Said Elias

Said Elias
University of Twente | UT · Program of Civil Engineering and Management (CEM)

BSc in Civil Engineering, M.Tech in Structural Engineering, PhD in Civil Engineering

About

86
Publications
42,214
Reads
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1,193
Citations
Introduction
I am currently working at CEM group of UT for the project of vision-based SHM of structures. I am editor in Practice Periodical on Structural Design and Construction of ASCE. Also, I am associate editor of several journals such as Shock and Vibration, Journal of Low Frequency Noise, Vibration and Active Control. I have published more than 28 conference papers and more than 35 journal papers so far in the area of my research interest.
Additional affiliations
July 2021 - present
University of Twente
Position
  • Researcher
September 2018 - May 2021
University of Iceland
Position
  • PostDoc Position
May 2012 - February 2016
Herat University
Position
  • Lecturer
Education
July 2011 - October 2017
Indian Institute of Technology Delhi
Field of study
  • Effective Placement and Tuning of Multiple Tuned Mass Damper for Mitigation of Building Vibrations

Publications

Publications (86)
Article
The effectiveness of the multi-mode control of seismically excited building installed with distributed multiple tuned mass dampers (d-MTMDs) is investigated by comparing dynamic response with the other controllers, such as passive friction dampers, semi-active dampers, single tuned mass damper (STMD), and multiple tuned mass dampers (MTMDs-all.top)...
Article
Full-text available
Seismic analysis and energy assessment of building installed with distributed tuned vibration absorbers (d-TVAs) are presented. The performance of d-TVAs is compared with single tuned vibration absorber (STVA) installed at the top of the building. The placements of the d-TVAs are based on the modal properties of the uncontrolled and controlled buil...
Article
The effectiveness of distributed multiple tuned mass dampers (d‐MTMDs) for multimode control of chimney for along‐wind response is presented. A concrete chimney considered herein is an assemblage of two‐dimensional (2D) beam elements, each assumed to have constant diameter over the element length. Along‐wind forces are simulated using the Kaimal wi...
Article
Multimode vibration control of a non-linear building with distributed multiple tuned vibration absorbers (d-MTVAs) is studied to assess its seismic vulnerability. A multi-story building is exposed to earthquakes such that the beams and columns are likely to undergo material non-linearity which could be controlled. The modal properties of the linear...
Article
Full-text available
This paper investigates the effect of considering soil-structure interaction (SSI) in seismic responses of reinforced concrete (RC) chimneys installed by distributed tuned vibration absorbers vertically (d-MTVAs). A multimode control approach is used to design the d-MTVAs. Two-dimensional (2D) RC chimney is the assembly of beam elements. Frequency-...
Article
Full-text available
This review presents an up-to-date account of research in multi-hazard assessment and vibration control of engineering structures. A general discussion of the importance of multi-hazard consideration in structural engineering, as well as recent advances in this area, is presented as a background. In terms of performance assessment and vibration con...
Article
Control algorithms are the most crucial aspects in effective control of civil structures exposed to earthquake forces. Recently, adaptive intelligent control algorithms are evolving to be a viable substitute strategy for conventional model-based control algorithms. One of the most recent developments, known as the Brain Emotional Learning Based Int...
Chapter
Adjacent buildings are exposed to a high risk of pounding against each other during seismic events. In recent strong earthquakes events, the separation gap has been found to be insufficient to prevent structural damage related to pounding phenomena. The inerter-based tuned mass damper has been validated as an effective, lightweight passive control...
Article
Full-text available
Optimal tuned mass damper inerter (TMDI) systems in controlling displacement demands on structures affected by pulse-like near fault ground motions is presented. Simplified mathematical models of three buildings and many recorded near-fault ground motions, all containing a dominant velocity pulse, are used to make this investigation valid for a wid...
Article
Full-text available
This work investigates the efficiency of tuned inerter dampers (TIDs) in controlling seismic response of two adjacent buildings and the pounding distance between them. Pervious research on this subject has shown that installing TIDs in every floor of one of the buildings and coupling each floor of the two buildings with additional inerters (CS1) pr...
Chapter
This study aims to investigate the effect of the vertical component of earthquake excitation on the seismic safety of bridges. Two types of three-dimensional bridges, including an ordinary beam bridge, and a suspension bridge, are modelled, and their seismic performance is evaluated under a set of seismic records. Particular emphasis is placed on n...
Article
Full-text available
Tuned mass damper inerter (TMDI) is commonly reported to be a lightweight tunable device that can significantly reduce buildings' seismic response. However, the backward action produced by the inerter and returned to the building in conventional TMDIs may either reduce the device performance or limit the inerter potential. This study proposes and i...
Article
The paper investigates seismic response control of bridges with nonlinear tuned vibration absorbers (n-TVAs). A three-span continuous bridge is used as case study. The n-TVAs are designed to act in both longitudinal and transverse directions of the bridge. The n-TVAs are modelled as inelastic springs with bilinear hysteretic behavior. A simple and...
Article
Full-text available
Control algorithms are the most critical aspects in the successful control of civil structures subjected to earthquake and wind forces. In recent years, adaptive intelligent control algorithms are emerging as an acceptable substitute method to conventional model-based control algorithms. These algorithms mainly work on the principles of artificial...
Article
Earthquake response control of base-isolated bridges using supplementary passive dampers is presented. A benchmark highway overcrossing located in California is selected to indicate the effectiveness of such hybrid response control schemes. The bridge is modeled as a lumped mass three-dimensional stick model. The coupled differential equations of m...
Chapter
The paper studies the reliability analysis and passive vibration control (PVC) of tall structures with uncertain parameters. A tall structure is modeled using certain parameters, Monte Carlo method is employed to create the uncertain parameters for the selected tall structure. The robust tune-able PVC (TPVC) schemes are installed to mitigate the re...
Conference Paper
Full-text available
System identification of a code conforming low-rise reinforced concrete frame building in Kathmandu, Nepal is reported in this paper. The fundamental vibration period and damping ratio of the building were determined using ambient vibration records taken in three floors of the building. Ambient vibration measurements were taken using three triaxial...
Article
Full-text available
The article investigates response mitigation of a reinforced concrete (RC) chimney subjected to pulse-like near-fault ground motions using tuned mass damper (TMD) schemes. The total height of the chimney is 265 m with a mass of 11,109 ton. Three TMD schemes are used: single tuned mass damper (STMD), multiple TMDs having equal stiffness (w-MTMDs) an...
Article
Full-text available
This study explores the effectiveness of shared tuned mass damper (STMD) in reducing seismic pounding of adjacent buildings. The dynamics of STMDs is explored through numerical simulations of buildings idealized as single and multiple degree of freedom oscillators. An optimization method proposed in the literature is revisited. It is shown that the...
Article
Full-text available
The effectiveness of a tuned mass damper (TMD) in dynamic vibration mitigation of a 20-storey steel benchmark structure (SBB) under real earthquake ground motions is presented. To study the positioning and tuning effect, a TMD is positioned at the largest or relatively larger of the normalized amplitude of mode shape of the selected structure. At e...
Article
Full-text available
Earthquake response mitigation of a base-isolated (BI) building equipped with (i) a single tuned mass damper at the top of the building, (ii) multiple tuned mass dampers (MTMDs) at the top of the building, and (iii) MTMDs distributed on different floors of the building (d-MTMDs) is studied. The shear-type buildings are modeled by considering only o...
Article
Full-text available
Seismic response of a utility-scale land-based wind turbine to near-fault pulse-like ground motions is presented in this study. The structural model corresponds to the 5-MW prototype developed by National Renewable Energy Laboratory. Response parameters such as tower-top displacement, base shear, and overturning moment are calculated by time histor...
Article
The efficiency of tuned mass dampers (TMDs) in along-wind response mitigation of a wind turbine with consideration of blade coupling and soil-structure interaction (SSI) is investigated. The wind turbine tower is modeled as a multi-degree of freedom (MDOF) with three blades are connected as a MDOF system to the tower. The along-wind drag forces are...
Article
Full-text available
This study presents analysis of a benchmark building installed with tuned mass dampers (TMDs) while subjected to wind and earthquake loads. Different TMD schemes are applied to reduce dynamic responses of the building under wind and earthquakes. The coupled equations of motion are formulated and solved using numerical methods. The uncontrolled buil...
Article
The aim of the present study is to investigate the efficiency of the torsional tuned mass dampers (T‐TMDs) in response control of asymmetric buildings under bidirectional earthquake ground excitations. The efficiency of the T‐TMDs is compared with bidirectional tuned mass dampers (BTMDs). The T‐TMDs are oriented to the rotation of the structures ab...
Article
Earthquake response mitigation of base-isolated (BI) buildings with a tuned mass damper (TMD) is investigated. Two-dimensional reinforced concrete buildings having multiple degrees of freedom are numerically modelled. The placement of a TMD is varied on different floor levels and the building response under earthquake excitations is studied. The la...
Article
Dynamic response control of a wind-excited tall building installed with distributed multiple tuned mass dampers (d-MTMDs) is presented. The performance of d-MTMDs is compared with those of single tuned mass damper (STMD) and MTMDs installed at top of the building. The modal frequencies and mode shapes of the building are first determined. Based on...
Article
Seismic response of a base‐isolated building equipped with single tuned mass damper (STMD), multiple tuned mass dampers (MTMDs), and distributed multiple tuned mass dampers (d‐MTMDs) under real earthquake ground motions is investigated. Numerical study is carried out using analytical models of five‐, 10‐, and 15‐storey base‐isolated buildings equip...
Conference Paper
Wind response control of tall building installed with single-tuned mass damper (STMD) and multiple-tuned mass dampers (MTMDs) is presented. The effect of the soil-structure-interaction (SSI) is incorporated to evaluate the performance of the STMD and MTMDs under the along-wind and across-wind forces. The dynamic response of the wind-excited tall bu...
Article
The effectiveness of distributed multiple tuned mass dampers (d-MTMDs) in seismic response control of bridges was investigated. Numerical models were developed for evaluating the seismic response of concrete and steel truss bridges without and with tuned mass damper(s) (TMD(s)) installed. The modal frequencies and mode shapes of the uncontrolled an...
Chapter
Nowadays, improved versions of earthquake response modification devices are being introduced to maximise efficacy in dynamic vibration abatement in structures. Here, hybrid system has been proposed to be used for earthquake response modification of bridges by combined use of two passive devices: base isolation systems and tuned mass absorbers. The...
Article
Full-text available
Robustness in multi-mode control of structures using tuned mass dampers (TMDs) is presented under seismic excitations. The robustness of the distributed multiple TMDs, i.e. d-MTMDs is compared with single TMD (STMD) and with multiple TMDs all installed at the top of the building (MTMDs-all.top). A 20-storey steel benchmark building subjected to ear...
Article
Wind response control of tall buildings installed with a tuned mass damper (TMD) is investigated. The performance of a TMD installed at the topmost floor of a 76-storey benchmark building is compared with the TMD installed at different floors (locations) of the building. The TMD is placed where particular mode shape amplitude of the building is lar...
Article
A state-of-the-art review on the response control of structures mainly using the passive tuned mass damper(s) (TMD/s) is presented. The review essentially focuses on the response control of wind- and earthquake-excited structures and covers theoretical backgrounds of the TMD and research developments therein. To put the TMD within a proper frame of...
Article
Full-text available
Multi-mode wind response control of chimneys on flexible foundation is studied. The multi-mode control is achieved using distributed multiple tuned mass dampers (d-MTMDs). A reinforced concrete (RC) chimney is considered as an assemblage of beam elements, each assumed to have constant diameter over the element length, and soil-structure interaction...
Article
Full-text available
The effect of soil-structure interaction (SSI) on the dynamic responses of seismically isolated three-span continuous reinforced concrete (RC) bridge is investigated. Also, tuned mass damper(s) (TMD/s) is/are installed to control undesirable bearing displacement, even under the SSI effect. The TMDs are placed at the mid-span of the bridge and each...
Conference Paper
The importance of electricity power transmission lines for improving the economy of the Afghanistan is investigated. Electric power transmission line systems are of great importance as structures. Transmission line systems relay the power from production sites to the users. Failure of these structures can lead to power cuts and therefore disrupt th...
Conference Paper
Full-text available
Multi-mode seismic response control of chimneys on flexible foundation is studied. The multi-mode control is achieved using distributed multiple tuned mass dampers (d-MTMDs). A reinforced concrete (RC) chimney is considered as an assemblage of beam elements, each assumed to have constant diameter over the element length, and soil-structure interact...
Article
Effectiveness of distributed tuned mass dampers (d-TMDs) designed according to the mode shapes for multi-mode control of chimneys as against the TMDs placed arbitrarily (ad-TMDs) and single TMD (STMD) under earthquake ground motions is investigated. The investigation includes geometrically regular and irregular chimneys under un-cracked and cracked...
Article
The paper is interesting and the discusser didn’t see any discussion.Threedimensional (3D) analyses of buildings controlled with tuned mass dampers (TMDs) by considering three components of the earthquake ground motion is original contribution. The paper seems to have several issuesin assumptions and modeling. However, the information might not be...
Chapter
The effectiveness of optimal single tuned mass damper (STMD) for wind and earthquake response control of high-rise building is investigated. Two buildings one 76-storey benchmark building and one 20-storey benchmark building are modeled as shear type structure with a lateral degree-of-freedom at each floor, and STMD is installed at top or different...
Article
Full-text available
The effect of viscous, viscoelastic, and friction supplemental dampers on the seismic response of base-isolated building supported by various isolation systems is investigated. Although base-isolated buildings have an advantage in reducing damage to the superstructure, the displacement at the isolation level is large, especially under near-fault gr...
Article
Full-text available
Multiple tuned mass dampers (MTMDs) distributed along height of a high-rise building are investigated for their effectiveness in vibration response control. A 76-storey benchmark building is modeled as shear type structure with a lateral degree of freedom at each floor, and tuned mass dampers (TMDs) are installed at top/different floors. Suitable l...
Article
Full-text available
Wind response control of a 76-storey benchmark building installed with distributed multiple tuned mass dampers (d-MTMDs) is investigated. The performance of the d-MTMDs is compared with all multiple tuned mass dampers (MTMDs) placed at the topmost floor and with single tuned mass damper (STMD) having same total mass. The MTMDs as well as STMD are p...

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