scholarly journals On Railroad Tank Car Puncture Performance: Part II — Estimating Metrics

2016 ◽  
Author(s):  
David Y. Jeong ◽  
Michael E. Carolan ◽  
Benjamin Perlman
Keyword(s):  
Structural Damage ◽  
Performance Metrics ◽  
Hazardous Materials ◽  
Point Of View ◽  
Structural Performance ◽  
Regulatory Agencies ◽  
Puncture Resistance ◽  
Mathematical Relationships ◽  
Design Factors ◽  
Probabilistic Point

This paper is the second in a two-part series on the puncture performance of railroad tank cars carrying hazardous materials in the event of an accident. Various metrics are often mentioned in the open literature to characterize the structural performance of tank cars under accident loading conditions. One of the consequences in terms of structural damage to the tank during accidents is puncture. This two-part series of papers focuses on four metrics to quantify the performance of tank cars against the threat of puncture: (1) speed, (2) force, (3) energy, and (4) conditional probability of release. In Part I, generalized tank car impact scenarios were illustrated. Particular focus is given to the generalized shell impact scenario because performance-based requirements for shell puncture resistance are being considered by the regulatory agencies in United States and Canada. Definitions for the four performance metrics were given. Physical and mathematical relationships among these metrics were outlined. Strengths and limitations of these performance metrics were discussed. In this paper (Part II), the multi-disciplinary approach to develop engineering tools to estimate the performance metrics is described. The complementary connection between testing and modeling is emphasized. Puncture performance metrics, which were estimated from other sources, are compared for different tank car designs. These comparisons are presented to interpret the metrics from a probabilistic point of view. In addition, sensitivity of the metrics to the operational and design factors is examined qualitatively.

scholarly journals On Railroad Tank Car Puncture Performance: Part I — Considering Metrics

2016 ◽  
Author(s):  
David Y. Jeong ◽  
Benjamin Perlman ◽  
Karl Alexy ◽  
Francisco González
Keyword(s):  
Structural Damage ◽  
Performance Metrics ◽  
Hazardous Materials ◽  
Point Of View ◽  
Structural Performance ◽  
Regulatory Agencies ◽  
Puncture Resistance ◽  
Mathematical Relationships ◽  
Design Factors ◽  
Probabilistic Point

This paper is the first in a two-part series on the puncture performance of railroad tank cars carrying hazardous materials in the event of an accident. Various metrics are often mentioned in the open literature to characterize the structural performance of tank cars under accident loading conditions. One of the consequences in terms of structural damage to the tank during accidents is puncture. This two-part series of papers focuses on four metrics to quantify the performance of tank cars against the threat of puncture: (1) speed, (2) force, (3) energy, and (4) conditional probability of release. In this paper (Part I), generalized tank car impact scenarios are illustrated. Particular focus is given to the generalized shell impact scenario because performance-based requirements for shell puncture resistance are being considered by the regulatory agencies in United States and Canada. Definitions for the four performance metrics are given. Physical and mathematical relationships among these metrics are outlined. Strengths and limitations of these performance metrics are discussed. In Part II, the multi-disciplinary approach to develop engineering tools to estimate the performance metrics will be described. The complementary connection between testing and modeling will be emphasized. Puncture performance metrics, which were estimated from other sources, will be compared for different tank car designs. These comparisons will be presented to interpret the metrics from a probabilistic point of view. In addition, sensitivity of the metrics to the operational and design factors will be examined qualitatively.

Practical IMP Performance Metrics

2016 ◽  
Author(s):  
Jeremiah P. Konell ◽  
Jack Van Schenck ◽  
Joseph P. Bratton ◽  
Steven J. Polasik
Keyword(s):  
Quality Assurance ◽  
Performance Metrics ◽  
Cost Benefit ◽  
Operational Risk ◽  
Hazardous Materials ◽  
Regulatory Agencies ◽  
Private Companies ◽  
Non Profit ◽  
Job Roles ◽  
The Public

Annually or as events occur, operators submit data to various regulatory agencies about the operation, maintenance and extent of their assets. Many of these figures are used by the public, non-profit organizations and private companies to independently conduct assessments about operators, ranging from safety to quality assurance to scope and nature of product deliveries. The Pipeline Hazardous Materials Safety Administration (PHMSA), the National Energy Board (NEB), and other industry organizations have recently put an emphasis on more meaningful metrics by releasing guidelines and leading discussions at industry conferences and workshops. In order to derive more strategic accuracy and pertinence, Explorer Pipeline Company (Explorer) and Det Norske Veritas (U.S.A.), Inc. (DNV GL) have developed a procedural effort to develop meaningful metrics. Several derivative benefits come from this effort such as support for calculating cost-benefit / ROI figures for maintenance projects, justification for compliance-plus activities and, most importantly, a more informed perspective of operational risk. A renewed approach to this effort is to organize the more meaningful factors into three categories: (1) Metrics of job roles and tasks within Explorer’s Asset Integrity staff, (2) Other existing influential metrics (3) Regulatory metrics. Using this approach, Explorer defined well-targeted, unitized metrics, each with a meaningful basis. Explorer anticipates the development of these more meaningful metrics to support the transparency sought by regulators and other stakeholders, benchmark and continually evaluate our Asset Integrity program and possibly support the development of practical metrics for the pipeline industry.

Selection of Materials and Sensors for Health Monitoring of Composite Structures

2003 ◽  
Vol 785 ◽  
Author(s):  
Seth S. Kessler ◽  
S. Mark Spearing
Keyword(s):  
Health Monitoring ◽  
Lamb Wave ◽  
Composite Structures ◽  
Structural Damage ◽  
Performance Metrics ◽  
Full Range ◽  
Transportation Systems ◽  
Health Monitoring Systems ◽  
The Relationship ◽  
Selection Of

ABSTRACTEmbedded structural health monitoring systems are envisioned to be an important component of future transportation systems. One of the key challenges in designing an SHM system is the choice of sensors, and a sensor layout, which can detect unambiguously relevant structural damage. This paper focuses on the relationship between sensors, the materials of which they are made, and their ability to detect structural damage. Sensor selection maps have been produced which plot the capabilities of the full range of available sensor types vs. the key performance metrics (power consumption, resolution, range, sensor size, coverage). This exercise resulted in the identification of piezoceramic Lamb wave transducers as the sensor of choice. Experimental results are presented for the detailed selection of piezoceramic materials to be used as Lamb wave transducers.

scholarly journals Exceedance of design actions in epicentral areas: insights from the ShakeMap envelopes for the 2016–2017 central Italy sequence

2021 ◽  
Author(s):  
Iunio Iervolino ◽  
Pasquale Cito ◽  
Chiara Felicetta ◽  
Giovanni Lanzano ◽  
Antonio Vitale
Keyword(s):  
Earthquake Engineering ◽  
Structural Damage ◽  
Structural Engineering ◽  
Central Italy ◽  
Civil Defense ◽  
Point Of View ◽  
Seismic Sequence ◽  
Ground Shaking ◽  
Motion Effect ◽  
Observed Damage

AbstractShakeMap is the tool to evaluate the ground motion effect of earthquakes in vast areas. It is useful to delimit the zones where the shaking is expected to have been most significant, for civil defense rapid response. From the earthquake engineering point of view, it can be used to infer the seismic actions on the built environment to calibrate vulnerability models or to define the reconstruction policies based on observed damage vs shaking. In the case of long-lasting seismic sequences, it can be useful to develop ShakeMap envelopes, that is, maps of the largest ground intensity among those from the ShakeMap of (selected) events of a seismic sequence, to delimit areas where the effects of the whole sequence have been of structural engineering relevance. This study introduces ShakeMap envelopes and discusses them for the central Italy 2016–2017 seismic sequence. The specific goals of the study are: (i) to compare the envelopes and the ShakeMap of the main events of the sequence to make the case for sequence-based maps; (ii) to quantify the exceedance of design seismic actions based on the envelopes; (iii) to make envelopes available for further studies and the reconstruction planning; (iv) to gather insights on the (repeated) exceedance of design seismic actions at some sites. Results, which include considerations of uncertainty in ShakeMap, show that the sequence caused exceedance of design hazard in thousands of square kilometers. The most relevant effects of the sequence are, as expected, due to the mainshock, yet seismic actions larger than those enforced by the code for structural design are found also around the epicenters of the smaller magnitude events. At some locations, the succession of ground-shaking that has excited structures, provides insights on structural damage accumulation that has likely taken place; something that is not accounted for explicitly in modern seismic design. The envelopes developed are available as supplemental material.

Nonlinear Time-Series Prediction with Missing and Noisy Data

1998 ◽  
Vol 10 (3) ◽  
pp. 731-747 ◽  
Author(s):  
Volker Tresp ◽  
Reimar Hofmann
Keyword(s):  
Time Series ◽  
Stochastic Simulation ◽  
Time Series Prediction ◽  
Noisy Data ◽  
Nonlinear Time Series ◽  
Point Of View ◽  
Data Set ◽  
Sunspot Data ◽  
Error Bars ◽  
Probabilistic Point

We derive solutions for the problem of missing and noisy data in nonlinear time-series prediction from a probabilistic point of view. We discuss different approximations to the solutions—in particular, approximations that require either stochastic simulation or the substitution of a single estimate for the missing data. We show experimentally that commonly used heuristics can lead to suboptimal solutions. We show how error bars for the predictions can be derived and how our results can be applied to K-step prediction. We verify our solutions using two chaotic time series and the sunspot data set. In particular, we show that for K-step prediction, stochastic simulation is superior to simply iterating the predictor.

Anisotropic diffusion based denoising on concrete images and surface crack segmentation

2019 ◽  
Vol 11 (3) ◽  
pp. 395-409
Author(s):  
Diana Andrushia ◽  
N. Anand ◽  
Prince Arulraj
Keyword(s):  
Health Monitoring ◽  
Anisotropic Diffusion ◽  
Structural Damage ◽  
Performance Metrics ◽  
Research Work ◽  
Structural Similarity ◽  
Structural Defects ◽  
Content Type ◽  
Diffusion Filter ◽  
Anisotropic Diffusion Filter

Purpose Health monitoring of concrete is one of the important tasks in the structural health monitoring. The life of any infrastructure relies on the quality of the concrete. The computer vision-based methods are very useful to identify the structural defects. The identification of minor cracks in the noisy concrete image is complex. The purpose of this paper is to denoise the concrete crack images and also segment the cracks. Design/methodology/approach The novelty of the proposed work lies on the usage of anisotropic diffusion filter in the noisy concrete images. Initially anisotropic diffusion filter is applied to smoothen the concrete images. Adaptive threshold and gray level-based edge stopping constant are used in the diffusion process. The statistical six sigma-based method is utilized to segment the cracks from smoothened concrete images. Findings The proposed method is compared with five state-of-the-art-methods with the performance metrics of mean square error, peak signal to noise ratio and mean structural similarity. The experimental results highlight the advantages of the proposed method. Originality/value The novelty of the proposed work lies on the usage of anisotropic diffusion filter in the noisy concrete images. This research work gives the scope for structural damage evaluation by the automation techniques.

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