scholarly journals Time-Dependent Damage Estimation of a High-Rise Steel Building Equipped with Buckling-Restrained Brace under a Series of Earthquakes and Winds

2021 ◽  
Vol 11 (19) ◽  
pp. 9253
Author(s):  
Ahmad Naqi ◽  
Tathagata Roy ◽  
Taiki Saito
Keyword(s):  
Damage Index ◽  
Cumulative Damage ◽  
Structural Elements ◽  
High Rise ◽  
Sequence Of Events ◽  
Design Life ◽  
Steel Building ◽  
Element Approach ◽  
Wind Events ◽  
Plastic Strain Energy

This study investigates the cumulative damage of a 20-story high-rise steel building equipped with buckling-restrained braces (BRB) under the likely occurrence of earthquake and wind events in the design life of the building. The objective of this research is to introduce a method for evaluating the cumulative damage of BRBs under multi-hazard events that are expected to occur during the service life of a high-rise building in order to achieve a safer building. A methodology is proposed using a Poisson point process to estimate the timeline of earthquake and wind events, wherein the events are assumed to be independent in nature. The 20-story high-rise steel building with BRBs is designed according to the Japanese standard and analyzed using the finite element approach, considering nonlinearities in the structural elements and BRBs. The building is analyzed consecutively using the timeline of earthquakes and winds, and the results are compared with those under individual earthquakes and winds. In addition to the responses of the frame such as the floor displacement and acceleration, the damage of BRBs in terms of the damage index, the energy absorption, the plastic strain energy, and the maximum and cumulative ductility factor are evaluated. It is observed that the BRB’s fatigue life under multi-hazard scenarios is a multi-criteria issue that requires more precise investigation. Moreover, the overall building’s performance and BRB’s cumulative damage induced by the sequence of events in the design life of the building is significantly larger than that under an individual event.

Design of a High-Rise Steel Building to Resist Disproportionate Collapse

2014 ◽  
Vol 102 (20) ◽  
pp. 1722-1725
Author(s):  
Karl Rubenacker ◽  
Ramon Gilsanz ◽  
Philip Murray ◽  
Eugene Kim
Keyword(s):  
High Rise ◽  
Disproportionate Collapse ◽  
Steel Building

scholarly journals Development and Validation of a Post-Earthquake Safety Assessment System for High-Rise Buildings Using Acceleration Measurements

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1758
Author(s):  
Koji Tsuchimoto ◽  
Yasutaka Narazaki ◽  
Billie F. Spencer
Keyword(s):  
Safety Assessment ◽  
Large Scale ◽  
Model Updating ◽  
Safety Evaluation ◽  
Assessment System ◽  
Shaking Table ◽  
Structural Safety ◽  
High Rise ◽  
Steel Building ◽  
Earthquake Safety

After a major seismic event, structural safety inspections by qualified experts are required prior to reoccupying a building and resuming operation. Such manual inspections are generally performed by teams of two or more experts and are time consuming, labor intensive, subjective in nature, and potentially put the lives of the inspectors in danger. The authors reported previously on the system for a rapid post-earthquake safety assessment of buildings using sparse acceleration data. The proposed framework was demonstrated using simulation of a five-story steel building modeled with three-dimensional nonlinear analysis subjected to historical earthquakes. The results confirmed the potential of the proposed approach for rapid safety evaluation of buildings after seismic events. However, experimental validation on large-scale structures is required prior to field implementation. Moreover, an extension to the assessment of high-rise buildings, such as those commonly used for residences and offices in modern cities, is needed. To this end, a 1/3-scale 18-story experimental steel building tested on the shaking table at E-Defense in Japan is considered. The importance of online model updating of the linear building model used to calculate the Damage Sensitive Features (DSFs) during the operation is also discussed. Experimental results confirm the efficacy of the proposed approach for rapid post-earthquake safety evaluation for high-rise buildings. Finally, a cost-benefit analysis with respect to the number of sensors used is presented.

Earthquake induced floor accelerations on a high-rise building: Scale model tests on a shaking table

2021 ◽  
Author(s):  
Fabio Rizzo ◽  
Alessandro Pagliaroli ◽  
Giuseppe Maddaloni ◽  
Antonio Occhiuzzi ◽  
Andrea Prota
Keyword(s):  
Soil Structure ◽  
Shaking Table ◽  
Soil Structure Interaction ◽  
Scale Model ◽  
Structural Elements ◽  
Shaking Table Tests ◽  
Building Model ◽  
High Rise ◽  
High Rise Building ◽  
Story Building

<p>The paper discusses results of shaking table tests on an in-scale high-rise building model. The purpose was to calibrate a dynamic numerical model for multi-hazard analyses to investigate the effects of floor acceleration. Accelerations, because of vibration of non-structural elements, affect both the comfort and safety of people. The research investigates the acceleration effects of both seismic and wind forces on an aeroelastic in-scale model of a multi-story building. The paper discusses the first phase of experiments and gives results of floor accelerations induced by several different base seismic impulses. Structural analyses were first performed on the full-scale prototype to take soil-structure interaction into account. Subsequently the scale model was designed through aeroelastic scale laws. Shaking table experiments were then carried out under different base accelerations. The response of the model and, in particular, amplification of effects from base to top are discussed.</p>

In-Service Reliability Assessment of Turbine Blade Thermal Barrier Coatings Based on a Novel Cumulative Damage Index Model

2021 ◽  
Author(s):  
He Liu ◽  
Jianzhong Sun ◽  
Shiying Lei
Keyword(s):  
Damage Index ◽  
Cumulative Damage ◽  
Life Assessment ◽  
Thermal Barrier ◽  
Inlet Temperature ◽  
Service Reliability ◽  
Engine Operation ◽  
Premature Failure ◽  
Covariate Data ◽  
Index Model

Abstract Thermal barrier coating (TBC) has been used widely on turbine blades to provide temperature and oxidation protection. With the turbine inlet temperature continuously increasing, TBCs have become more likely to oxide spallation, leading to premature failure of blade metal substrates. Thus, It is necessary to accurately evaluate the in-service reliability of TBCs for blade life assessment and engine operation safety. Nowadays, it is common to dynamically record aero-engine operating and performance data, called dynamic covariate data, which provides periodic snapshots for obtaining reliability information of engine components. Nevertheless, existing TBC life prediction models that pay adequate attention to dynamic covariate information are rare. This paper focuses on using limited failure samples with associated dynamic covariate data to make in-service reliability assessments of TBCs through a proposed cumulative damage index model. For the demonstration of the proposed approach, an integrated TBC life simulation approach has been introduced, which comprises engine performance, blade thermal, TBC damage, and damage accumulation models. The case study shows that the proposed cumulative damage index model based method provides more stable and accurate results than the traditional statistical method based on failure-time data.

Application of Modular Air-Tuned Damper System in High-Rise Buildings

2019 ◽  
Author(s):  
Sebastian Mendes ◽  
Zhi Zhang ◽  
Pierre Ghisbain ◽  
Marguerite Pinto ◽  
Elisabeth Malsch
Keyword(s):  
Cost Effective ◽  
Tuned Mass Dampers ◽  
Interior Space ◽  
High Rise ◽  
Complex Shapes ◽  
Dynamic Analyses ◽  
Broad Domain ◽  
Wind Events ◽  
Tuned Damper

<p>High-rise buildings are progressively being designed and constructed in increasingly slender and complex shapes. Consequently, excessive wind-induced vibrations of these structures are a growing serviceability concern due to their flexibility. Tuned mass dampers (TMDs) are regularly incorporated into high-rise buildings for mitigating excessive wind-induced vibrations. However, traditional TMDs are only effective over a narrow domain of frequencies, require an immense mass and occupy a significant volume of interior space. A novel modular air-tuned damper system was developed which is more cost-effective and flexible in distributing its mass throughout a building to make efficient use of unused space. Importantly, the air-tuned damper system is capable of being tuned across a broad domain of frequencies to more effectively alleviate wind-induced vibrations. This paper presents a case study demonstrating the performance of a high-rise building under 1- year and 10-year wind events whilst equipped with the air-tuned damper system. Dynamic analyses were performed for evaluating the reductions of the building’s lateral accelerations considering different air-tuned damper configurations. The performance of the building under the different damper configurations is discussed.</p>

The Motion Formalism for Flexible Multibody Systems

2021 ◽  
Author(s):  
Olivier Bauchau ◽  
Valentin Sonneville
Keyword(s):  
Multibody Systems ◽  
Equations Of Motion ◽  
Solution Process ◽  
Flexible Multibody Systems ◽  
Structural Elements ◽  
Governing Equations ◽  
Euclidean Group ◽  
Reduced Order ◽  
Flexible Multibody ◽  
Element Approach

Abstract This paper describes a finite element approach to the analysis of flexible multibody systems. It is based on the motion formalism that (1) uses configuration and motion to describe the kinematics of flexible multibody systems, (2) recognizes that these are members of the Special Euclidean group thereby coupling their displacement and rotation components, and (3) resolves all tensors components in local frames. The goal of this review paper is not to provide an in-depth derivation of all the elements found in typical multibody codes but rather to demonstrate how the motion formalism (1) provides a theoretical framework that unifies the formulation of all structural elements, (2) leads to governing equations of motion that are objective, intrinsic, and present a reduced order of nonlinearity, (3) improves the efficiency of the solution process, and (4) prevents the occurrence of singularities.

The interpretation of cumulative damage from the building response observed in Mexico City during the 19 September 2017 earthquake

2020 ◽  
Vol 36 (2_suppl) ◽  
pp. 199-212
Author(s):  
Mario E Rodriguez
Keyword(s):  
Mexico City ◽  
Damage Index ◽  
Seismic Damage ◽  
Building Codes ◽  
Cumulative Damage ◽  
Severe Damage ◽  
Significant Damage ◽  
Building Behavior ◽  
Observed Damage

This work evaluates the damage to and collapse of a set of buildings in the September 2017 earthquake in Mexico City; these buildings were also subjected to the September 1985 Mexico City earthquake. These buildings were located in the area of the highest rate of damage or collapse in 1985, but buildings exhibiting significant damage or collapse in 2017 did not possess any retrofitting. The spectral demands for these buildings, based on typical records registered in the earthquakes of 1985 and 2017, were not much different, suggesting the need to explain why the buildings that collapsed suffered severe damage in 2017 but not in 1985. This building behavior was analyzed using a seismic damage index Id, previously proposed by the author, which considers the effect of cumulative damage. The results indicated that the observed damage to and collapse of these buildings in the September 2017 earthquake can be explained by the effect of cumulative seismic damage. Recommendations are given for possible improvements to the seismic building codes in Mexico.

Comparative study on seismic performance of specially shaped RC columns with that of rectangular columns in high-rise structures

2019 ◽  
Vol 11 (2) ◽  
pp. 202-215
Author(s):  
Shanmukha Shetty ◽  
Subrahmanya R.M. ◽  
Sushanth Bhandary ◽  
Thushar Shetty
Keyword(s):  
Pushover Analysis ◽  
Geometrical Shape ◽  
Structural Elements ◽  
Base Shear ◽  
Percent Reduction ◽  
Rc Columns ◽  
Content Type ◽  
High Rise ◽  
Rc Frames ◽  
Rectangular Columns

Purpose Columns are structural elements that are predominantly subjected to compressive forces and moments that are to be transferred from the super-structure to the sub-structure. The geometrical shape of a column is a significant factor to be considered. The paper aims to discuss this issue. Design/methodology/approach Pushover analysis is carried out, to study the behavior of RC frames with rectangular and specially shaped columns for the same building layout. Findings Reduction of 27.3 percent in base shear, 67.4 percent in spectral displacement, 66.5 percent reduction in storey displacement, 70.22 percent in storey drift and 0.315 percent reduction in storey shear is observed. Practical implications Special shaped RC columns can effectively enhance the structural behavior of high rise structures under seismic excitation in comparison to those with regular shaped RC columns. Originality/value Applications of special shaped columns in structures have showed a great deal of reduction in displacement and shear forces developed due to seismic activity, for the same area of concrete and steel as in rectangular columns.

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