The determination of frequency domain soil parameters of horizontally layered structure by using dipole-dipole array

2019 ◽  
Vol 32 (5) ◽  
pp. e2578
Author(s):  
Zhong-Xin Li ◽  
Shao-Wei Rao
Keyword(s):  
Frequency Domain ◽  
Layered Structure ◽  
Soil Parameters

Error analyses of a Multi-Input-Multi-Output cantilever beam test

2021 ◽  
pp. 107754632110337
Author(s):  
Arup Maji ◽  
Fernando Moreu ◽  
James Woodall ◽  
Maimuna Hossain
Keyword(s):  
Transfer Function ◽  
Frequency Domain ◽  
Cantilever Beam ◽  
Transfer Functions ◽  
Linear Superposition ◽  
Transfer Function Matrix ◽  
Error Analyses ◽  
Pseudo Inverse ◽  
Function Matrix

Multi-Input-Multi-Output vibration testing typically requires the determination of inputs to achieve desired response at multiple locations. First, the responses due to each input are quantified in terms of complex transfer functions in the frequency domain. In this study, two Inputs and five Responses were used leading to a 5 × 2 transfer function matrix. Inputs corresponding to the desired Responses are then computed by inversion of the rectangular matrix using Pseudo-Inverse techniques that involve least-squared solutions. It is important to understand and quantify the various sources of errors in this process toward improved implementation of Multi-Input-Multi-Output testing. In this article, tests on a cantilever beam with two actuators (input controlled smart shakers) were used as Inputs while acceleration Responses were measured at five locations including the two input locations. Variation among tests was quantified including its impact on transfer functions across the relevant frequency domain. Accuracy of linear superposition of the influence of two actuators was quantified to investigate the influence of relative phase information. Finally, the accuracy of the Multi-Input-Multi-Output inversion process was investigated while varying the number of Responses from 2 (square transfer function matrix) to 5 (full-rectangular transfer function matrix). Results were examined in the context of the resonances and anti-resonances of the system as well as the ability of the actuators to provide actuation energy across the domain. Improved understanding of the sources of uncertainty from this study can be used for more complex Multi-Input-Multi-Output experiments.

scholarly journals Parametric Analysis of Rotational Effects in Seismic Design of Tall Structures

2021 ◽  
Vol 11 (2) ◽  
pp. 597
Author(s):  
Milan Sokol ◽  
Rudolf Ároch ◽  
Katarína Lamperová ◽  
Martin Marton ◽  
Justo García-Sanz-Calcedo
Keyword(s):  
Seismic Design ◽  
Parametric Study ◽  
Tall Buildings ◽  
Soil Parameters ◽  
Eurocode 8 ◽  
Tall Structures ◽  
Rotational Components ◽  
Different Types ◽  
Depth Study

This paper uses a parametric study to evaluate the significance of the rotational components of Earth’s motion in a seismic design. The parametric study is based on the procedures included in Eurocode 8, Part 6. Although the answer to the question of when the effects of rotational components are important is quite a complex one and requires a more in-depth study, our aim was to try to assess this question in a relatively quick manner and with acceptable accuracy. The first part of the paper is devoted to derivation of a simple formula that can be used for expressing the importance of rotational components in comparison with the classic seismic design without their usage. The quasi-static analysis, assuming inertial forces, is used. A crucial role plays the shape of the fundamental mode of the vibration. Due to simplicity reasons, well-known expression for estimation of the first eigenmode as an exponential function with different power coefficients that vary for different types of buildings is used. The possibility of changing the soil parameters is subsequently included into the formula for estimation of the fundamental frequency of tall buildings. In the next part, the overall seismic analyses of complex FEM models of 3D buildings and chimneys are performed. The results from those analyses are then compared with those from simplified calculations. The importance of the soil characteristics for determination of whether it is necessary to take into account the rotational effects is further discussed.

Determination of the layered structure of baryta based heritage photographs by infrared ellipsometry

2019 ◽  
Vol 36 ◽  
pp. 174-182
Author(s):  
J.M. Flores-Camacho ◽  
A. Nieto-Villena ◽  
J.R. Martínez ◽  
J.A. de la Cruz-Mendoza ◽  
G. Ortega-Zarzosa ◽  
...  
Keyword(s):  
Layered Structure ◽  
Infrared Ellipsometry

scholarly journals Cs[Tf2N]: a second polymorph with a layered structure

2018 ◽  
Vol 74 (4) ◽  
pp. 551-554
Author(s):  
Jared T. Stritzinger ◽  
Janelle E. Droessler ◽  
Brian L. Scott ◽  
George S. Goff
Keyword(s):  
Ionic Liquid ◽  
Solid State ◽  
Opposite Direction ◽  
Layered Structure ◽  
Layer Structure ◽  
Structural Determination ◽  
Polar Surface ◽  
Trifluoromethyl Groups

The structural determination of the ionic liquid, caesium bis[(trifluoromethyl)sulfonyl]imide or poly[[μ4-bis[(trifluoromethyl)sulfonyl]imido]caesium(I)], Cs[N(SO2CF3)2] or Cs[Tf2N], reveals a second polymorph that also crystallizes in a layer structure possessing monoclinic P21/c symmetry at 120 K instead of C2/c for the known polymorph [Xue et al. (2002). Solid State Sci. 4, 1535–1545]. The caesium ions in the cationic layers are coordinated by the sulfonyl groups of the bistriflimide molecules from anion layers while the trifluoromethyl groups are oriented in the opposite direction, forming a non-polar surface separating the layers. The layer direction is (100).

scholarly journals Determination of Physical and Chemical Soil Parameters on Selenium Adsorption, Desorption by Rice Growing Soil

2014 ◽  
Vol 13 (4-8) ◽  
pp. 147-155
Author(s):  
N. Alifar ◽  
A.R. Zaharah ◽  
C.F. Ishak ◽  
Y. Awang ◽  
B. Khayambash
Keyword(s):  
Soil Parameters ◽  
Chemical Soil ◽  
Adsorption Desorption ◽  
Physical And Chemical
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