normally outperforms the others, whereas for hypercubes and k-Queens graphs, greedy outperforms the rest. Another advantage of the hybrid algorithm is to solve very large problems that are suitable for application of LP rounding (sparse graphs) but LP formulations become formidable in practice and LP solvers crash, as we observed on a real-world graph with 7.7 million+ vertices and a planar graph on 1,000,000 vertices.

Adsorption Performance Study of Atrazine onto Activated Carbon Fiber

2013 ◽  
Vol 807-809 ◽  
pp. 1343-1346
Author(s):  
Yi Fan Li ◽  
Ying Liu ◽  
Hou Qi Liu ◽  
Li Li
Keyword(s):  
Activated Carbon ◽  
Carbon Fiber ◽  
Ph Value ◽  
Activated Carbon Fiber ◽  
Adsorption Rate ◽  
Solution Temperature ◽  
Performance Study ◽  
Initial Concentration ◽  
Adsorption Condition ◽  
Optimum Ph

The research used activated carbon fiber (ACF) as adsorbent to remove atrazine, a kind of herbicide. It set a series of static adsorption experiments under different solution temperature, pH value and initial concentration to get a optimum adsorption condition. The experiment shows that the optimum pH for the removal of atrazine is 7. The adsorption rate is highest at 20°C. The adsorption rate decreases while the initial concentration increases.

The Study of the Flexural Capacity of Old and New Prestressed Concrete Hollow Slab Strengthened with CFRP

2013 ◽  
Vol 482 ◽  
pp. 66-69
Author(s):  
Bin Jia ◽  
Lei Fu ◽  
Yu Zhang ◽  
Yi Lu
Keyword(s):  
Experimental Study ◽  
Carbon Fiber ◽  
Engineering Design ◽  
Prestressed Concrete ◽  
Reinforcement Effect ◽  
Flexural Capacity ◽  
Design Specifications ◽  
Secondary Load ◽  
Contrast Analysis ◽  
Load Conditions

Prestressed hollow slab strengthened with CFRP is a new reinforcement method. To study the effect on reinforcement through different carbon fiber paste volume and paste manner, we did the experimental study on flexural capacity under the secondary load conditions with prestressed concrete hollow slab commonly used in engineering. Meanwhile, we also did the contrast analysis of reinforcement effect on the old and new prestressed concrete hollow slab. The results showed that prestressed concrete hollow slab strengthened with CFRP could effectively improve the flexural capacity of the specimen, besides the capacity increasing of the old and new prestressed hollow slab is a little difference, but both of the new and old can meet the engineering design specifications.

scholarly journals Experimental Limiting Factors for the Search of μ→eγ at Future Facilities

Universe ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 27
Author(s):  
Francesco Renga ◽  
Gianluca Cavoto ◽  
Angela Papa ◽  
Emanuele Ripiccini ◽  
Cecilia Voena
Keyword(s):  
Beam Intensity ◽  
Limiting Factors ◽  
Continuous Beam ◽  
Lepton Flavor ◽  
Continuous Beams

The search for the Lepton Flavor Violating decay μ → e γ exploits the most intense continuous muon beams, which can currently deliver ∼ 10 8 muons per second. In the next decade, accelerator upgrades are expected in various facilities, making it feasible to have continuous beams with an intensity of 10 9 or even 10 10 muons per second. We investigate the experimental limiting factors that will define the ultimate performances, and hence the sensitivity, in the search for μ → e γ with a continuous beam at these extremely high rates. We then consider some conceptual detector designs and evaluate the corresponding sensitivity as a function of the beam intensity.

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