Experimental study of the influence of gradation on the dynamic properties of centerline tailings sand

2021 ◽  
Vol 151 ◽  
pp. 106993
Author(s):  
Xin Huang ◽  
Xiaoguang Cai ◽  
Jingshan Bo ◽  
Sihan Li ◽  
Wenhao Qi
1986 ◽  
Vol 51 (6) ◽  
pp. 1259-1267
Author(s):  
Josef Horák ◽  
Petr Beránek

A simulation apparatus for the experimental study of the methods of control of batch reactors is devised. In this apparatus, the production of heat by an exothermic reaction is replaced by electric heating controlled by a computer in a closed loop; the reactor is cooled with an external cooler whose dynamic properties can be varied while keeping the heat exchange area constant. The effect of the cooler geometry on its dynamic properties is investigated and the effect of the cooler inertia on the stability and safety of the on-off temperature control in the unstable pseudostationary state is examined.


2012 ◽  
Vol 446-449 ◽  
pp. 3264-3272 ◽  
Author(s):  
Li Min Sun ◽  
Yi Zhou ◽  
Xue Lian Li

In recent years, structural health monitoring has been paid more and more attention in bridge engineering community. Previous researches showed that ambient temperature was one of principal factors affecting structural modal parameters in long-term. In this paper, an experimental study on correlation between dynamic properties of a cable-stayed bridge and its structural temperature was performed under temperature controlled laboratory environment. Using hammer impacting method, a dynamic testing was conducted based on a steel cable-stayed bridge model which had a span layout of 0.9+1.9+0.9m. During the experiment, the first six vertical bending modes under the environmental temperature of 0, 20 and 40°C were identified with the consideration of three kinds of boundary conditions at the deck’s ends as to two degrees of freedom, i.e. the longitudinal translation (UX) and the rotation about the transverse beam (RotZ). The above boundary conditions are UX & RotZ not constrained, UX constrained only and UX & RotZ constrained, attempting to simulate the different conditions of the bridge expansion joints. The efforts were paid to explain the physical mechanism of the results based on the updated FE model. This experimental study indicates a tendency that the frequency of the cable-stayed bridge model decreases with the increase of temperature. And furthermore, the relative difference of frequencies between 0 and 40 °C is affected by boundary conditions; in other words, when the deck is free to expand, the variation of model’s frequencies is smaller than that when the deck is restrained to expand, which is similar to the condition of the bridge’s expansion joints cannot work as normal. This experimental study can give some reference to the research of SHM and damage identification for cable-stayed bridges.


Author(s):  
Kenichi MACHIDA ◽  
Makoto WATAHIKI ◽  
Yoshimitsu OHASHI ◽  
Isao SAKAMOTO

2018 ◽  
Vol 153 (3) ◽  
pp. 032014
Author(s):  
Xiao Jin ◽  
Li Hui ◽  
Zhang Shanjun ◽  
Jiang Ningshan ◽  
Ma Yanya

2012 ◽  
Vol 12 (11) ◽  
pp. 3441-3454 ◽  
Author(s):  
N. Ahmad ◽  
Q. Ali ◽  
M. Ashraf ◽  
B. Alam ◽  
A. Naeem

Abstract. Half-Dressed rubble stone (DS) masonry structures as found in the Himalayan region are investigated using experimental and analytical studies. The experimental study included a shake table test on a one-third scaled structural model, a representative of DS masonry structure employed for public critical facilities, e.g. school buildings, offices, health care units, etc. The aim of the experimental study was to understand the damage mechanism of the model, develop damage scale towards deformation-based assessment and retrieve the lateral force-deformation response of the model besides its elastic dynamic properties, i.e. fundamental vibration period and elastic damping. The analytical study included fragility analysis of building prototypes using a fully probabilistic nonlinear dynamic method. The prototypes are designed as SDOF systems assigned with lateral, force-deformation constitutive law (obtained experimentally). Uncertainties in the constitutive law, i.e. lateral stiffness, strength and deformation limits, are considered through random Monte Carlo simulation. Fifty prototype buildings are analyzed using a suite of ten natural accelerograms and an incremental dynamic analysis technique. Fragility and vulnerability functions are derived for the damageability assessment of structures, economic loss and casualty estimation during an earthquake given the ground shaking intensity, essential within the context of risk assessment of existing stock aiming towards risk mitigation and disaster risk reduction.


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