Dynamic Response on Earthquake Analysis of Bridge Structure Isolated by Lead-Core Rubber Bearing

2010 ◽  
Vol 163-167 ◽  
pp. 4251-4256
Author(s):  
Hai Xu Yang ◽  
Hai Biao Wang ◽  
Bao Kuan Li ◽  
Jian Gang Yao

The dynamic analysis of earthquake responses of one simple bridge structure supported by hinged and rolled bearing and another simple bridge structure isolated by lead-core rubber bearings was described in elastic-plastic range. The relative displacements and accelerations of the structures were calculated under different amplitude earthquake waves in order to observe the influence of lead-core rubber bearing on earthquake- resistance of bridges. The availability of the analysis model, hysteretic model and relevant parameters adopted as well as the computation program developed are verified. According to the analysis of dynamic response data, the lead-core rubber bearings with proper parameters are used to improve the dynamic performance of the structures, the seismic response of the bridge deck and pier would therefore be greatly reduced, the safety and seismic performance of the structure are globally raised, earthquake- resistance could be increased, and rather good economic benefits have been achieved as well. The analysis can provide accurately the reference basis for construction design.

2012 ◽  
Vol 500 ◽  
pp. 186-191
Author(s):  
Fu Chun Tao ◽  
Guang Chao Chen ◽  
Bin Jiang ◽  
Bo Chen ◽  
Yan Ding

Based on the field research, we found that in the course of high-speed face milling aluminum, Cutters components prone to deformation as the role of load such as Centrifugal force, Cutting force and Preload. The deformation will directly affect the the dynamic performance of the cutter. So its necessary to reveal the dynamic response of the deformation cutter. We base on the Dynamic model and the modal analysis model, Obtained the deformation cutters dynamic simulation which the cutters deformation is come from the ANSYS. At last we got the method of identifying cutters deflection deformation by vibration signal. With the method we can effectively identifying milling distortion In the cutting process.


2013 ◽  
Vol 748 ◽  
pp. 345-349
Author(s):  
Chun Shu Li ◽  
Guang Ming Yuan ◽  
Hao Feng

Rubber bearings are used widely in small and medium-span highway bridge structure. In this paper the transient dynamics of the plate rubber bearing and the pot rubber bearing which are widely used in practical engineering is analyzed. And the fatigue life of bridge bearing is estimated using reliability theory


Author(s):  
Tengjiao Lin ◽  
Daokun Xie ◽  
Ziran Tan ◽  
Bo Liu

The aim of this paper is to investigate the influence of structure parameters on the vibration characteristics and improve the dynamic performance of marine gearbox. A finite element model was established to solve the dynamic response by using modal superposition method. Based on the theory of multi-objective optimization design, the structure sensitivity analysis model of marine gearbox was established, which takes the structure parameters of the housing as design variables. The modal and response sensitivity was obtained by using the optimal gradient method. According to the results of sensitivity analysis, a modal and response optimization model of marine gearbox was established. The objective was to avoid natural frequencies from the excitation frequencies and minimize the root mean square of vibration acceleration of the evaluating points on the surface of housing. Then the modal optimization and response optimization of gearbox were carried out by using zero-order and first-order optimization method. The results indicate that the dynamic optimization of the gearbox can be achieved. After optimization, the amplitude of vibration acceleration of the evaluating points on the housing surface has been reduced and the resonance of marine gearbox can be avoided.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Adarsh Anand ◽  
Subhrata Das ◽  
Mohini Agarwal ◽  
Shinji Inoue

PurposeIn the current market scenario, software upgrades and updates have proved to be very handy in improving the reliability of the software in its operational phase. Software upgrades help in reinventing working software through major changes, like functionality addition, feature enhancement, structural changes, etc. In software updates, minor changes are undertaken which help in improving software performance by fixing bugs and security issues in the current version of the software. Through the current proposal, the authors wish to highlight the economic benefits of the combined use of upgrade and update service. A cost analysis model has been proposed for the same.Design/methodology/approachThe article discusses a cost analysis model highlighting the distinction between launch time and time to end the testing process. The number of bugs which have to be catered in each release has been determined which also consists of the count of latent bugs of previous version. Convolution theory has been utilized to incorporate the joint role of tester and user in bug detection into the model. The cost incurred in debugging process was determined. An optimization model was designed which considers the reliability and budget constraints while minimizing the total debugging cost. This optimization was used to determine the release time and testing stop time.FindingsThe proposal is backed by real-life software bug dataset consisting of four releases. The model was able to successfully determine the ideal software release time and the testing stop time. An increased profit is generated by releasing the software earlier and continues testing long after its release.Originality/valueThe work contributes positively to the field by providing an effective optimization model, which was able to determine the economic benefit of the combined use of upgrade and update service. The model can be used by management to determine their timelines and cost that will be incurred depending on their product and available resources.


Author(s):  
Jahangir Rastegar ◽  
Dake Feng

In general, mechanical systems with closed-loop mechanisms can achieve significantly higher operating speeds as compared to open-loop mechanisms such as robots performing identical tasks. In this brief paper, the reason for the superior dynamic performance of closed-loop mechanisms as compared to open-loop mechanisms performing identical tasks is shown to be the inherent dynamic response limitations of the actuation devices in open-loop dynamic systems. Several examples are provided.


Author(s):  
Masahiko Mori ◽  
Zachary I. Piner ◽  
Ke Ding ◽  
Adam Hansel

This paper presents the virtual machine tool environment Mori Seiki established for the evaluation of static, dynamic, and thermal performance of Mori Seiki machine tools. In this system environment, machining accuracy and quality are the main focus for each individual analysis discipline. The structural analysis uses the Finite Element Method (FEM) to monitor and optimize the static rigidity of the machine tool. Correlation between physical experiments and digital simulation is conducted to validate and optimize the static simulation accuracy. To accurately evaluate and effectively optimize dynamic performance of the machine tool in the virtual environment, the critical modal parameters such as damping and stiffness are calibrated based on experimental procedures which results in precise setup of the frequency response models. Computational Fluid Dynamic (CFD) analysis model is built in the environment so that the thermal perspective of the machine tool is evaluated and thermal deformation is monitored. This paper demonstrates compatibility of the digital simulation with physical experiments and success in integrating theoretical simulation processes with practical Mori Seiki machine tool development.


2021 ◽  
Vol 9 (1) ◽  
pp. 96-103
Author(s):  
Ruba Asim Hamza ◽  
Amged Osman Abdelatif

Sudan is one of the developing countries that suffers from a lack of electricity, where the national electrification rate is estimated at 38.5%. In order to solve this problem, it is possible to use renewable energy sources such as wind energy. Beside many aspects to be considered at the design of wind turbine foundations, more attention should be given to the geotechnical part. There are many types of foundations for wind turbines. The foundation must satisfy two design criteria: 1) It should be safe against bearing failure in soils under design loads and settlements during the life of the structure must not cause structural damage; 2) In addition to static loads, wind turbine foundations loads are extremely eccentrically and the loading is usually highly dynamic. Therefore, the selection of foundation type should consider these two criteria taking into account the nature and magnitude of these loads. This paper presents a review of different types of wind turbine foundations of focusing on on-shore wind turbine foundation types and the dynamic response of wind turbine. The paper also demonstrate experimentally the dynamic response of the wind turbines using wind tunnel facility test on a scaled model.  


2004 ◽  
Vol 04 (03) ◽  
pp. 379-402 ◽  
Author(s):  
N. LAKSHMANAN ◽  
K. MUTHUMANI ◽  
N. GOPALAKRISHNAN ◽  
K. SATHISH KUMAR

Framed type foundation structures supporting turbo-generator machinery in a power plant have stringent vibration limits to ensure proper functioning of turbine generators without any breakdown. Current dynamic analysis methodology for such dynamically sensitive structures involves modal synthesis considering a single value of operating speed for the machinery and a uniform dynamic modulus for the frame material, which cannot be realized in site conditions. Such variations in the dynamic modulus across the whole structure and running speed of the machinery during normal operation have a profound impact on its dynamic performance which may result in alarmingly increasing amplitudes leading to subsequent breakdown of the machinery. A new methodology is outlined that combines the effects of the two variations by way of considering an enhanced range of speeds on either side of the operating speed for the modal synthesis process. This study shows the effects of variations in the dynamic modulus and operating speed on the peak dynamic response of a typical framed turbo-generator foundation structure. The modal synthesis process adopted in the study includes the significant modes in the sub-resonant range and a band of modes around the operating speed to obtain the peak response of the framed structure.


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