Qualification of S-N Curve by Experiments: Estimation of Survival Probability for a Low Number of Experiments

2015 ◽  
Author(s):  
Philippe Thibaux ◽  
Cristina Tonesi
Keyword(s):  
Confidence Level ◽  
Fatigue Testing ◽  
Probability Of Failure ◽  
Mean Value ◽  
Load Level ◽  
Experimental Results ◽  
Test Results ◽  
Survival Estimation ◽  
The Mean ◽  
The Cost

Due to the cost of fatigue testing, qualification of new weld details or improved welding techniques is often performed by comparing the experimental results with a mean S-N curve. The experimental dataset is considered to qualify for a given S-N curve if the mean of the log of the experimental results is larger than the mean of the chosen S-N curve plus an interval depending on the chosen confidence level. The confidence level is generally chosen arbitrary high, typically 75% or 90%. The survival estimation does not take into account the risk incurred by the fact that the actual mean has a probability of 25% or 10% of being lower than the theoretical S-N curve. In the present paper, we propose a different methodology based on the design S-N curve. The probability of failure for a given load level is computed by combining the probability of failure considering the mean value of the S-N curve, and the probability of this mean value. Thanks to the present method it is possible to estimate the probability of failure without making an assumption on the confidence level, which reduces the arbitrary during the estimation of the test results, particularly when the number of experimental results is limited.

Research on the Calculation Method for Bending Rigidity of Recycled Concrete Beams

2014 ◽  
Vol 919-921 ◽  
pp. 1396-1399
Author(s):  
Bin Lei ◽  
Hui Wu ◽  
Yu Song Yan ◽  
Chun Hua Rao
Keyword(s):  
Calculation Method ◽  
Concrete Beams ◽  
Mean Value ◽  
Recycled Concrete ◽  
Experimental Results ◽  
Variation Coefficient ◽  
Bending Test ◽  
Test Results ◽  
Bending Rigidity ◽  
The Mean

The comparison between the experimental results of bending rigidity of recycled concrete collected from the bending test carried out by domestic and overseas researchers and the calculated results by formulas from available codes is done. The results show that formulations of from available codes are not suitable for recycled concrete beams. Then, based on the factors that influence the bending rigidity of recycled concrete beams, the formulation of bending rigidity for recycled concrete beams is proposed by theory. The experimental results by this the formulation and the test results is very close, the mean value and variation coefficient of the ratio of experimental value and calculated value for recycled concrete beams is respectively 1.01 and 0.16.Keywords: recycled concrete beams;bending rigidity; deflection; formulation

scholarly journals Evaluation of Bearing Capacity of Strip Footing Using Random Layers Concept

2015 ◽  
Vol 37 (3) ◽  
pp. 31-39 ◽  
Author(s):  
Marek Kawa ◽  
Dariusz Łydżba
Keyword(s):  
Monte Carlo ◽  
Bearing Capacity ◽  
Failure Mechanism ◽  
Design Theory ◽  
Cohesive Soil ◽  
Probability Of Failure ◽  
Mean Value ◽  
Strip Footing ◽  
Random Field Theory ◽  
The Mean

Abstract The paper deals with evaluation of bearing capacity of strip foundation on random purely cohesive soil. The approach proposed combines random field theory in the form of random layers with classical limit analysis and Monte Carlo simulation. For given realization of random the bearing capacity of strip footing is evaluated by employing the kinematic approach of yield design theory. The results in the form of histograms for both bearing capacity of footing as well as optimal depth of failure mechanism are obtained for different thickness of random layers. For zero and infinite thickness of random layer the values of depth of failure mechanism as well as bearing capacity assessment are derived in a closed form. Finally based on a sequence of Monte Carlo simulations the bearing capacity of strip footing corresponding to a certain probability of failure is estimated. While the mean value of the foundation bearing capacity increases with the thickness of the random layers, the ultimate load corresponding to a certain probability of failure appears to be a decreasing function of random layers thickness.

scholarly journals An improved transmitter system to accurately measure wet-bulb temperature of air

2019 ◽  
Vol 52 (7-8) ◽  
pp. 1002-1007
Author(s):  
Liangwen Yan ◽  
Peng Yu ◽  
Sijung Hu ◽  
Qiu Gao ◽  
Wei Li ◽  
...  
Keyword(s):  
Real Time ◽  
Latent Heat ◽  
Measurement Accuracy ◽  
Cost Effective ◽  
Mean Value ◽  
Experimental Results ◽  
Iteration Algorithm ◽  
Good Consistency ◽  
The Mean ◽  
Good Agreement

A cost-effective measurement of wet-bulb temperature of air has great benefits to fulfill a growing demand of industry, cultivation agriculture, and medication. Applying an appropriate algorithm to wet-bulb temperature of air measurement can effectively improve the accuracy and speed of its measurement. The study aims to research how an improved transmitter system along with the latent heat–based iteration algorithm is used to precisely measure wet-bulb temperature of air. The work consists of (1) simulation of the iteration algorithm and (2) validation via experimental protocol. The simulation results through latent heat–based iteration algorithm were in good agreement ( R2≥ 0.99) with the reference. The performance of the improved wet-bulb temperature of air transmitter system was tested by a latent heat–based iteration algorithm experimental setup. The experimental results demonstrate that the improved wet-bulb temperature of air in a good consistency with commercial wet-bulb temperature of air in a range of temperature (15°C–34°C) and relative humidity (28.8%–76.2%). The Bland–Altman plot also shows that the mean value and the standard deviation of the differences between these two systems are 0.14°C and 0.29°C, respectively, which indicates that the improved wet-bulb temperature of air has a good agreement as well. Compared with the commercial wet-bulb temperature of air transmitter system, an advanced processor (STM32F103C8T6) and real-time operating system was applied in the improved wet-bulb temperature of air transmitter system. The experimental results show that its measurement accuracy is closer to the previous study. This study provides an alternative and cost-effective solution to accurately and real-time measure wet-bulb temperature of air.

Design Sensitivity Method for Sampling-Based RBDO With Varying Standard Deviation

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Hyunkyoo Cho ◽  
K. K. Choi ◽  
Ikjin Lee ◽  
David Lamb
Keyword(s):  
Standard Deviation ◽  
Design Variable ◽  
Score Function ◽  
Random Variable ◽  
Probability Of Failure ◽  
Design Sensitivity ◽  
Mean Value ◽  
Reliability Based Design ◽  
The Mean ◽  
Sensitivity Method

Conventional reliability-based design optimization (RBDO) uses the mean of input random variable as its design variable; and the standard deviation (STD) of the random variable is a fixed constant. However, the constant STD may not correctly represent certain RBDO problems well, especially when a specified tolerance of the input random variable is present as a percentage of the mean value. For this kind of design problem, the STD of the input random variable should vary as the corresponding design variable changes. In this paper, a method to calculate the design sensitivity of the probability of failure for RBDO with varying STD is developed. For sampling-based RBDO, which uses Monte Carlo simulation (MCS) for reliability analysis, the design sensitivity of the probability of failure is derived using a first-order score function. The score function contains the effect of the change in the STD in addition to the change in the mean. As copulas are used for the design sensitivity, correlated input random variables also can be used for RBDO with varying STD. Moreover, the design sensitivity can be calculated efficiently during the evaluation of the probability of failure. Using a mathematical example, the accuracy and efficiency of the developed design sensitivity method are verified. The RBDO result for mathematical and physical problems indicates that the developed method provides accurate design sensitivity in the optimization process.

scholarly journals Research on Intelligent Compaction Technology of Subgrade Based on Regression Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Ziyi Hou ◽  
Xiao Dang ◽  
Yezhen Yuan ◽  
Bo Tian ◽  
Sili Li
Keyword(s):  
Resilient Modulus ◽  
Single Point ◽  
Mean Value ◽  
Test Results ◽  
Intelligent Compaction ◽  
One Dimensional ◽  
Remote Monitoring System ◽  
The Mean ◽  
The One ◽  
Compaction Degree

A remote monitoring system with the intelligent compaction index CMV as the core is designed and developed to address the shortcomings of traditional subgrade compaction quality evaluation methods. Based on the actual project, the correlation between the CMV and conventional compaction indexes of compaction degree K and dynamic resilient modulus E is investigated by applying the one-dimensional linear regression equation for three types of subgrade fillers, clayey gravel, pulverized gravel, and soil-rock mixed fill, and the scheme of fitting CMV to the mean value of conventional indexes is adopted, which is compared with the scheme of fitting CMV to the single point of conventional indexes in the existing specification. The test results show that the correlation between the CMV and conventional indexes of clayey gravel and pulverized gravel is much stronger than that of soil-rock mixed subgrades, and the correlation coefficient can be significantly improved by fitting CMV to the mean of conventional indexes compared with single-point fitting, which can be considered as a new method for intelligent rolling correlation verification.

scholarly journals Epidemiological Comparison between Microsurgery and Embolization of Aneurysms in Brazil from 2010 to 2015

2018 ◽  
Vol 27 (2) ◽  
pp. 168-174
Author(s):  
Matheus De Andrade Bannach ◽  
Mariana Lima Caetano ◽  
Caio Átila Saloio ◽  
José Édison Da Silva Cavalcante ◽  
Helioenai De Sousa Alencar
Keyword(s):  
Health Information System ◽  
Mean Value ◽  
Morbidity And Mortality ◽  
Endovascular Coiling ◽  
P Value ◽  
International Literature ◽  
Surgical Clipping ◽  
The Mean ◽  
Using Data ◽  
The Cost

Introduction: Intracerebral Aneurysms are important causes of morbidity and mortality, with mortality rate of up to 50%. Endovascular coiling was introduced as an alternative to surgical clipping, and has shown better results with a reduction in morbidity and mortality risk of 6-9%. Objective: To characterize the two types of treatment for intracerebral aneurysms within Brazilian scenario, and to compare the results with the international literature. Methods: An analytic observational study using data from the SIH / DATASUS (National Health Information System) in the period of 2010-2015. Results: The total number of hospitalizations decreased, with a 38.3% decrease in clipping and 18.4% in embolizations. The mean value of embolization was significantly higher, however, presenting a downward trend (R$ 22,011.37 in 2010 to R$ 15,607.18 in 2015), while the value of microsurgery increased (R$ 7,022.31 to R$ 8,645.28, respectively). Microsurgery was a risk factor for death (p-value <0.01). Conclusion: It has been shown that the international trend of transition from clipping to embolization did not occur in Brazil. The cost of embolization is much higher. For the authors, the death outcome contrasts with literature due to confounding factors that act within limitations of the study.

Effect of Incorporating Zirconia Powder into a Primer on the Resin Bond Strength to Zirconia Ceramic

2020 ◽  
Vol 20 (9) ◽  
pp. 5575-5578
Author(s):  
Eunkyung Lee ◽  
Yangho Lee ◽  
Young Kyung Kim ◽  
Chan Ho Park ◽  
Tae-Yub Kwon
Keyword(s):  
Bond Strength ◽  
Resin Composite ◽  
Mean Value ◽  
Zirconia Ceramic ◽  
Test Results ◽  
Zirconia Powder ◽  
Scanning Calorimetry ◽  
The Mean ◽  
Ftir Spectrophotometry

The adhesion property of zirconia powder-incorporated primers was investigated in vitro with the aim of enhancing the resin bond strength to zirconia ceramic. A commercial zirconia primer was modified through the addition of 0 (control), 5, 10, 25, and 50 wt% of a zirconia powder (codes: ZP0, ZP5, ZP10, ZP25, and ZP50, respectively). Prior to primer modification, the powder was characterized via differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) spectrophotometry. The surfaces of dental zirconia ceramic discs were air-abraded and treated with one of the five primers. One resin composite cylinder (diameter: 2.38 mm) was bonded on one specimen surface (n = 12/group). The bonded specimens were all stored for 24 h in distilled water at 37 °C and subjected to 5000 thermal cycles prior to shear bond strength (SBS) testing. The DSC and FTIR analyses confirmed that the zirconia powder contained an organic binder. The SBS test results showed that the groups could be arranged as follows, ZP25 > ZP10 > ZP5 > ZP0, i.e., in descending order of the mean value. The lowest SBS value was obtained for the ZP50 group. The results suggest that the incorporation of a zirconia powder into a primer represents a promising modification method for improving the resin bond strength to zirconia ceramic.

Sampling of Insecticides from Pressurized Cans: Collaborative Study

1979 ◽  
Vol 62 (3) ◽  
pp. 494-498
Author(s):  
Yoshihiko Kawano
Keyword(s):  
Confidence Level ◽  
Indirect Method ◽  
Sampling Method ◽  
Collaborative Study ◽  
Mean Value ◽  
Volumetric Flask ◽  
Assembly Method ◽  
Direct Sampling ◽  
Significant Difference ◽  
The Mean

Abstract Seven laboratories collaboratively studied 3 methods for sampling water-based insecticides in pressurized cans. Method 1 was a direct sampling method where the sample was collected continuously from an aerosol outlet into the solvent, using a U-shaped sampling assembly. Method 2 was an indirect method, in which the sample was collected in the solvent from an open can after the propellent was discharged under frozen conditions. Method 3 was an extension of Method 1, where ≥3 samples were collected continuously from an aerosol outlet into the solvent through a U-shaped sampling assembly. The solvent, which contained the active ingredient, was concentrated and transferred to a suitable volumetric flask for gasliquid chromatographic (GLC) analysis. The means of the analytical results for Methods 1 and 3 did not show a significant difference at the 95% confidence level. However, a significant difference was found at the 95% confidence level for the mean value for Method 2 compared with the means for Methods 1 and 3. Methods 1 and 3 have been adopted as official first action for sampling pressurized cans containing aerosols.

On Pricing Unconventional Prepaid Forward Contracts: Evidence from en primeur Fine Wine

2019 ◽  
Vol 14 (4) ◽  
pp. 400-408
Author(s):  
Marcin Czupryna ◽  
Michał Jakubczyk ◽  
Paweł Oleksy
Keyword(s):  
Conceptual Framework ◽  
Bayesian Modeling ◽  
Price Dispersion ◽  
Mean Value ◽  
Forward Contracts ◽  
Forward Contract ◽  
The Mean ◽  
Cost Of Carry ◽  
The Cost ◽  
Jel Classifications

AbstractAn en primeur agreement is an unconventional forward contract. In this article, we provide a new conceptual framework for analyzing the properties of en primeur prices based on the cost of carry approach. The results, based upon Bayesian modeling, indicate that the cost of carry increases up to 0.9598 when en primeur and bottled wines are traded in parallel. Moreover, our findings confirm that price dispersion around the mean value is greater for en primeur wines (22.42%) than for standard bottled wines (8.2%) traded after the sale of en primeur wines has ended. (JEL Classifications: G12, G15, L66, Q02)

scholarly journals The Effectiveness of Patient Safety Cultural Training with Mirror Method and Case Study on Nurse Understanding About Application of Patient Safety at Hospital Pekanbaru

2019 ◽  
Vol 1 (1) ◽  
pp. 11-17
Author(s):  
Awaliyah Ulfah Ayudytha Ezdha ◽  
Silvia Nora Anggreini ◽  
Dwi Elka Fitri
Keyword(s):  
Patient Safety ◽  
Standard Deviation ◽  
Mean Value ◽  
P Value ◽  
Test Results ◽  
Cultural Training ◽  
Lecture Method ◽  
The Mean

Quality development in hospitals has led to efforts to improve quality oriented towards patient safety. The purpose of this study was to compare what methods were most effective between lectures and case studies to improve nurses' understanding of the application of patient safety. The design of the research used is a mix method that is qualitative and quantitative. This research was carried out at Hospital in Pekanbaru with a sample of the study were all nurses who served at the hospital as many as 60 people. The results obtained from the study showed that the mean value of nurses 'understanding of patient safety habit after the lecture method training was 67.47 with a standard deviation of 8.320 while the mean value of nurses' understanding of the HABIT of patient safety after training in the case study method was 73.97 with a standard deviation of 6.835. The independent t test results obtained p value = 0.002. The results of this study are expected in addition to improving the understanding of nurses as well as the hospital can apply the most appropriate method so that the goals of the patient's safety goals are the quality of service can be achieved.

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