Reliability-Based Design of Tuned Mass Damper Using Monte Carlo Simulation Under Artificial Earthquake Records

2017 ◽  
Vol 17 (10) ◽  
pp. 1750121 ◽  
Author(s):  
Amin Gholizad ◽  
Seyyed Davood Ojaghzadeh Mohammadi
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Lateral Displacement ◽  
Structural Parameters ◽  
Wavelet Packet ◽  
Tuned Mass Damper ◽  
Cross Sectional ◽  
Earthquake Records ◽  
Mass Damper ◽  
Ground Motion Records

Displacement- and reliability-based designs of tuned mass damper (TMD) for a shear building are studied herein. Different sources of uncertainties such as earthquake records and their peak ground accelerations (PGA), masses of floors, cross-sectional dimensions of structural members, damping of the structure and modulus of elasticity are considered. Monte Carlo simulation (MCS) is used for evaluating the performance of the designed TMD. A method for generating artificial earthquake record by using wavelet packet transform (WPT) and particle swarm optimization (PSO) is proposed to generate artificial records for areas without sufficient strong ground motion records. An illustrative example is used to study the displacement- and reliability-based designs of TMD, which are related to minimizing the structural displacement and maximizing the performance of TMD, respectively. In addition, the performance of TMD on mitigating the response of structure and its reliability under uncertain parameters of loading and structural properties are investigated. The results show that a displacement-based designed TMD could reduce the lateral displacement of a structure. Furthermore, it illustrates that the reliability-based designed TMD has a better performance in real condition of loading and structural parameters.

scholarly journals Evaluation of scatter suppression algorithm for X-ray exposure of soft tissue equivalent phantoms over nominal energy range using FLUKA code

2021 ◽  
Vol 47 (2) ◽  
pp. 779-789
Author(s):  
Samson O Omondi ◽  
Innocent J Lugendo ◽  
Ramadhan R Kazema ◽  
Robert Kinyua
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Soft Tissue ◽  
Energy Range ◽  
Scatter Correction ◽  
Tissue Imaging ◽  
Diagnostic Image Quality ◽  
Cross Sectional ◽  
X Ray ◽  
Tissue Equivalent

Soft tissue imaging is heavily impaired by streaks and cupping effects associated with X-ray scatter. Quality of images from projection imaging may be improved by the use of enhanced anti-scatter grids’ designs with potency to reject significant scatter. However, optimization of grid characteristics requires investigation to improve diagnostic image quality. Transmitted scatter spatially distributed degrades images engendering need for effective scatter correction protocols. This study investigated the pre-scan scatter suppression algorithm for X-ray exposure of soft tissue equivalent phantoms over nominal energy range. Adipose tissue and polymethyl methacrylate phantoms of cross-sectional area (30 x 30) cm2 and of varying thickness from 2 to 8 cm in 1 cm increments were successively exposed using energy ranging between 20–50 kVp. Monte Carlo simulation based on FLUKA code and flair interface was used to generate an input file for execution. The source simulated five cycles of ten million photons each of annular X-ray photon beam of radius, r = 0.5 cm at fixed field of view (FOV) through anti-scatter grid on to gadolinium oxysulfide detector. The transmitted total, scatter and primary estimates were evaluated with and without grids over varying phantom thicknesses, energy and grid design features. The simulated and experimental results obtained were comparable and in agreement with previous literature. Pearson’s correlation coefficients for scatter fraction and scatter to primary ratio were 0.983 and 0.981, respectively. The strong correlation between simulation and experiment results indicated correctness in methodology and protocol. The algorithms and protocols in the simulation would be appropriate for designing grids with enhanced scatter rejection capabilities. Keywords: FLUKA code, Monte Carlo simulation, Scatter suppression algorithm, Scatter correction, X-ray imaging systems.  

scholarly journals Investigation responses of the diagrid structural system of high-rise buildings equipped with Tuned mass damper using new dynamic method

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Arash Karimipour ◽  
Mansour Ghalehnovi ◽  
Mahmoud Edalati ◽  
Mehdi Barani
Keyword(s):  
Dynamic Method ◽  
Lateral Displacement ◽  
Tall Buildings ◽  
Tuned Mass Damper ◽  
Structural System ◽  
Base Shear ◽  
Structural Behaviour ◽  
High Rise ◽  
Mass Damper ◽  
Story Drift

Due to the shortage of land in cities and population growth, the significance of high rise buildings has risen. Controlling lateral displacement of structures under different loading such as an earthquake is an important issue for designers. One of the best systems is the diagrid method which is built with diagonal elements with no columns for manufacturing tall buildings. In this study, the effect of the distribution of the tuned mass damper (TMD) on the structural responses of diagrid tall buildings was investigated using a new dynamic method. So, a diagrid structural systems with variable height with TMDs was solved as an example of structure. The reason for the selection of the diagrid system was the formation of a stiffness matrix for the diagonal and angular elements. Therefore, the effect of TMDs distribution on the story drift, base shear and structural behaviour were studied. The obtained outcomes showed that the TMDs distribution does not significantly affect on improving the behaviour of the diagrid structural system during an earthquake. Furthermore, the new dynamic scheme represented in this study has good performance for analyzing different systems. 

scholarly journals Risk Assessment of Addiction and Tobacco Misuse in Community of the Rural Older Adult, Using Monte Carlo Simulation Sampling

2020 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Elham Rezaian ◽  
Masoud Karimi ◽  
Ebrahim Nazari Far ◽  
Mahsa Yarelahi ◽  
Abdolrahim Asadollahi ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Marital Status ◽  
Sample Size ◽  
Rural Areas ◽  
Risky Behaviors ◽  
Cross Sectional Study ◽  
Snowball Sampling ◽  
Cross Sectional ◽  
Significant Difference

Background: Illegal drug abuse is an important challenge that is not adequately addressed with respect to gerontology in rural areas. Patients and Methods: In this cross-sectional study 641 people aged 60 years or older supported by rural health centers in Southern Iran were investigated (310 and 331 men and women, respectively). To take a sample size of 326, snowball sampling was used. Then, the sample size was developed and simulated to 1.65 million rural elderly using the Monte Carlo simulation and bootstrapping technique (upon the 2016 national census), calculated in SPSS V.25. The ASSIST-WHO, 2017 instrument was used to collect the data. Results: A significant difference was found between the mean sub-variables of marital status using the MANOVA. Widowhood and divorce had more impact on the tendency to addiction compared to the other factors on marital status. Nomads and farmers were more vulnerable to be addicted than those occupied in the public sector. It was also confirmed by the Eta2 coefficient that older men feeling loneliness have a higher tendency to commit risky behaviors. Conclusions: Being a nomad or framer and widowhood and divorce increased the tendency of male elderly towards illegal drugs. Further studies are required to develop guidelines for policy-makers concerning the rural aging community.

Effect of Random Material Parameter in the Shell Structures

2013 ◽  
Vol 275-277 ◽  
pp. 1302-1305
Author(s):  
Hyuk Chun Noh
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Elastic Modulus ◽  
Isotropic Material ◽  
Material Parameter ◽  
Structural Parameters ◽  
Shell Structures ◽  
Random Nature ◽  
Good Agreement

The random nature of structural parameters is to affect the behavior of the structure which cannot be detected in the context of deterministic analyses. Taking into account the randomness in the material parameter, we evaluate probabilistic behavior of the shell structures made of isotropic material. Specifically, the elastic modulus is taken to be random since the parameter plays an utmost important role in the behavior of structures. The results of the proposed scheme are compared with those based on Monte Carlo simulation. It is observed that the proposed scheme is in good agreement with the MCS, which shows the adequacy of the proposed scheme.

Combining Separable Monte Carlo With Importance Sampling for Improved Accuracy

2011 ◽  
Author(s):  
Anirban Chaudhuri ◽  
Raphael T. Haftka
Keyword(s):  
Monte Carlo ◽  
Importance Sampling ◽  
Tuned Mass Damper ◽  
Reliability Based Design ◽  
Reliability Method ◽  
Mass Damper ◽  
Mc Simulation ◽  
Separable Monte Carlo ◽  
Improving Accuracy ◽  
Improved Accuracy

Monte-Carlo (MC) methods are often used to carry out reliability based design of structures. Methods that improve the accuracy of MC simulation include Separable Monte Carlo (SMC), Markov Chain Monte-Carlo, and importance sampling. We explore the utility of combining SMC and importance sampling for improving accuracy. The accuracy of the estimates is compared for crude MC, SMC, importance sampling and combined method for a composite plate example and a tuned mass damper example. For these examples SMC and importance sampling reduced the error individually by factors of 2 to 5, and the combination reduced it further by about a factor of 2. The results were also compared with the first order reliability method (FORM). FORM was grossly inaccurate for the tuned mass-damper example which has a failure region bounded by safe regions on either side.

Electron Scattering in Solids

1990 ◽  
Vol 48 (2) ◽  
pp. 4-5
Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Angular Distribution ◽  
Elastic Scattering ◽  
Electron Scattering ◽  
Cross Sections ◽  
Expansion Method ◽  
Electron Excitation ◽  
Partial Wave Expansion ◽  
Backscattered Electrons

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

Sign in / Sign up

Export Citation Format

Share Document