Full-Scale Structural and Nonstructural Building System Performance during Earthquakes: Part II – NCS Damage States

2016 ◽  
Vol 32 (2) ◽  
pp. 771-794 ◽  
Author(s):  
Elide Pantoli ◽  
Michelle C. Chen ◽  
Xiang Wang ◽  
Rodrigo Astroza ◽  
Hamed Ebrahimian ◽  
...  
Keyword(s):  
Full Scale ◽  
System Level ◽  
Economic Losses ◽  
Shake Table Tests ◽  
Nonstructural Components ◽  
Financial Investment ◽  
Nonstructural Systems ◽  
Damage States ◽  
Broad Variety ◽  
Unique Dataset

Nonstructural components and systems (NCSs) provide little to no load bearing capacity to a building; however, they are essential to support its operability. As a result, 75–85% of the initial building financial investment is associated with these elements. The vulnerability of NCSs even during low intensity earthquakes is repeatedly exposed, resulting in large economic losses, disruption of building functionality, and concerns for life safety. This paper describes and classifies damage to NCSs observed during landmark shake table tests of a full-scale five-story reinforced concrete building furnished with a broad variety of NCSs. This system-level test program provides a unique dataset due to the completeness and complexity of the investigated NCSs. Results highlight that the interactions between disparate nonstructural systems, in particular displacement compatibility, as well as the interactions between the NCSs and the building structure often govern their seismic performance.

scholarly journals Learning Damage Representations with Sequence-to-Sequence Models

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 452
Author(s):  
Qun Yang ◽  
Dejian Shen
Keyword(s):  
Damage Detection ◽  
Health Monitoring ◽  
Research Community ◽  
Regions Of Interest ◽  
Data Driven ◽  
Economic Losses ◽  
Shake Table ◽  
Learning Models ◽  
Shake Table Tests ◽  
Damage States

Natural hazards have caused damages to structures and economic losses worldwide. Post-hazard responses require accurate and fast damage detection and assessment. In many studies, the development of data-driven damage detection within the research community of structural health monitoring has emerged due to the advances in deep learning models. Most data-driven models for damage detection focus on classifying different damage states and hence damage states cannot be effectively quantified. To address such a deficiency in data-driven damage detection, we propose a sequence-to-sequence (Seq2Seq) model to quantify a probability of damage. The model was trained to learn damage representations with only undamaged signals and then quantify the probability of damage by feeding damaged signals into models. We tested the validity of our proposed Seq2Seq model with a signal dataset which was collected from a two-story timber building subjected to shake table tests. Our results show that our Seq2Seq model has a strong capability of distinguishing damage representations and quantifying the probability of damage in terms of highlighting the regions of interest.

Full-Scale Structural and Nonstructural Building System Performance during Earthquakes: Part I – Specimen Description, Test Protocol, and Structural Response

2016 ◽  
Vol 32 (2) ◽  
pp. 737-770 ◽  
Author(s):  
Michelle C. Chen ◽  
Elide Pantoli ◽  
Xiang Wang ◽  
Rodrigo Astroza ◽  
Hamed Ebrahimian ◽  
...  
Keyword(s):  
System Performance ◽  
Structural Response ◽  
Companion Paper ◽  
Full Scale ◽  
Experimental Program ◽  
Test Protocol ◽  
Nonstructural Components ◽  
Electrical Systems ◽  
Concrete Building ◽  
Broad Variety

A landmark experimental program was conducted to advance the understanding of nonstructural system performance during earthquakes. The centerpiece of this effort involved shake table testing a full-scale five-story reinforced concrete building furnished with a broad variety of nonstructural components and systems (NCSs) including complete and operable egress, mechanical and electrical systems, facades, and architectural layouts. The building-NCS system was subjected to a suite of earthquake motions of increasing intensity, while base-isolated and then fixed at its base. In this paper, the major components of the test specimen, including the structure and its NCSs, the monitoring systems, and the seismic test protocol are described in detail. Important response and damage characteristics of the structure are also presented. A companion paper describes the damage observed for the various NCSs and correlates these observations with the structure's response.

Experimental study on fire resistance of a full-scale composite floor assembly in a two-story steel framed building

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lisa Choe ◽  
Selvarajah Ramesh ◽  
Xu Dai ◽  
Matthew Hoehler ◽  
Matthew Bundy
Keyword(s):  
Natural Gas ◽  
Fire Resistance ◽  
Full Scale ◽  
System Level ◽  
Compartment Fire ◽  
Content Type ◽  
Standard Fire ◽  
Fire Experiment ◽  
The Usa ◽  
Floor System

PurposeThe purpose of this paper is to report the first of four planned fire experiments on the 9.1 × 6.1 m steel composite floor assembly as part of the two-story steel framed building constructed at the National Fire Research Laboratory.Design/methodology/approachThe fire experiment was aimed to quantify the fire resistance and behavior of full-scale steel–concrete composite floor systems commonly built in the USA. The test floor assembly, designed and constructed for the 2-h fire resistance rating, was tested to failure under a natural gas fueled compartment fire and simultaneously applied mechanical loads.FindingsAlthough the protected steel beams and girders achieved matching or superior performance compared to the prescribed limits of temperatures and displacements used in standard fire testing, the composite slab developed a central breach approximately at a half of the specified rating period. A minimum area of the shrinkage reinforcement (60 mm2/m) currently permitted in the US construction practice may be insufficient to maintain structural integrity of a full-scale composite floor system under the 2-h standard fire exposure.Originality/valueThis work was the first-of-kind fire experiment conducted in the USA to study the full system-level structural performance of a composite floor system subjected to compartment fire using natural gas as fuel to mimic a standard fire environment.

Shake-Table Tests of a Full-Scale Three-Story Reinforced Masonry Shear Wall Structure

2016 ◽  
Vol 142 (10) ◽  
pp. 04016074 ◽  
Author(s):  
A. Stavridis ◽  
F. Ahmadi ◽  
M. Mavros ◽  
P. B. Shing ◽  
R. E. Klingner ◽  
...  
Keyword(s):  
Shear Wall ◽  
Full Scale ◽  
Wall Structure ◽  
Shake Table ◽  
Shake Table Tests ◽  
Reinforced Masonry ◽  
Masonry Shear Wall

Assessment of Earthquake Performance of Structures by Hybrid Simulation

2019 ◽  
Author(s):  
Amr Elnashai ◽  
Hussam Mahmoud
Keyword(s):  
Earthquake Engineering ◽  
Structural Engineering ◽  
Failure Modes ◽  
Experimental Testing ◽  
Hybrid Simulation ◽  
Element Model ◽  
Simulation Software ◽  
Full Scale ◽  
System Level ◽  
Resilient Infrastructure

With current rapid growth of cities and the move toward the development of both sustainable and resilient infrastructure systems, it is vital for the structural engineering community to continue to improve their knowledge in earthquake engineering to limit infrastructure damage and the associated social and economic impacts. Historically, the development of such knowledge has been accomplished through the deployment of analytical simulations and experimental testing. Experimental testing is considered the most accurate tool by which local behavior of components or global response of systems can be assessed, assuming the test setup is realistically configured and the experiment is effectively executed. However, issues of scale, equipment capacity, and availability of research funding continue to hinder full-scale testing of complete structures. On the other hand, analytical simulation software is limited to solving specific type of problems and in many cases fail to capture complex behaviors, failure modes, and collapse of structural systems. Hybrid simulation has emerged as a potentially accurate and efficient tool for the evaluation of the response of large and complex structures under earthquake loading. In hybrid (experiment-analysis) simulation, part of a structural system is experimentally represented while the rest of the structure is numerically modeled. Typically, the most critical component is physically represented. By combining a physical specimen and a numerical model, the system-level behavior can be better quantified than modeling the entire system purely analytically or testing only a component. This article discusses the use of hybrid simulation as an effective tool for the seismic evaluation of structures. First, a chronicled development of hybrid simulation is presented with an overview of some of the previously conducted studies. Second, an overview of a hybrid simulation environment is provided. Finally, a hybrid simulation application example on the response of steel frames with semi-rigid connections under earthquake excitations is presented. The simulations included a full-scale physical specimen for the experimental module of a connection, and a 2D finite element model for the analytical module. It is demonstrated that hybrid simulation is a powerful tool for advanced assessment when used with appropriate analytical and experimental realizations of the components and that semi-rigid frames are a viable option in earthquake engineering applications.

Fast Multiphysics MEMS Simulation With Arnoldi Model Order Reduction

2008 ◽  
Author(s):  
David Binion ◽  
Xiaolin Chen
Keyword(s):  
Model Order Reduction ◽  
Krylov Subspace ◽  
Order Reduction ◽  
Full Scale ◽  
Solution Time ◽  
System Level ◽  
Computational Time ◽  
Mems Devices ◽  
Model Order ◽  
Reduced Order

Modeling and simulation of Micro Electro Mechanical Systems has become increasingly important as the complexity of MEMS devices increases. In particular, thermal effects on MEMS devices has become a growing topic of interest. Through the FEA, detailed solutions can be obtained to investigate the multiphysics coupling and the transient behavior of a MEMS device at the component level. For system-level integration and simulation, the FEA discretization often results in large full-scale models, which can be computationally demanding or even prohibitive to solve. Model order reduction (MOR) was investigated in this study to reduce problem size for complex dynamic system modeling. The Arnoldi method was implemented for MOR to improve the computational efficiency while preserving the input-output behavior of coupled MEMS simulation. Using this method, a low dimensional Krylov subspace was extracted from the full-scale system model. Reduced order solution of the transient temperature distributions was then determined by projecting the system onto the extracted Krylov subspace and solving the reduced system. An electro thermal MEMS actuator was studied for various inputs. To compare results, the full-scale analyses were performed using the commercial FEA program ANSYS. It was found that the computational time of MOR was only a fraction of the full-scale solution time, with the relative errors ranging from 1.1% to 4.5% at different positions on the actuator. Our results show that the reduced order modeling via Alnoldi can significantly decrease the transient analysis solution time without much loss in accuracy for coupled-field MEMS simulation.

Probabilistic Seismic Loss Analysis for the Design of Steel Structures: Optimizing for Multiple-Objective Functions

2016 ◽  
Vol 32 (3) ◽  
pp. 1587-1605 ◽  
Author(s):  
Sanaz Saadat ◽  
Charles V. Camp ◽  
Shahram Pezeshk
Keyword(s):  
United States ◽  
Structural Response ◽  
Time History ◽  
Steel Structure ◽  
Steel Structures ◽  
Earthquake Hazard ◽  
Economic Losses ◽  
Structural System ◽  
Nonstructural Components ◽  
Central United States

An optimized seismic performance-based design (PBD) methodology considering structural and nonstructural system performance and seismic losses is considered to optimize the design of a steel structure. Optimization objectives are to minimize the initial construction cost associated with the weight of the structural system and the expected annual loss (EAL), considering direct economic losses. A non-dominated sorting genetic algorithm method is implemented for the multi-objective optimization. Achieving the desired confidence levels in meeting performance objectives of interest are set as constraints of the optimization problem. Inelastic time history analysis is used to evaluate structural response under different levels of earthquake hazard to obtain engineering demand parameters. Hazus fragility functions are employed for obtaining the damage probabilities for the structural system and nonstructural components. The optimized designs and losses are compared for the structure located in two geographic locations: one in the central United States and another in the western United States.

DDBD assessment of steel CBFs using full scale shake table tests with realistic connections

2019 ◽  
Vol 154 ◽  
pp. 14-26 ◽  
Author(s):  
S. Salawdeh ◽  
T. Ryan ◽  
B.M. Broderick ◽  
J. Goggins
Keyword(s):  
Full Scale ◽  
Shake Table ◽  
Shake Table Tests
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