scholarly journals Investigations of the Rockfall Impacts on the Flexible Protective Barriers under Seismic Loading

Author(s):  
Ziwei Ge ◽  
Hongyan Liu

Abstract Rockfall triggered by earthquakes can cause severe infrastructure losses and even fatalities. The flexible protective barrier is an efficient rockfall protection system that has been widely used against rockfall. This studyproposed a novel approach to simulate a field test of rockfall impacting the flexible barrier, and the simulation results showed an excellent match with the field test results. Based on this approach, the seismic loading was applied to the numerical model, and four types of seismic loading were adopted, e.g., non-seismic, x-directional seismic, y-directional seismic, and z-directional seismic. This study aims at investigating the dynamic behavior of the flexible protective barrier under different seismic loading during the rockfall impact process. The following findings can be obtained from the simulation results. First of all, the seismic loading can increase the maximum elongation and decrease the final elongation of the flexible protective barrier comparing to non-seismic loading. Second, the largest deformation area of the protective barrier is at the diagonal position when x-directional seismic loading was applied, which is at the vertical bisector position when y-directional and z-directional seismic loading was applied. Third, the maximum elongation of the protective barrier decreased with the increasing seismic wave period. But in general, the amplitude and period of seismic waves have negligible effects on the elongation, maximum normal stress, and maximum shear stress of the flexible protective barrier.

Author(s):  
Supriya Raheja

Background: The extension of CPU schedulers with fuzzy has been ascertained better because of its unique capability of handling imprecise information. Though, other generalized forms of fuzzy can be used which can further extend the performance of the scheduler. Objectives: This paper introduces a novel approach to design an intuitionistic fuzzy inference system for CPU scheduler. Methods: The proposed inference system is implemented with a priority scheduler. The proposed scheduler has the ability to dynamically handle the impreciseness of both priority and estimated execution time. It also makes the system adaptive based on the continuous feedback. The proposed scheduler is also capable enough to schedule the tasks according to dynamically generated priority. To demonstrate the performance of proposed scheduler, a simulation environment has been implemented and the performance of proposed scheduler is compared with the other three baseline schedulers (conventional priority scheduler, fuzzy based priority scheduler and vague based priority scheduler). Results: Proposed scheduler is also compared with the shortest job first CPU scheduler as it is known to be an optimized solution for the schedulers. Conclusion: Simulation results prove the effectiveness and efficiency of intuitionistic fuzzy based priority scheduler. Moreover, it provides optimised results as its results are comparable to the results of shortest job first.


Author(s):  
Lei Si ◽  
Zhongbin Wang ◽  
Xinhua Liu

In order to accurately and conveniently identify the shearer running status, a novel approach based on the integration of rough sets (RS) and improved wavelet neural network (WNN) was proposed. The decision table of RS was discretized through genetic algorithm and the attribution reduction was realized by MIBARK algorithm to simply the samples of WNN. Furthermore, an improved particle swarm optimization algorithm was proposed to optimize the parameters of WNN and the flowchart of proposed approach was designed. Then, a simulation example was provided and some comparisons with other methods were carried out. The simulation results indicated that the proposed approach was feasible and outperforming others. Finally, an industrial application example of mining automation production was demonstrated to verify the effect of proposed system.


2014 ◽  
Vol 70 (7) ◽  
pp. 1285-1291 ◽  
Author(s):  
Jia-jia Deng ◽  
Liang-ming Pan ◽  
De-qi Chen ◽  
Yu-quan Dong ◽  
Cheng-mu Wang ◽  
...  

Aimed at cost saving and pollution reduction, a novel desulfurization wastewater evaporation treatment system (DWETS) for handling wet flue gas desulfurization (WFGD) wastewater of a coal-fired power plant was studied. The system's advantages include simple process, and less investment and space. The feasibility of this system has been proven and the appropriate position and number of nozzles, the spray droplet size and flue gas temperature limitation have been obtained by computational fluid dynamics (CFD) simulation. The simulation results show that a longer duct, smaller diameter and higher flue gas temperature could help to increase the evaporation rate. The optimal DWETS design of Shangdu plant is 100 μm droplet sprayed by two nozzles located at the long duct when the flue gas temperature is 130 °C. Field tests were carried out based on the simulation results. The effects of running DWETS on the downstream devices have been studied. The results show that DWETS has a positive impact on ash removal efficiency and does not have any negative impact on the electrostatic precipitator (ESP), flue gas heat exchanger and WFGD. The pH values of the slurry of WFGD slightly increase when the DWETS is running. The simulation and field test of the DWETS show that it is a feasible future technology for desulfurization wastewater treatment.


Author(s):  
Mohamed B. Trabia ◽  
Woosoon Yim ◽  
Paul Weinacht ◽  
Venkat Mudupu

The objective of this paper is to explore a method for the design of fuzzy logic controller for a smart fin used to control the pitch and yaw attitudes of a subsonic projectile during flight. Piezoelectric actuators are an attractive alternative to hydraulic actuators commonly used in this application due to their simplicity. The proposed cantilever-shaped actuator can be fully enclosed within the hollow fin with one end fixed to the rotation axle of the fin while the other end is pinned at the trailing edge of the fin. The paper includes a dynamic model of the system based on the finite element approach. The model includes external moment due to aerodynamic effects. This paper presents a novel approach for automatically creating fuzzy logic controllers for the fin. This approach uses the inverse dynamics of the smart fin system to determine the ranges of the variables of the controllers. Simulation results show that the proposed controller can successfully drive smart fin under various operating conditions.


2020 ◽  
Vol 17 (6) ◽  
pp. 172988142097046
Author(s):  
Ayan Dutta ◽  
Amitabh Bhattacharya ◽  
O Patrick Kreidl ◽  
Anirban Ghosh ◽  
Prithviraj Dasgupta

We consider the NP-hard problem of multirobot informative path planning in the presence of communication constraints, where the objective is to collect higher amounts of information of an ambient phenomenon. We propose a novel approach that uses continuous region partitioning into Voronoi components to efficiently divide an initially unknown environment among the robots based on newly discovered obstacles enabling improved load balancing between robots. Simulation results show that our proposed approach is successful in reducing the initial imbalance of the robots’ allocated free regions while ensuring close-to-reality spatial modeling within a reasonable amount of time.


Author(s):  
Tiefei Li ◽  
Xueliang Chen ◽  
Zongchao Li

AbstractA three-dimensional multitransmitting formula is developed in ADINA to simulate the input of seismic waves and the scattering of infinite domains at the same time, consistent with the progress of the explicit finite element method of lumped mass. A three-dimensional cube model is built, and a delta pulse wave is input to compare the simulation results with the analytical solutions. The simulation results show that the peak error is 0.2% of the input wave, which meets the requirements of the usual numerical simulation. This method has a certain efficiency advantage in site effect analyses of fine models for localized fields. A velocity structure model of the Yuxi Basin is built, and the associated basin effect is studied by numerical simulation. The distribution of the focusing effect is related to the structure of the narrow east-west and wide north-south features in the Yuxi Basin, and the edge effect is related to the slope of the basin base. A distribution map is given of the amplification effect of ground motion in the basin.


2013 ◽  
Vol 389 ◽  
pp. 618-622 ◽  
Author(s):  
Zhao Jun Tan ◽  
Yao Jin

The field test results show that existing double-pump confluence hydraulic system with constant displacement pump of wheel loader could only save some energy while the load pressure is rather high (>15Mpa in the tests). However, the load pressure is usually low, especially when the wheel Loader is working on bulldozing operation or just steering and running. Thus, an optimized double-pump confluence hydraulic system was designed by adding a proportional valve and adjust operation rule, so that the output oil of steering pump flow into tank by the proportional valve while the load pressure is low and the relative position of joystick is not large (<72%), and in this way the throttle losses is reduced. Simulation results indicate that the optimized confluence hydraulic system could save 26.2% throttle losses while the wheel Loader is working on bulldozing operation.


2012 ◽  
Vol 610-613 ◽  
pp. 2849-2853
Author(s):  
Hong Yin Ou ◽  
Fang Liu ◽  
Qing Long Song ◽  
Long Xing Yu

To improve the low air velocity above the bed areas during the night in hot summer, the reformed plan for the college dormitory fan was presented.The indoor environment was simulated by the software Airpak3.0 to compaire the fan with both no diversion deflector and diversion deflector (the deflector angles are 60°, 120° and 160°) respectively. And a field test was conducted to confirm the simulation results. The results show that the indoor thermal environment above the bed areas has been improved inordinately if adding a deflector with different angles. The air velocity can be increased by 0.15m/s at most when the deflector angle is 160°, yet the airflow displays most evenly with the 120° deflector angle. Meanwhile, the temperature and thermal discomfort have been decreased. The variation of the simulation and measurement values tends to be consistent, so it suggests the fan installing the diversion deflector may improve the thermal environment of college dormitory.


2002 ◽  
Vol 20 (5) ◽  
pp. 390-396 ◽  
Author(s):  
X. Shi ◽  
J. Chen ◽  
H. Yang ◽  
Y. Peng ◽  
X. Ruan

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2601
Author(s):  
Mohammad Reza Salehizadeh ◽  
Mahdi Amidi Koohbijari ◽  
Hassan Nouri ◽  
Akın Taşcıkaraoğlu ◽  
Ozan Erdinç ◽  
...  

Exposure to extreme weather conditions increases power systems’ vulnerability in front of high impact, low probability contingency occurrence. In the post-restructuring years, due to the increasing demand for energy, competition between electricity market players and increasing penetration of renewable resources, the provision of effective resiliency-based approaches has received more attention. In this paper, as the major contribution to current literature, a novel approach is proposed for resiliency improvement in a way that enables power system planners to manage several resilience metrics efficiently in a bi-objective optimization planning model simultaneously. For demonstration purposes, the proposed method is applied for optimal placement of the thyristor controlled series compensator (TCSC). Improvement of all considered resilience metrics regardless of their amount in a multi-criteria decision-making framework is novel in comparison to the other previous TCSC placement approaches. Without loss of generality, the developed resiliency improvement approach is applicable in any power system planning and operation problem. The simulation results on IEEE 30-bus and 118-bus test systems confirm the practicality and effectiveness of the developed approach. Simulation results show that by considering resilience metrics, the performance index, importance of curtailed consumers, congestion management cost, number of curtailed consumers, and amount of load loss are improved by 0.63%, 43.52%, 65.19%, 85.93%, and 85.94%, respectively.


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