Random Vibration
Mostrando 1-12 de 15 artigos, teses e dissertações.
-
1. An Enhanced Random Vibration and Fatigue Model for Printed Circuit Boards
Abstract Aerospace vehicles are mostly exposed to random vibration loads during its operational lifetime. These harsh conditions excites vibration responses in the vehicles printed circuit boards, what can cause failure on mission functionality due to fatigue damage of electronic components. A novel analytical model to evaluate the useful life of embedded el
Lat. Am. j. solids struct.. Publicado em: 2017
-
2. Design Optimization of a Random Suspension Device Considering a Reliability Constraint on the Frequency Response Function
Abstract This work deals with the design of a suspension device, idealized as a spring-mass-damper system. The amplitude of a nominal system is constrained to satisfy certain limitations in a given frequency band and the design is to be done as a reliability-based optimization. This constitutes a major difficulty since the constraint becomes a random process
Lat. Am. j. solids struct.. Publicado em: 2016-06
-
3. Influence of slab length on dynamic characteristics of subway train-steel spring floating slab track-tunnel coupled system
A subway train-steel spring floating slab track-tunnel coupling dynamic model, considering short and middle-long wavelength random track irregularities, and longitudinal connection between adjacent slabs of steel spring floating slab track, was developed. And the influence of slab length on dynamic characteristics of the system under different track conditio
Lat. Am. j. solids struct.. Publicado em: 2015-08
-
4. System identification and active vibration control of a flexible structure
The aim of this paper is to illustrate the active control of vibration of a flexible structure using a model-based digital controller. The state-space model of the system is derived using a system identification technique known as the Observer/Kalman Filter Identification (OKID) method together with Eigensystem Realization Algorithm (ERA). Based on the measu
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012
-
5. Controle de vibrações em edifícios submetidos à ação de cargas dinâmicas utilizando amortecedor de massa sintonizando na forma de pêndulo / Vibration control of structures subjected to dynamic loads using tuned pendulum-shaped mass dampers
The ongoing progress of structural analyses and dimensioning, in addition to the continuous advancements in building techniques and material, has made it possible to build taller and more slender structures every day. These structures are also more vulnerable to excessive vibrations caused by dynamic loads like earthquakes, winds, waves, intense traffic, and
Publicado em: 2007
-
6. Mixed H2 / H Infinity control through linear inequalities for flexible structures vibration reduction / Controle H2 / H Infinito via desigualdades matriciais lineares para atenuação de vibrações em estruturas flexiveis
This work has the goal to verify the action of a mixed H2/ Hoo control formulation through output feedback for a structure modelIed in finite elements. Therefore, the pure H2 and Hoo control formulations through output feedback are also verified to validate the described equations in this work for the mixed control and show a reference to their expected resu
Publicado em: 2005
-
7. Sensitivity analysis and optimization of structures under random vibration / Análise de sensibiblidade e otimização de estruturas submetidas a vibrações aleatórias
Problemas de vibração aleatória são problemas em que não se consegue prever o efeito da excitação na estrutura e conseqüentemente não se consegue prever a resposta da estrutura à excitação em um determinado instante de tempo. Essa resposta fica caracterizada por grandezas estatísticas, como a média da resposta do sistema e o desvio padrão, os
Publicado em: 2002
-
8. Análise de sensibiblidade e otimização de estruturas submetidas a vibrações aleatórias / Sensitivity analysis and optimization of structures under random vibration
Problemas de vibração aleatória são problemas em que não se consegue prever o efeito da excitação na estrutura e conseqüentemente não se consegue prever a resposta da estrutura à excitação em um determinado instante de tempo. Essa resposta fica caracterizada por grandezas estatísticas, como a média da resposta do sistema e o desvio padrão, os
Publicado em: 2002
-
9. Determinação experimental de fluxo de potencia em vigas
The objective of this work is to review the mathematical equations involved in the methods of calculation of power flow in beams under bending vibration. Several methods are presented and compared. Some of these methods are traditionally employed and use approximation through finite differences in order to ca1culate power flow. Other methods use parametric m
Publicado em: 2000
-
10. Experimental and numerical analysis of the dynamic wind effect on freestanding latticed telecommunication tower. / Análise numérica e experimental do efeito dinâmico do vento em torres metálicas treliçadas para telecomunicações.
Torres metálicas treliçadas tem sido largamente utilizadas como suporte de antenas de microondas. Devido ao baixo peso e a inexistência de terremotos significativos no Brasil, a força de vento é o fator determinante do projeto destas estruturas. Com o objetivo de determinar estas forças e seus efeitos em torres treliçadas foram realizadas investigaç�
Publicado em: 2000
-
11. A cross sectional epidemiological survey of shipyard workers exposed to hand-arm vibration.
The hand-arm vibration syndrome, widely known as vibration white finger, is a disorder of nerves and blood vessels that occurs in workers exposed to segmental vibration. A cross sectional symptom survey was performed on a sample of workers employed by a large shipyard in the north eastern United States. Random samples were drawn from departments composed of
-
12. Vibration syndrome in Forestry Commission chain saw operators
Taylor, W., Pearson, J., Kell, R. L., and Keighley, G. D. (1971). Brit. J. industr. Med., 28, 83-89. Vibration syndrome in Forestry Commission chain saw operators. A preliminary investigation has been made into the prevalence of the vibration syndrome in the employees of the Forestry Commission (Britain). A questionnaire covered 20 randomly selected employee