scholarly journals Identification of Natural Frequency of Low Rise Building on Soft Ground Profile using Ambient Vibration Method

2018 ◽  
Vol 995 ◽  
pp. 012100
Author(s):  
A F Kamarudin ◽  
M H Zainal Abidin ◽  
S N Mokhatar ◽  
M E Daud ◽  
A Ibrahim ◽  
...  
Keyword(s):  
Natural Frequency ◽  
Ambient Vibration ◽  
Soft Ground ◽  
Vibration Method ◽  
Ground Profile

scholarly journals Effects of Precast Cladding Systems on Dynamic Characteristics of Steel Frame Buildings by Ambient and Free Vibration Tests

2017 ◽  
Vol 2017 ◽  
pp. 1-20 ◽  
Author(s):  
Jun Ma ◽  
Shinji Nakata ◽  
Akihito Yoshida ◽  
Yukio Tamura
Keyword(s):  
Free Vibration ◽  
Dynamic Characteristics ◽  
Steel Frame ◽  
Ambient Vibration ◽  
Test Cases ◽  
Vibration Method ◽  
External Wall ◽  
Wide Range ◽  
Cladding Panels ◽  
Vibration Tests

Full-scale tests on a one-story steel frame structure with a typical precast cladding system using ambient and free vibration methods are described in detail. The cladding system is primarily composed of ALC (Autoclaved Lightweight Concrete) external wall cladding panels, gypsum plasterboard interior linings, and window glazing systems. Ten test cases including the bare steel frame and the steel frame with addition of different parts of the precast cladding system are prepared for detailed investigations. The amplitude-dependent dynamic characteristics of the test cases including natural frequencies and damping ratios determined from the tests are presented. The effects of the ALC external wall cladding panels, the gypsum plasterboard interior linings, and the window glazing systems on the stiffness and structural damping of the steel frame are discussed in detail. The effect of the precast cladding systems on the amplitude dependency of the dynamic characteristics and the tendencies of the dynamic parameters with respect to the structural response amplitude are investigated over a wide range. Furthermore, results estimated from the ambient vibration method are compared with those from the free vibration tests to evaluate the feasibility of the ambient vibration method.

scholarly journals Evaluation of Steel Stairwell Dynamic Characteristics, Under Few Mass Configurations Using Ambient Vibration Method

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Ahmad Fahmy Kamarudin ◽  
◽  
Shahrul Niza Mokhatar ◽  
Mohammad Soffi Md Noh ◽  
Mohammad Azim Mohd Sulaiman ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Ambient Vibration ◽  
Vibration Method

The El Achour (Algiers, Algeria) landslide delimitation using the H/V ambient vibration method

2017 ◽  
Vol 10 (18) ◽  
Author(s):  
Ghani Cheikh Lounis ◽  
Omar Mimouni ◽  
Djamel Machane ◽  
Amina Bacha
Keyword(s):  
Ambient Vibration ◽  
Vibration Method

Analysis of Seismic Resistance Capability of Masonry Structure

2011 ◽  
Vol 255-260 ◽  
pp. 2380-2387
Author(s):  
Hong Biao Liu ◽  
Xun Guo ◽  
Yuan Yuan Yu
Keyword(s):  
Numerical Simulation ◽  
Wenchuan Earthquake ◽  
Natural Frequency ◽  
Masonry Structure ◽  
Ambient Vibration ◽  
Seismic Resistance ◽  
Earthquake Response ◽  
Masonry Building ◽  
Maximum Acceleration ◽  
Story Drift

In order to analysis the seismic resistance mechanism of Staff apartment block of Beichuan telecommunication bureau (a six-storey-high masonry building in Beichuan County, meizoseismal area of Wenchuan earthquake), which just suffered from a moderate damage in the earthquake, ambient vibration survey and numerical simulation of structural earthquake response are carried out. Based on the ambient vibration survey, the natural frequencies of the building are acquired after Wenchuan earthquake. The first natural frequency in transverse and longitudinal is 3.45Hz and 3.65Hz, respectively, and the torsion frequency is 4.05Hz. The second natural frequency of the building in transverse is 7.55Hz, and that in longitudinal is not tested out. With Abaqus software, the earthquake response is computed out by inputting Wolong earthquake wave recorded in Wenchuan earthquake. The results of numerical simulation illustrate that the maximum acceleration amplification factor of the top floor in transverse and longitudinal is 5.28 and 6.68 severally. The maximum inter-story drift in transverse and longitudinal is 1/359 and 1/274 respectively, which are all exceed the limit of inter-story drift of masonry structure.

Vibration method for grading of large cross-section coniferous timber species

Holzforschung ◽  
2012 ◽  
Vol 66 (3) ◽  
Author(s):  
Francisco Arriaga ◽  
Guillermo Íñiguez-González ◽  
Miguel Esteban ◽  
Ferenc Divos
Keyword(s):  
Natural Frequency ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Longitudinal Vibration ◽  
Strong Relationship ◽  
Modulus Of Rupture ◽  
Bending Test ◽  
Timber Species ◽  
Vibration Method ◽  
Dynamic Modulus Of Elasticity

Abstract The non-destructive testing (NDT) of timber using the longitudinal vibration method is based on the natural frequency of wood which is in relation to its quality. In the present paper, the suitability of this tool is investigated and the results of grading 395 pieces are presented. Structural timber of Radiata pine (Pinus radiata D. Don.), Scots pine (Pinus sylvestris L.), and Laricio pine [Pinus nigra ssp. salzmannii (Dunal) Franco] from Spanish sources were investigated. The specimens were tested for bending according to the European standard EN 408 (2003) and the values of strength and stiffness were compared with the results estimated by means of NDT. The vibration equipment applied permits the measurement of the longitudinal natural frequency and mass of the specimen, and then the density and the dynamic modulus of elasticity can be calculated. There is a strong relationship between the static modulus of elasticity obtained from the bending test and the dynamic modulus of elasticity obtained by the NDT technique. There is an acceptable relationship between modulus of rupture and dynamic modulus of elasticity if the visual defects (knot sizes) are taken into account. Acoustic measurements have become widely acceptable, and they have great potential for stress grading of coniferous timber.

Vibration Monitoring of Two Long-Span Floors Equipped with Tuned Mass Dampers

2019 ◽  
Vol 19 (09) ◽  
pp. 1950101 ◽  
Author(s):  
Pei Liu ◽  
Hai-Xin Zhu ◽  
Babak Moaveni ◽  
Wei-Guo Yang ◽  
Shu-Qiang Huang
Keyword(s):  
Natural Frequency ◽  
Dynamic Properties ◽  
Concrete Slab ◽  
Vibration Monitoring ◽  
Ambient Vibration ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Tuned Mass Dampers ◽  
Long Span ◽  
Wood Flooring

This paper presents the field tests and vibration performance assessment of two long-span floors with tuned mass dampers (TMDs). The floors considered are made of steel beams and concrete slabs, as part of a gymnasium with composite floors spanning 36 m in each direction and equipped with 30 TMDs. Operational modal analysis based on ambient acceleration measurements is performed to extract the modal parameters of the floors. Ambient vibration tests were conducted at three stages of construction for each floor, namely (i) after the concrete slab was completed, (ii) after one layer over the concrete slab was added, and (iii) after the flooring (surfacing) was fully finished. The effects of the layers making up the flooring system and of the TMDs on the dynamic properties of the floors are studied. The finite element models of the floors are validated using the identified modal parameters. The effects of natural frequency of TMDs on the dynamic properties of the floors are investigated using the validated model. Finally, the effects of flooring on the vibration serviceability of the two floors are studied with TMDs in operation, when the floors were subjected to crowd-induced rhythmic loading, from which the efficiency of TMDs is assessed numerically. The results show that the coupled vibrations of the two floors with TMDs turned off occur in the first two modes, while the natural frequencies of the floors decrease with the addition of layers. The TMDs in operation break the first mode of the floor into two modes with similar mode shapes, resulting in smaller vibration response and larger damping ratios, which vary with the natural frequency of TMDs. Also, the wood flooring significantly increases the human-induced vibration of the floor, while the plastic flooring shows basically no effect.

Consideration of Factors Towards Lowering the Natural Frequency of MEMS Based Cantilever Structure: Top Mass versus Back Etch Design

2015 ◽  
Vol 780 ◽  
pp. 39-44
Author(s):  
A.W. Khairul Adly ◽  
Y. Wahab ◽  
A.Y.M. Shakaff ◽  
Mazlee Mazalan
Keyword(s):  
Energy Harvesting ◽  
Natural Frequency ◽  
Sensor Node ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Wireless Sensor ◽  
Wireless Sensor Node ◽  
Harvesting Technique ◽  
Cantilever Structure

The ability to self-energize wireless sensor node promote the popularity of energy harvesting technique especially by using ambient vibration as the source of energy. In addition, the successful integration of the energy harvesting element on the same wafer as a wireless sensor node will promote the production in the MEMS scale and will reduce the overall cost of production. The usage of the cantilever structure as the transducer for converting mechanical energy (vibration) due to deflection of cantilever into the electrical energy is possible by depositing piezoelectric material on the cantilever. The usage of cantilever provide the simplest way for fabrication in the MEMS scale and also provide the ability to achieve low natural frequency. This paper present the work done on the simulation of the cantilever structure with the top end and back etch proof mass towards achieving low natural frequency in the MEMS scale by using IntelliSuite software.

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