Stochastic response control of particle dampers under random seismic excitation

2020 ◽  
Vol 481 ◽  
pp. 115439
Author(s):  
Zheng Lu ◽  
Yuan Liao ◽  
Zhikuang Huang
Keyword(s):  
Seismic Excitation ◽  
Stochastic Response ◽  
Response Control ◽  
Particle Dampers

Dynamic Stability and Failure Probability Analysis of Dome Structures Under Stochastic Seismic Excitation

2014 ◽  
Vol 14 (05) ◽  
pp. 1440001 ◽  
Author(s):  
Jie Li ◽  
Jun Xu
Keyword(s):  
Dynamic Stability ◽  
Failure Probability ◽  
Stochastic System ◽  
Dynamic Instability ◽  
Seismic Excitation ◽  
Stochastic Dynamic ◽  
Deterministic System ◽  
Density Evolution ◽  
Stochastic Response ◽  
Strength Failure

The intrinsic relationship between deterministic system and stochastic system is profoundly revealed by the probability density evolution method (PDEM) with introduction of physical law into the stochastic system. On this basis, stochastic dynamic stability analysis of single-layer dome structures under stochastic seismic excitation is firstly studied via incorporating an energetic physical criterion for identification of dynamic instability of dome structures into PDEM, which yields to sample stability (stable reliability). However, dynamic instability is not identical to structural failure definitely, where strength failure can be experienced not only in the stable structure but also when the structure is out of dynamic stability. It is practically feasible to decouple the stochastic dynamic response of dome structures to be a stable one and an unstable one according to the generalized density evolution equation (GDEE). Consequently, the global failure probability can be investigated separately based on the corresponding independent stochastic response. For unstable failure probability assessment, the failure probability is the unstable probability if the dome's failure is attributed to instability, whereas inverse absorbing is firstly implemented to get rid of the stochastic response before instability and a complementary process is filled in the safe domain immediately to finally assess the probability of strength failure after dynamic instability.

Protection of Seismic Structures Using Passive and Semi-Active Friction Typed Multiple Tuned Mass Dampers

2009 ◽  
Author(s):  
Ging-Long Lin ◽  
Chi-Chang Lin ◽  
Jer-Fu Wang
Keyword(s):  
Primary Structure ◽  
Tuned Mass Damper ◽  
Seismic Excitation ◽  
Tuned Mass Dampers ◽  
Response Control ◽  
Friction Forces ◽  
Numerical Result ◽  
Mass Damper ◽  
Active Friction ◽  
Arbitrary Intensity

Although the design and applications of linear tuned mass damper (TMD) systems are well developed, nonlinear TMD systems are still developing. In this paper, the application of multiple semi-active friction tuned mass dampers (SAF-MTMD) for response control of a multistory structure under seismic excitation is investigated. The friction forces of the SAF-MTMD are controllable. A non-sticking friction (NSF) controller, which is able to keep each of the TMD activated and in its slip state throughout an earthquake with arbitrary intensity, was conducted. A parametric study is performed to investigate the effectiveness of SAF-MTMD. The seismic performance of the SAF-MTMD is also compared with the single and multiple passive friction tuned mass dampers (PF-TMD/PF-MTMD). The numerical result shows that the SAF-MTMD is superior to PF-MTMD in reducing the response of the primary structure under the seismic excitation.

Systematization of Shock Response Control Based on Momentum Exchange and Energy Exchange and Its Application to Lunar/Planetary Spacecraft

Impact ◽  
2019 ◽  
Vol 2019 (10) ◽  
pp. 73-75
Author(s):  
Susumu Hara
Keyword(s):  
Energy Exchange ◽  
Control Mechanism ◽  
Cost Effective ◽  
Aerospace Engineering ◽  
Single Test ◽  
Momentum Exchange ◽  
Mars Rover ◽  
Response Control ◽  
Shock Control ◽  
Shock Response

Professor Susumu Hara is based at the Department of Aerospace Engineering, Nagoya University in Japan explains that when the Mars rover Opportunity was set to land on that planet in the first weeks of 2004, onlookers held their breath as it dropped from orbit and hurtled toward the red surface. 'Any failure in the calculations or landing systems would mean a harder than expected impact,' he highlights. 'The impacts sustained by a rover such as Opportunity can derail a mission before it even starts, damaging cargo or vital systems required to complete the mission.' Impacts occur during landing but also as the craft enters the atmosphere, when it makes sudden moves, while it is on surface or when debris strikes it. 'Therefore, a system and materials to protect a craft are vital,' outlines Hara. 'Surprisingly, the solutions to this problem are not sophisticated. In fact, most craft still employ devices resembling automobile bumpers, which absorb the energy from an impact by crumpling under the force of said impact.' Unfortunately, these cannot be reused, even during testing phases a new prototype is required after every single test run. Recent missions also employed techniques like airbags or sky cranes. While successful they too have drawbacks. 'Airbags create huge rebounds which can jostle the craft and the contents inside while sky cranes are extremely costly to develop,' Hara says. For this reason, he is dedicated to designing a new highly reliable and cost-effective shock control mechanism.

Dynamics Response Control of a Mindlin-Type Beam

2017 ◽  
Vol 17 (03) ◽  
pp. 1750039 ◽  
Author(s):  
Kenan Yildirim ◽  
Seda G. Korpeoglu ◽  
Ismail Kucuk
Keyword(s):  
Optimal Control ◽  
Partial Differential Equations ◽  
Maximum Principle ◽  
Control Problem ◽  
Control Function ◽  
Initial Boundary ◽  
Response Control ◽  
Adjoint Variables ◽  
Dynamics Response ◽  
Optimal Control Function

Optimal boundary control for damping the vibrations in a Mindlin-type beam is considered. Wellposedness and controllability of the system are investigated. A maximum principle is introduced and optimal control function is obtained by means of maximum principle. Also, by using maximum principle, control problem is reduced to solving a system of partial differential equations including state, adjoint variables, which are subject to initial, boundary and terminal conditions. The solution of the system is obtained by using MATLAB. Numerical results are presented in table and graphical forms.

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