Analysis of MDOF Pseudo-Dynamic Test Design of High Flexible Structure

2014 ◽  
Vol 638-640 ◽  
pp. 1781-1784
Author(s):  
Hong Biao Liu ◽  
Qiang Zhang ◽  
Xian Peng Liu
Keyword(s):  
Numerical Simulation ◽  
Dynamic Test ◽  
High Mode ◽  
Flexible Structure ◽  
Test Design ◽  
Base Shear ◽  
Sdof System ◽  
High Rise ◽  
Equivalent Sdof System ◽  
The Impact

In order to point out the main factors in MDOF pseudo-dynamic test design of high-rise flexible, the key points in pseudo-dynamic test design using equivalent MDOF system were analyzed based on the theoretic derivation and numerical simulation, and the problems to notice in test design were pointed out, the pseudo-dynamic test results validity of high piers based on equivalent SDOF system was discussed, and the impact of high mode to the earthquake response of high-rise flexible structure was acquired. The results of numerical simulation of lumped-mass model prove that the contribution of high mode to the displacement of high flexible structure is little, and the displacement is mainly provided by the first-order mode, which is nothing to do with the selection of seismic waves. However, the high mode have great influence on seismic base shear and base moment of high flexible structure, and the influence level is associated with the properties of seismic wave spectrum. Under one specific earthquake wave, the second-order vibration may play a main contribution to seismic base shear and base moment of high-rise flexible structure. Therefore, it is proper to use equivalent two-degree of freedom system in pseudo-dynamic test of high piers. However, if using equivalent SDOF system, the structural displacement response is correct while the strain data and experimental phenomenon may be untrue. The conclusion proposed is significant in guiding the pseudo dynamic test design of high-rise flexible structure and ensuring the rationality of test.

Assessing the effect of night ventilation on PCM performance in high-rise residential buildings

2019 ◽  
Vol 43 (3) ◽  
pp. 229-249 ◽  
Author(s):  
Shahrzad Soudian ◽  
Umberto Berardi
Keyword(s):  
Thermal Energy ◽  
Phase Change Materials ◽  
Positive Impact ◽  
Residential Buildings ◽  
Solidification Rate ◽  
Operative Temperature ◽  
High Rise ◽  
Ventilation Strategies ◽  
Night Ventilation ◽  
The Impact

This article investigates the possibility to enhance the use of latent heat thermal energy storage (LHTES) as an energy retrofit measure by night ventilation strategies. For this scope, phase change materials (PCMs) are integrated into wall and ceiling surfaces of high-rise residential buildings with highly glazed facades that experience high indoor diurnal temperatures. In particular, this article investigates the effect of night ventilation on the performance of the PCMs, namely, the daily discharge of the thermal energy stored by PCMs. Following previous experimental tests that have shown the efficacy of LHTES in temperate climates, a system comprising two PCM layers with melting temperatures selected for a year-around LHTES was considered. To quantify the effectiveness of different night ventilation strategies to enhance the potential of this composite PCM system, simulations in EnergyPlusTM were performed. The ventilation flow rate, set point temperature, and operation period were the main tested parameters. The performance of the PCMs in relation to the variables was evaluated based on indoor operative temperature and cooling energy use variations in Toronto and New York in the summer. The solidification of the PCMs was analyzed based on the amount of night ventilation needed in each climate condition. The results quantify the positive impact of combining PCMs with night ventilation on cooling energy reductions and operative temperature regulation of the following days. In particular, the results indicate higher benefits obtainable with PCMs coupled with night ventilation in the context of Toronto, since this city experiences higher daily temperature fluctuations. The impact of night ventilation design variables on the solidification rate of the PCMs varied based on each parameter leading to different compromises based on the PCM and climate characteristics.

scholarly journals Monitoring the Impact of the Large Building Investments on the Neighborhood

2021 ◽  
Vol 11 (14) ◽  
pp. 6537
Author(s):  
Marian Łupieżowiec
Keyword(s):  
Groundwater Level ◽  
Soil Improvement ◽  
Deep Excavation ◽  
Large Area ◽  
Safety Measures ◽  
High Rise ◽  
The Impact ◽  
Large Building ◽  
Additional Safety ◽  
Made In

The article presents the concept of monitoring buildings and infrastructure elements located near large construction investments (the construction of high-rise buildings of the Oak Terraces housing estate in Katowice and the construction of a tunnel under the roundabout in Katowice along the intercity express road DTŚ). The impacts include deep excavation, lowering of the groundwater level over a large area, and dynamic influences related to the use of impact methods of soil improvement. The presented monitoring includes observation of the groundwater level with the use of piezometers, geodetic measurements of settlement and inclinations, as well as the measurement of vibration amplitudes generated during the works involving shocks and vibrations. It was also important to observe the development of cracks on the basis of a previously made inventory of damage. The results of the monitoring allow corrections to be made in the technology of works (e.g., reduction of vibration amplitudes, application of additional protections at excavations, etc.) or the use additional safety measures. Currently, there are also monitoring systems used during the operation of completed facilities.

Hybrid nanofluid flow over a stretched cylinder with the impact of homogeneous–heterogeneous reactions and Cattaneo–Christov heat flux: Series solution and numerical simulation

Heat Transfer ◽  
2021 ◽  
Author(s):  
Anthonysamy John Christopher ◽  
Nanjundan Magesh ◽  
Ramanahalli Jayadevamurthy Punith Gowda ◽  
Rangaswamy Naveen Kumar ◽  
Ravikumar Shashikala Varun Kumar
Keyword(s):  
Numerical Simulation ◽  
Heat Flux ◽  
Series Solution ◽  
Heterogeneous Reactions ◽  
Hybrid Nanofluid ◽  
Nanofluid Flow ◽  
The Impact

Floating Roof Influence on Seismic Response of Large Vertical Storage Tank

2013 ◽  
Vol 671-674 ◽  
pp. 1399-1402
Author(s):  
Ying Sun ◽  
Jian Gang Sun ◽  
Li Fu Cui
Keyword(s):  
Seismic Response ◽  
Storage Tank ◽  
Numerical Solutions ◽  
Fluid Pressure ◽  
Seismic Intensity ◽  
Site Conditions ◽  
Storage Tanks ◽  
Analysis Model ◽  
Base Shear ◽  
The Impact

To study the impact of floating roof on seismic response of vertical storage tank structure system subjected to seismic excitation, select 150000m3 storage tanks as research object, and the finite element analysis model of storage tanks with and without floating roof were established respectively. The seismic response of these two types of structure in different site conditions and seismic intensity were calculated and the numerical solutions were compared. The results show that floating roof has little impact on base shear and base moment in different site conditions and seismic intensity. Floating roof can effectively reduce the sloshing wave height. The influence of floating roof on dynamic fluid pressure decreases with the increase of seismic intensity, which is less affected by ground conditions.

Investigation on penetration model of shaped charge jet in water

2016 ◽  
Vol 30 (02) ◽  
pp. 1550268 ◽  
Author(s):  
Jinwei Shi ◽  
Xingbai Luo ◽  
Jinming Li ◽  
Jianwei Jiang
Keyword(s):  
Numerical Simulation ◽  
Theoretical Model ◽  
Model Simulation ◽  
Theoretical Models ◽  
Theoretical Research ◽  
Water Medium ◽  
Simulation Results ◽  
Jet Penetration ◽  
The Impact ◽  
Penetration Velocity

To analyze the process of jet penetration in water medium quantitatively, the properties of jet penetration spaced target with water interlayer were studied through test and numerical simulation. Two theoretical models of jet penetration in water were proposed. The theoretical model 1 was established considering the impact of the shock wave, combined with the shock equation Rankine–Hugoniot and the virtual origin calculation method. The theoretical model 2 was obtained by fitting theoretical analysis and numerical simulation results. The effectiveness and universality of the two theoretical models were compared through the numerical simulation results. Both the models can reflect the relationship between the penetration velocity and the penetration distance in water well, and both the deviation and stability of theoretical model 1 are better than 2, the lower penetration velocity, and the larger deviation of the theoretical model 2. Therefore, the theoretical model 1 can reflect the properties of jet penetration in water effectively, and provide the reference of model simulation and theoretical research.

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