scholarly journals Study of Lead Rubber Bearings for Vibration Reduction in High-Tech Factories

2020 ◽  
Vol 10 (4) ◽  
pp. 1502 ◽  
Author(s):  
Shen-Haw Ju ◽  
Cheng-Chun Yuantien ◽  
Wen-Ko Hsieh

This paper studies the seismic and micro vibrations of the high-tech factory with and without lead rubber bearings (LRBs) using the three-dimensional (3D) finite element analysis. The soil-structure interaction is included using the p-y, t-z, and Q-z nonlinear soil springs, while the time-history analysis is performed under seismic, wind, or moving crane loads. The finite element results indicate that the moving crane does not change the major ambient vibrations of the factory with and without LRBs. For a normal design of LRBs, the high-tech factory with LRBs can decrease the seismic base shear efficiently but will have a much larger wind-induced vibration than that without LRBs, especially for the reinforced concrete level. Because micro-vibration is a major concern for high-tech factories, one should use LRBs with a large initial stiffness to resist wind loads, and use a small final LRB stiffness to reduce the seismic load of high-tech factories. This situation may make it difficult to obtain a suitable LRB, but it is an opportunity to reduce the seismic response without increasing the micro-vibration of high-tech factories.

2014 ◽  
Vol 711 ◽  
pp. 82-85
Author(s):  
You Jia Zhang

In order to research the prestressed concrete containment structure under Strong Earthquake, the multi-layer shell elements has been used to set up 3-d finite element model , time history and the static nonlinear analysis is carried out on the structure. Nonlinear finite element of a 1/10-scale PCCV model was analyzed and the dynamic characteristics of the model, the initial stiffness, the maximum base shear and the maximal displacement on the top of the cylinder had been calculated. Research show when ground motion reached 3g, tensile stress of concrete on wall and equipment at the bottom of the valve hole have exceeded 4MPa, but tensile stress of concrete on dome have less than 0.5MPa. The finite model calculated results are in good agreement with the results of previous papers of Pseudo dynamic test. It is concluded that this containment vessel has sufficient aseismic safety. It can provide a reference for seismic design.


2020 ◽  
Vol 26 (19-20) ◽  
pp. 1646-1655
Author(s):  
Shen-Haw Ju

This study investigates the derailment of trains moving on bridges with lead rubber bearings. A moving wheel/rail axis element that couples two wheels and rails together is first developed to generate a train finite element model with 12 cars, while the sliding, sticking, and separation modes of the wheels and rails are accurately simulated. The finite element results indicate that the base shear of the bridge with lead rubber bearings is much smaller than that without lead rubber bearings. Similar to the base shear, the train derailment coefficients for the bridge with lead rubber bearings are much smaller than those without lead rubber bearings because yield lead rubber bearings during large seismic loads can change the bridge natural frequency to avoid resonance. For earthquakes with a very long dominant period, the lead rubber bearing effect to reduce the train derailment may not be obvious because the natural period of the bridge due to the full yield of lead rubber bearings can approach the dominant period of the earthquake.


2019 ◽  
Vol 2019 (0) ◽  
pp. D41
Author(s):  
Takahiro MORI ◽  
Nobuo MASAKI ◽  
Yu SAKURAI ◽  
Tomokazu HIGUCHI ◽  
Tadashi MUROFUSHI ◽  
...  

2014 ◽  
Vol 1065-1069 ◽  
pp. 19-22
Author(s):  
Zhen Feng Wang ◽  
Ke Sheng Ma

Based on ABAQUS finite element analysis software simulation, the finite element model for dynamic analysis of rigid pile composite foundation and superstructure interaction system is established, which selects the two kinds of models, by simulating the soil dynamic constitutive model, selecting appropriate artificial boundary.The influence of rigid pile composite foundation on balance and imbalance of varying rigidity is analyzed under seismic loads. The result shows that the maximum bending moment and the horizontal displacement of the long pile is much greater than that of the short pile under seismic loads, the long pile of bending moment is larger in the position of stiffness change. By constrast, under the same economic condition, the aseismic performance of of rigid pile composite foundation on balance of varying rigidity is better than that of rigid pile composite foundation on imbalance of varying rigidity.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Gaosheng Wang ◽  
Yunhou Sun ◽  
Ao Zhang ◽  
Lei Zheng ◽  
Yuzheng Lv ◽  
...  

Based on experiments and finite element analysis, the impact resistance of metal flexible net was studied, which can provide reference for the application of metal flexible net in rock fall protection. The oblique (30 degrees) impact experiment of metal flexible net was carried out, the corresponding finite element (FE) to the experiment was established, and the FE model was verified by simulation results to the experimental tests from three aspects: the deformation characteristics of metal flexible net, the time history curves of impact force on supporting ropes, and the maximum instantaneous impact force on supporting ropes. The FE models of metal flexible nets with inclination angles of 0, 15, 30, 45, 60, and 75 degrees were established, and the impact resistance of metal flexible nets with different inclination angles was analyzed. The research shows that the metal flexible net with proper inclination can bounce the impact rock fall out of the safe area and prevent rock fall falling on the metal flexible net, thus realizing the self-cleaning function. When the inclination angle of the metal flexible net is 15, 30, and 45 degrees, respectively, the bounce effect after impact is better, the remaining height is improved, the protection width is improved obviously, and the impact force is reduced. Herein, the impact force of rock fall decreases most obviously at 45 degrees inclination, and the protective performance is relatively good.


2010 ◽  
Vol 163-167 ◽  
pp. 327-331 ◽  
Author(s):  
Liang Zheng ◽  
Zhi Hua Chen

Finite element model of both the single-layer Schwedler reticulated dome with the span of 50m and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. PLASTIC_KINEMATIC (MAT_003) material model which takes stain rate into account was used to simulate steel under impact load. The automatic point to surface contact (NODES TO SURFACE) was applied between the dome and impact block. Three stages of time history curve of the impact force on the apex of the single-layer Scheduler reticulated dome including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. It must be pointed out that the peak of the impact force of the single-layer reticulated dome increase with the increase of the weight and the velocity of the impact block, but the change of the velocity of the impact block is more sensitive than the change of weight of the impact block for the effect of the peak of the impact force, and a platform value of the impact force of the single-layer reticulated dome change near a certain value, and the duration time of the impact gradually increase. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of impact on the apex of the single-layer reticulated dome based on numerical analysis. Four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation.


2017 ◽  
Vol 29 (5) ◽  
pp. 703-728 ◽  
Author(s):  
Shuai Li ◽  
Farshad Hedayati Dezfuli ◽  
Jing-quan Wang ◽  
M Shahria Alam

This article investigates the efficiency of a new generation smart isolation system, namely shape memory alloy wire-based lead rubber bearing, for the seismic response control of long-span cable-stayed bridge systems under near-fault ground motions. The constitutive model of shape memory alloy wire-based lead rubber bearings is coded and implemented into OpenSees as a new user element. This user element can accurately predict the re-centering capability and energy dissipation capacity of shape memory alloy wire-based lead rubber bearing under different excitations. The Sutong cable-stayed bridge in China, with a main span of 1088 m, is taken as an example. Results reveal that implementing shape memory alloy wires into lead rubber bearings can effectively increase the self-centering property and, as a result, reduce the residual deformation in shape memory alloy wire-based lead rubber bearings under near-fault ground motions. Shape memory alloy wires lead to an increase in the horizontal stiffness and energy dissipation capacity of shape memory alloy wire-based lead rubber bearings. The deck displacement is restricted effectively, and a superior structural performance is achieved in terms of the deck acceleration. Shape memory alloy wire-based lead rubber bearings can effectively reduce the base shear and base moment of the towers. However, it is observed that an increase in the shape memory alloy wire diameter may have negligible effect on the deck acceleration, tower base shear and moment, and in some cases, on the pier base shear and moment.


2011 ◽  
Vol 368-373 ◽  
pp. 1125-1129
Author(s):  
Chang Jiang Liu ◽  
Jin Long Wang

The finite element model about greenhouse canopy of seismic analysis was setted up, The finite element analysis software ANSYS was used to study structure displacement, stress analysis on greenhouse shed. The results showed that the dangerous part of the canopy were located on upper chord members,lower chord members, web members of the framework and the lower and upper, the inside of both sides of the wall with seismic load.Corresponding to this results ,the main destroied form were the framework damage caused by the bending deformation of upper chord members, lower chord members and the upper web members and the unstability caused by the distortion of both sides of the wall.


2014 ◽  
Vol 893 ◽  
pp. 314-319
Author(s):  
P. Gurusamy ◽  
S. Balasivanandha Prabu ◽  
R. Paskaramoorthy

This paper discusses the influence of die temperature on the solidification behaviour of A356/SiCp composites fabricated by squeeze casting method. Information on the solidification studies of squeeze cast composites is somewhat scarce. Experiments were carried out by varying the die temperatures for cylindrical shaped composite castings K-type thermocouples were interfaced to the die and the temperature-time history was recorded to construct the cooling curves. The cooling curves are also predicted from the finite element analysis (FEA) software ANSYS 13. The experimental and predicted cooling curves are not in good agreement. In addition to, the experimental and theoretical solidification times are studied. It was understood that the increase in the die temperature decreases the cooling rate.


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