From the perspective of microscopic mechanism to study the origin and the macroscopic behavior of the magnetic viscosity characteristics need to discuss the magnetic viscosity effects of the magnetic fluid dynamics, and the magnetic viscous forces in the magnetic fluid dynamics equations is the root cause of the magnetic viscosity effects. In the paper, the common expressions of first-order viscous force and quatratic viscous force of the magnetic fluid are derived from combining the magnetic fluid viscosity expression forms under different concentrations together, while based on the molecular circulation theory and electromagnetic dynamics principle, the quatratic magnetic viscous force model of magnetic fluid is derived from the basic relationship between the magnetic relaxation process. Furthermore the coefficient correction model of the quatratic viscous force is given when the solid particles of magnetic fluid present the formation of chain. Finally it shows the magnetic fluid viscous force model and a clear description of the external magnetic field influence on the magnetic fluid viscosity changes.
This paper built the two-dimension equivalent model of mega-sub controlled structure system (MSCSS) and mega frame structure, make an analysis of elastic-plastic time history with the different seismic records of observed data. The research of displacement, acceleration and distribution of plastic hinges obtained by the test can illustrate the controlling characteristics of these two structures. The results show that within the elastic-plastic state, mega-sub controlled structural system still have good response control effect; the control effectiveness of the mega frame and sub-structures of the MSCSS is better than that of the mega frame structures.
The randomness of value of tuned sub-structure mass and rigidity is comparatively large because of the needs of actual projects. Based on the dynamic characteristics and reliability of MSCS, the seismic response of the mega structure and the overall failure probability are discussed with the value of tuned sub structural mass and rigidity under different seismic intensity. It is shown that tuned sub structural mass and rigidity have significant affection on the overall reliability of structure, and seismic intensity has not interfere this regular pattern. Therefore, structural parameters of optimization which are referred to the regular pattern should be considered in the actual design in order to further enhance seismic capability of MSCS.
This study evaluates the influence of an extensive green roof on runoff quantity dynamic during individual rainstorms in Central China. Controlled experiments on a simulated extensive green-roof plot were carried out firstly to produce a unit hydrograph (UH) by the methods of S-curve linearization treatment and curve fitting. Then in situ tests were conducted to compare runoff quantity per minute from the green roof plot and a conventional roof plot to verify the obtained UH and compare their runoff quantity dynamic during two rain storms in the year of 2009.The obtained UH is able to predict accurately peak flows and runoff volumes for any rain input. When the initial water content of the substrate was dry, the 7 cm thick green roof can delay the runoff initiating for nearly 8 minutes, lower runoff peak and volume by about 50% compared with conventional roof during a 10.1mm rainstorm on 7 June; and even when the substrate was wet, the extensive green roof can detain runoff effectively by 129 min longer than conventional roof and thus lower the peak flow of runoff by 43% during a 6.3 mm rainstorm on 12 March.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.