scholarly journals Vibration Analysis and Models of Adjacent Structures Controlled by Magnetorheological Dampers

2017 ◽  
Vol 2017 ◽  
pp. 1-21 ◽  
Author(s):  
Michela Basili ◽  
Maurizio De Angelis

This paper deals with the vibration analysis of adjacent structures controlled by a magnetorheological (MR) damper and with the discussion of a numerical procedure for identification and definition of a reliable finite element model. The paper describes an extensive experimental campaign investigating the dynamic response, through shaking table tests, of a tridimensional four-story structure and a two-story structure connected by an MR device. Several base excitations and intensity levels are considered. The structures were tested in nonconnected and connected configuration, with the MR damper operating in passive or semiactive mode. Moreover, the paper illustrates a procedure for the structural identification and the definition of a reliable numerical model valid for adjacent structures connected by MR dampers. The procedure is applied in the original nonconnected configuration, which represents a linear system, and then in the connected configuration, which represents a nonlinear system due to the MR damper. In the end, the updated finite element model is reliable and suitable for all the considered configurations and the mass, damping, and stiffness matrices are derived. The experimental and numerical responses are compared and the results confirm the effectiveness of the identification procedure and the validation of the finite element model.

2003 ◽  
Vol 17 (5) ◽  
pp. 679-690 ◽  
Author(s):  
Dong-Woohn Kim ◽  
Jin Koo Lee ◽  
No-Cheol Park ◽  
Young Pil Park

2012 ◽  
Vol 170-173 ◽  
pp. 3116-3120
Author(s):  
Tao Wang ◽  
Zhong Qiang Fang ◽  
Hao Li

Blasting construction of Houyuntai Mountain tunnels has vibration influence on ground masonry structures. 3-D finite element model is established to analyze this problem which indicates the house’s vibration response velocity induced by blasting loads. According to this analysis, the structure range of removal and strengthening is assured based on the allowable safety standard of 0.02~0.025m/s of blasting vibration. They include that the houses in 20m range of both sides of horizontal tunnel axis should be removed; the security in 20~28m range is not good, as a result the houses should be removed or strengthened; and the security over 28m range is good for houses. Moreover, some factors such as construction quality can influence houses’ anti-vibration safety.


Author(s):  
OMF Morais ◽  
CMA Vasques

The main specification in the verification by testing of space hardware vulnerability to shock excitations is the shock response spectrum. Although it compiles the most relevant information needed to describe the overall shock environment characteristics, shock testing still poses various difficulties and uncertainties concerning the suitability and operation of the shock test system used, and the adequate definition of the underlying test parameters. The approach followed from the interpretation of typical shock testing specifications to the development, validation, and characterization of the developed shock test system, including the definition and design of the relevant parameters influencing the attained shock environment, is described in this paper. The shock testing method here presented consists of a pendular in-plane resonant mono-plate shock test apparatus where the structural response of the ringing plate depends upon well-defined controllable parameters (e.g. impact velocity, striker shape, mass, and contact stiffness), which are parametrically determined to achieve the target shock environment specification. The concept and analytical model of two impacting bodies are used in a preliminary analysis to perform a rigid body motion analysis and contact assessment. A detailed finite element model is developed for the definition of the ringing plate dimensions, analysis of the plate dynamics and virtual shock testing. The assembled experimental apparatus is described and a test campaign is undertaken in order to properly characterize and assess the design and test parameters of the system. The developed shock test apparatus and corresponding finite element model are experimentally verified and validated. As a result of this study, a reliable finite element modeling methodology available for future shock test simulation and prediction of the experimental results was created, being an important tool for the adjustment of the shock test input parameters for future works. The developed shock test system was well characterized and is readily available to be used for shock testing of space equipment with varying specifications.


2021 ◽  
Vol 79 ◽  
pp. 103053
Author(s):  
Eero Avi ◽  
Aleksi Laakso ◽  
Jani Romanoff ◽  
Heikki Remes ◽  
Ingrit Lillemäe-Avi

Sign in / Sign up

Export Citation Format

Share Document