Uncertainty Evaluation for Structural Damage Parameters Prediction Methodology

2004 ◽  
Author(s):  
Eva L. Suarez ◽  
Brice Cassenti ◽  
Richard Holmes ◽  
William Scheuren
Keyword(s):  
Material Property ◽  
Material Characterization ◽  
Structural Damage ◽  
Linear Regression Analysis ◽  
Metal Temperature ◽  
Performance Parameters ◽  
Component Design ◽  
Critical Metal ◽  
Damage Tracking ◽  
Military Mission

Structural component life estimated from damage tracking parameters in real-time are a subject of recent studies. The proposed project consists of determining parametric equations for the structural damage variables, metal temperature and stress, as a function of design performance parameters, exercising these equations through material property algorithms generated as a function of material characterization, and evaluating the uncertainty of the damage accumulated from a simulated military mission. Thermal and structural finite element results obtained during the component design phase were used as the dependent response for the stress and metal temperature equations. The independent variables used in the statistical linear regression analysis were mission performance parameters. A time function was implemented to account for the response time characteristic of the component metal temperature during transient conditions. The material property algorithm combined critical metal temperatures and stresses with probabilistic material capability generated from stochastic material characterization. Validation of the methodology was accomplished by the statistical analysis performed between predicted results and expected values from the design analysis. Uncertainty analysis established the confidence bound about the predicted result.

scholarly journals Damage Diagnosis in 3D Structures Using a Novel Hybrid Multiobjective Optimization and FE Model Updating Framework

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Nizar Faisal Alkayem ◽  
Maosen Cao ◽  
Minvydas Ragulskis
Keyword(s):  
Structural Damage ◽  
Model Updating ◽  
Complex Problem ◽  
Dynamic Responses ◽  
Mode Shapes ◽  
Fe Model ◽  
Modal Strain Energy ◽  
3D Structures ◽  
Multiobjective Particle Swarm Optimization ◽  
Damage Tracking

Structural damage detection is a well-known engineering inverse problem in which the extracting of damage information from the dynamic responses of the structure is considered a complex problem. Within that area, the damage tracking in 3D structures is evaluated as a more complex and difficult task. Swarm intelligence and evolutionary algorithms (EAs) can be well adapted for solving the problem. For this purpose, a hybrid elitist-guided search combining a multiobjective particle swarm optimization (MOPSO), Lévy flights (LFs), and the technique for the order of preference by similarity to ideal solution (TOPSIS) is evolved in this work. Modal characteristics are employed to develop the objective function by considering two subobjectives, namely, modal strain energy (MSTE) and mode shape (MS) subobjectives. The proposed framework is tested using a well-known benchmark model. The overall strong performance of the suggested method is maintained even under noisy conditions and in the case of incomplete mode shapes.

scholarly journals Predictors of Assessment of Spondyloarthritis International Society (ASAS) Health Index in Axial Spondyloarthritis and Comparison of ASAS Health Index between Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis: Data from the Catholic Axial Spondyloarthritis COhort (CASCO)

2019 ◽  
Vol 8 (4) ◽  
pp. 467 ◽  
Author(s):  
Hong Ki Min ◽  
Jennifer Lee ◽  
Ji Hyeon Ju ◽  
Sung-Hwan Park ◽  
Seung-Ki Kwok
Keyword(s):  
Regression Analysis ◽  
Health Status ◽  
Ankylosing Spondylitis ◽  
Alcohol Consumption ◽  
International Society ◽  
Structural Damage ◽  
Axial Spondyloarthritis ◽  
Economic Status ◽  
Linear Regression Analysis ◽  
Health Index

The Assessment of Spondyloarthritis International Society (ASAS) health index (HI) is a novel tool for approaching disability, health, and functioning in spondyloarthritis (SpA). In the present study we compared ASAS HI between patients with ankylosing spondylitis (AS) and those with nonradiographic axial SpA (nr-axSpA). In addition, we identified predictors of ASAS HI. We designed this cross-sectional study using data from the Catholic Axial Spondyloarthritis COhort (CASCO), a prospective cohort from a single tertiary hospital. We compared baseline characteristics, including ASAS HI, between AS and nr-axSpA, and determined the frequency of each item constituting the ASAS HI. We used linear regression analysis to identify factors associated with ASAS HI. Total of 357 patients with axSpA—261 with AS and 96 with nr-axSpA—were included in analysis. AS patients were older and had higher ASAS HI than nr-axSpA. Among ASAS HI items, pain (item No. 1) and energy/drive (item No. 5) were the most common areas for which axSpA patients experienced discomfort. ASAS HI correlated with other SpA-related parameters such as BASDAI, ASDAS, and BASFI. Multivariable regression analysis of the axSpA group showed that high NSAID intake and mSASSS were positively associated with ASAS HI, whereas higher economic status and alcohol consumption were negatively associated with ASAS HI. Results were consistent in the AS group on subgroup analysis, whereas alcohol consumption was the only factor significantly associated with ASAS HI in the nr-axSpA group. In the present cohort study, patients with AS had poorer health status (higher ASAS HI) than those with nr-axSpA. Items proposed by AS patients (items No. 1 and 5) were the most frequently checked areas as axSpA patients feel discomfort, and this support that ASAS HI could practically assess actual discomfort of axSpA patient. ASAS HI was well correlated with known disease parameters, including activity, function, and quality of life; therefore, ASAS HI could be used in the future to represent the health status of SpA in a systematic way. Spinal structural damage (higher mSASSS), high NSAID intake, alcohol consumption, and economic status were predictors of ASAS HI in patients with axSpA, especially those with AS.

Abstract 14298: The Normal Balance Between Antifibrotic Bmp-7 and Profibrotic Tgf-β Signaling is Lost on the Pressure Overload-induced LV Remodeling and Can Be Modified Favorably. A Translational Study

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Francisco Nistal ◽  
David Merino ◽  
Ana V Villar ◽  
Raquel Garcia-Lopez ◽  
Mónica Tramullas ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Structural Damage ◽  
Transforming Growth Factor ◽  
Linear Regression Analysis ◽  
Pressure Overload ◽  
Luciferase Reporter ◽  
Reverse Remodeling ◽  
3T3 Fibroblasts ◽  
Lv Remodeling ◽  
Nih 3T3

Introduction: Cytokynes of the Transforming Growth Factor-β(TGF-β) superfamily are involved in tissue fibrosis: TGF-β promotes fibrosis, whereas Bone Morphogenetic Protein-7 (BMP-7) is antifibrotic. Hypothesis: (i) LV remodeling in the pressure overload condition associates disequilibrium in the cellular signals mediated by these cytokynes; and (ii) BMP-7 exerts beneficial effects on LV remodeling and on reverse remodeling. Methods: We studied patients with aortic stenosis (AS; n=45) and surgical controls (n=30), and mice subjected to transverse aortic constriction (TAC; n=24). LV morphology and function were assessed by echocardiography; LV samples were analyzed by qPCR, immunoblotting and histology. Results: Pressure overload diminished the expression of BMP-7 and its effectors pSmad1/5/8 and increased the ratio TGF-β/BMP-7 in the LV from AS-patients and TAC-mice. BMP-7 expression correlated inversely with collagens, fibronectin and β-myosin heavy chain, with the degree of hypertrophy, and with the severity of diastolic dysfunction, and directly with systolic function. Multiple linear regression analysis disclosed BMP-7 and TGF-β as predictors, negative and positive, respectively, of hypertrophy. BMP-7 prevented the hypertrophic program elicited by TGF-β in cultured cardiomyocytes, and the transcriptional activation of Col1A1 promoter-luciferase reporter in NIH-3T3 fibroblasts. In TAC-mice, BMP-7 gain-of-function attenuated the development of structural damage and dysfunction, halted ongoing remodeling and facilitated reverse remodeling. BMP-7 loss-of-function exerted opposite effects. Luciferase reporter assays in NIH-3T3 fibroblasts suggested that BMP-7 promoted the transcription of the inhibitory Smad7, who in turn has a repressing effect on TGFβ signaling. Accordingly, in AS-patients and TAC-mice, the LV expressions of Smad7 and BMP-7 correlated directly. Conclusion: The disequilibrium between BMP-7 and TGF-β signals plays a relevant role in the pressure overload-induced myocardial remodeling in TAC-mice and AS-patients. We suggest that BMP-7 antagonizes the hypertrophic and profibrogenic effects of TGF-β through a mechanism involving Smad7. Funding: PI12/00999; RD12/0042/0018; RD12/0042/0012.

Comparison of various structural damage tracking techniques based on experimental data

2010 ◽  
Vol 6 (9) ◽  
pp. 1057-1077 ◽  
Author(s):  
Hongwei Huang ◽  
Jann N. Yang ◽  
Li Zhou
Keyword(s):  
Experimental Data ◽  
Structural Damage ◽  
Damage Tracking

scholarly journals Experimental Study of an Adaptive Sequential Nonlinear LSE with Unknown Inputs for Structural Damage Tracking

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Tengfei Mu ◽  
Li Zhou ◽  
Jann N. Yang
Keyword(s):  
Structural Damage ◽  
Experimental Studies ◽  
Structural Safety ◽  
Small Scale ◽  
Physical Parameters ◽  
Damage Scenarios ◽  
Unknown Inputs ◽  
Response Data ◽  
Emergency Event ◽  
Damage Tracking

An improved adaptive sequential nonlinear LSE with unknown inputs (ASNLSE-UI) approach was proposed to real-time-track the structural damage when it occurs for structural safety and management after emergency event. Experimental studies are presented to verify the capability of the improved ASNLSE-UI approach. A series of tests using a small-scale 3-story base-isolated building have been performed. White noise and earthquake excitations, applied to the base of the model, have been used. To simulate structural damages during the test, an innovative device is designed and manufactured to reduce the stiffness of some stories. With the measured response data of different damage scenarios, the improved ASNLSE-UI approach is used to track the variation of structural physical parameters. Besides, the unknown inputs are simultaneously identified. Experimental results demonstrate that the improved ASNLSE-UI approach is capable of tracking the variation of stiffness parameters leading to the detection of structural damages.

scholarly journals Keep Your Head Up—Correlation between Visual Exploration Frequency, Passing Percentage and Turnover Rate in Elite Football Midfielders

Sports ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 139 ◽  
Author(s):  
Ashwin Phatak ◽  
Markus Gruber
Keyword(s):  
Linear Regression ◽  
Turnover Rate ◽  
Linear Regression Analysis ◽  
Team Sports ◽  
Significant Negative Correlation ◽  
Individual Performance ◽  
Visual Exploration ◽  
Performance Parameters ◽  
Training Interventions ◽  
Scan Rate

Statistical analysis of real in-game situations plays an increasing role in talent identification and player recruitment across team sports. Recently, visual exploration frequency (VEF) in football has been discussed as being one of the important performance-determining parameters. However, until now, VEF has been studied almost exclusively in laboratory settings. Moreover, the VEF of individuals has not been correlated with performance parameters in a statistically significant number of top-level players. Thus, the objective of the present study was to examine the relationship between VEF and individual performance parameters in elite football midfielders. Thirty-five midfielders participating in the Euro 2016 championship were analyzed using game video. Their VEF was categorized into scans, transition scans, and total scans. Linear regression analysis was used to correlate the three different VEF parameters with the passing percentage and the turnover rate for individual players. The linear regression showed significant positive correlations between scan rate (p = 0.033, R 2 = 3.0%) and total scan rate (p = 0.015, R 2 = 4.0%) and passing percentage but not between transition scan rate and passing percentage (p = 0.074). There was a significant negative correlation between transition scan rate and turnover rate (p = 0.023, R 2 = 3.5%) but not between total scan rate (p = 0.857) or scan rate (p = 0.817) and turnover rate. In conclusion, the present study shows that players with a higher VEF may complete more passes and cause fewer turnovers. VEF explains up to 4% of variance in pass completion and turnover rate and thus should be considered as one of the factors that can help to evaluate players and identify talents as well as to tailor training interventions to the needs of midfielders up to the highest level of professional football.

An Integrated Analytical Tool on Predicting Structural Responses of Ships Under Collision and Grounding Scenarios

2017 ◽  
Author(s):  
Zijie Song ◽  
Zhiqiang Hu
Keyword(s):  
Energy Dissipation ◽  
Material Property ◽  
Structural Damage ◽  
Plate Thickness ◽  
Cost Effective ◽  
Analytical Tool ◽  
Design Stage ◽  
Structural Responses ◽  
Ship Collision ◽  
Ship Grounding

An integrated analytical tool is introduced in this paper, which can be used to predict the structural responses, including resistance, energy dissipation and structural damage, for the ships under accidental collision and grounding scenarios. On purpose of preventing the disastrous consequences due to ship collision and grounding from happening, it is necessary to predict the structural responses and the event consequences during the structure design stage, and mostly important, in a cost-effective and conveniently using way, that can be accepted by ship structure designers. Analytical prediction method has the advantages of cost-effective and fast-calculation. Therefore, an integrated analytical tool is built to predict ship structural response under collision and grounding accident scenarios. This analytical tool contains two modules, one is ship collision module and the other is ship grounding module. In ship collision module, the scenario of head on striking in a right angle is adopted as the most critical scenario. The major structural properties of the striking vessel and those of the struck vessel can be defined, including ship hull scantling, plate thickness, scantling of stiffeners, striking positions, striking velocity and material property. The shape of the striking ship’s bow can be defined as bulbous bow or raked bow. In ship grounding module, powered grounding is defined as the critical grounding scenario. Scantling of ship bottom structure, plate thickness, scantling of stiffeners, material property, ship grounding velocity, shape of the indenter and the grounding positions are the mandatory input parameters. With the application of the analytical tool, structural resistance, energy dissipation and structural damage can be calculated by a series of analytical equations. These analytical expressions on resistance and energy dissipation come from the related work conducted in SJTU within the past few years. Furthermore, numerical simulations were also conducted with code LS_DYNA, to prove the feasibility of the analytical tool. This integrated analytical tool can tell the structural designer the crashworthiness of the ship under collision and grounding scenario during the structural design stage.

Evaluation of single-electron movies of glutamine synthetase molecules

1983 ◽  
Vol 41 ◽  
pp. 280-281
Author(s):  
W. Kunath ◽  
E. Zeitler ◽  
M. Kessel
Keyword(s):  
Electron Microscope ◽  
Glutamine Synthetase ◽  
Electron Irradiation ◽  
Structural Damage ◽  
Structural Changes ◽  
Single Electron ◽  
Continuous Series ◽  
Digital Recording ◽  
Recording Device ◽  
Low Exposure

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.

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