scholarly journals Evaluation of impact limiter performance during end-on and slapdown drop tests of a one-third scale model storage/transport cask system

1990 ◽  
Author(s):  
H.R. Yoshimura ◽  
D.R. Bronowski ◽  
W.L. Uncapher ◽  
S.W. Attaway ◽  
V.I. Bateman ◽  
...  
Keyword(s):  
Scale Model ◽  
Drop Tests

An Experimental Study on Rigid-Object Water-Entry Impact and Contact Dynamics

2010 ◽  
Author(s):  
Ravi Challa ◽  
V. G. Idichandy ◽  
C. P. Vendhan ◽  
Solomon Yim
Keyword(s):  
Contact Dynamics ◽  
Experimental Results ◽  
Scale Model ◽  
Water Impact ◽  
Major Purpose ◽  
Closed Form Solutions ◽  
Numerical Studies ◽  
Wave Basin ◽  
Drop Tests ◽  
The Impact

The dynamics of a generic rigid water-landing object (WLO) during water impact is presented in this paper. Tests from a range of drop heights were performed in a wave basin using a 1/6th-Froude scale model of a practical prototype using different drop mechanisms to determine the water impact and contact effects. The first experimental case involved dropping the WLO by using a rope and pulley arrangement, while the second case employed an electromagnetic release to drop the object. Hydrodynamic parameters including peak acceleration, touchdown pressure and maximum impact/contact force were measured using the two different drop mechanisms. The WLO was assumed as rigid, so the experimental results could be correlated with von Karman and Wagner closed form solutions and the maximum accelerations predicted are bounded by these classical analytical solutions. The major purpose of this study are to use the experiments to determine trends that occur when the object is dropped from successive heights using different drop mechanisms by varying the entry speed, angle of impact and the weight of the object. The predictions from the experimental results were used for subsequent numerical studies. Results from the drop tests show that the impact acceleration and touchdown pressure increases practically linearly with the increase in the height of the drop and the data provides conditions of drop mechanism that keep impact accelerations under specified limits for the WLO prototype.

Analytical and Numerical Evaluation of the Impact Limiters Design of a Research Reactors Spent Fuel Transportation Package Half Scale Model Under 9 M Drop Tests

2008 ◽  
Author(s):  
Miguel Mattar Neto ◽  
Carlos A. J. Miranda ◽  
Gerson Fainer ◽  
Roge´rio P. Moura˜o
Keyword(s):  
Scale Model ◽  
Spent Fuel ◽  
Energy Agency ◽  
Dual Purpose ◽  
Research Reactors ◽  
Agency Support ◽  
Drop Tests ◽  
Accident Conditions ◽  
Regional Projects ◽  
The Impact

Since 2001, under the IAEA (International Atomic Energy Agency) support, some regional projects have been developed in Latin America to assess storage and transportion options for the research reactors spent fuel in the region. One of the projects tasks is the design and testing of a half scale model of a dual purpose (transportation and storage) package for research reactors spent fuel. Considering one of the hypothetical accident conditions, the 9 m drop test, this paper presents the impact limiters design evaluation of the above mentioned half scale model of the dual purpose package based on the impact limiters materials characterization, on the analytical assessment of the impact limiters sizing (dimensions and expected package acceleration levels) and on numerical simulations of the drop tests using a finite element explicit code. Conclusions and comments are addressed based on the obtained results.

Instantaneous Leakage Evaluation of Metal Cask at Drop Impact

2006 ◽  
Author(s):  
Hirofumi Takeda ◽  
Norio Kageyama ◽  
Masumi Wataru ◽  
Ryoji Sonobe ◽  
Koji Shirai ◽  
...  
Keyword(s):  
Drop Impact ◽  
Full Scale ◽  
Drop Test ◽  
Leak Rate ◽  
Scale Model ◽  
Storage Facility ◽  
Gas Leakage ◽  
Scale Models ◽  
Helium Gas ◽  
Drop Tests

There have been a lot of tests and analyses reported for evaluation of drop tests of metal casks. However, no quantitative measurement has ever been made for any instantaneous leakage through metal gaskets during the drop tests due to loosening of the bolts in the containments and lateral sliding of the lids. In order to determine a source term for radiation exposure dose assessment, it is necessary to obtain fundamental data of instantaneous leakage. In this study, leak tests were performed by using scale models of the lid structure and a full scale cask without impact limiters simulating drop accidents in a storage facility, with aim of measuring and evaluating any instantaneous leakage at drop impact. Prior to drop tests of a full scale metal cask, a series of leakage tests using scale models were carried out to establish the measurement method and to examine a relationship between the amount of the lateral sliding of the lid and the leak rate. It was determined that the leak rate did not depend on the lateral sliding speeds. Drop tests of a full scale metal cask without impact limiters were carried out by simulating drop accidents during handling in a storage facility. The target was designed to simulate a reinforced concrete floor in the facility. The first test was a horizontal drop from a height of 1 m. The second test simulated a rotational impact around an axis of a lower trunnion of the cask from the horizontal status at a height of 1 m. In the horizontal drop test, the amount of helium gas leakage was calculated by integrating the leak rate with time. The total amount of helium gas leakage from the primary and secondary lids was 1.99×10−6Pa · m3. This value is 9.61×10−9% of the initially installed helium gas. The amount of leakage was insignificant. In the rotational drop test, the total amount of leakage from the primary and secondary lids was 1.74×10−5Pa·m3. This value is 8.45×10−8% of the initially installed helium gas. This value was larger than that of the horizontal drop test. Nevertheless, the amount of leakage was also insignificant. The relationship between the maximum sliding displacement of the lid and the leak rate coincided between the tests of a scale model and a full scale metal cask.

Evaluation of Structural Integrity for a Dry Storage System With Spacer Disks in a Scale Model Drop Test

2008 ◽  
Author(s):  
Woo-Seok Choi ◽  
Kyoung-O Nam ◽  
Kyoung-Sik Bang ◽  
Ju-Chan Lee ◽  
Ki-Seog Seo
Keyword(s):  
Structural Integrity ◽  
Storage System ◽  
Test Procedure ◽  
Relative Displacement ◽  
Drop Test ◽  
Scale Model ◽  
Dry Storage ◽  
Drop Tests ◽  
New Type ◽  
Test Result

A new type of dry storage system has been developed in Korea. The dry storage cask under development consists of a cask body, a canister, and an in-canister structure. The in-canister structure is a complicated structure with many baskets and spacer disks. The spacer disks are originally designed to dissipate the heat from the baskets but they also influence the structural behavior. To evaluate a spacer disks’ influence on the overall structure behavior, especially on the characteristics when it is under a drop test, analyses and tests were conducted. Based on the analysis result, the sensor location and type is determined. Test result is utilized to validate the analysis result. After the drop tests, some strain gauges were detached from the original positions since the relative displacement between a basket and a disk removed the cable from the sensor. Thus, careful attention has to be paid when installing the sensors and cabling inside the in-canister structure. By means of these analyses and tests, the availability of the sensor and cabling arrangement is evaluated and a test procedure is established.

Aerodynamics of a Badminton Shuttlecock

2009 ◽  
Author(s):  
S. L. Post ◽  
Jordan McLachlan ◽  
Travis Lonas ◽  
Justin Dancs ◽  
Daniel Knobloch ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Fluid Mechanics ◽  
Drag Coefficient ◽  
High Accuracy ◽  
Scale Model ◽  
Limited Data ◽  
Technical Literature ◽  
Drag Coefficients ◽  
Class Project ◽  
Drop Tests

This paper presents a class project that can be performed in a junior-level fluid mechanics course. Students gain experience in design and conducting experiments, and in reviewing the relevant technical literature. Experiments were conducted to determine the drag coefficient of a badminton shuttlecock. Two types of testing were conducted: wind tunnel tests of a full-scale model, and drop tests using a high-accuracy radar gun. The drag coefficients calculated from these measurements were then compared to the limited data available in the literature. The range of drag coefficients measured was from 0.55 to 0.65.

Modeling Within-Person Variance in Reaction Time Data of Older Adults

GeroPsych ◽  
2011 ◽  
Vol 24 (4) ◽  
pp. 169-176 ◽  
Author(s):  
Philippe Rast ◽  
Daniel Zimprich
Keyword(s):  
Reaction Time ◽  
Cognitive Aging ◽  
Reaction Times ◽  
Reaction Time Task ◽  
Reaction Time Data ◽  
Scale Model ◽  
Time Data ◽  
Time Task ◽  
The Mean ◽  
Second Wave

In order to model within-person (WP) variance in a reaction time task, we applied a mixed location scale model using 335 participants from the second wave of the Zurich Longitudinal Study on Cognitive Aging. The age of the respondents and the performance in another reaction time task were used to explain individual differences in the WP variance. To account for larger variances due to slower reaction times, we also used the average of the predicted individual reaction time (RT) as a predictor for the WP variability. Here, the WP variability was a function of the mean. At the same time, older participants were more variable and those with better performance in another RT task were more consistent in their responses.

Using the Rating Scale Model to Examine the Psychometric Properties of the Self-Efficacy Scale for Driver Competence

2011 ◽  
Vol 27 (3) ◽  
pp. 164-170 ◽  
Author(s):  
Anna Sundström
Keyword(s):  
Psychometric Properties ◽  
Self Efficacy ◽  
Rating Scale ◽  
Measurement Precision ◽  
The Self ◽  
Test Theory ◽  
Self Report ◽  
Scale Model ◽  
Validity And Reliability ◽  
Two Samples

This study evaluated the psychometric properties of a self-report scale for assessing perceived driver competence, labeled the Self-Efficacy Scale for Driver Competence (SSDC), using item response theory analyses. Two samples of Swedish driving-license examinees (n = 795; n = 714) completed two versions of the SSDC that were parallel in content. Prior work, using classical test theory analyses, has provided support for the validity and reliability of scores from the SSDC. This study investigated the measurement precision, item hierarchy, and differential functioning for males and females of the items in the SSDC as well as how the rating scale functions. The results confirmed the previous findings; that the SSDC demonstrates sound psychometric properties. In addition, the findings showed that measurement precision could be increased by adding items that tap higher self-efficacy levels. Moreover, the rating scale can be improved by reducing the number of categories or by providing each category with a label.

An IRT Investigation of the Validity of Non-Patient Analogue Research Using the Beck Depression Inventory

1995 ◽  
Vol 11 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Sean M. Hammond
Keyword(s):  
Differential Item Functioning ◽  
Beck Depression Inventory ◽  
Rating Scale ◽  
Latent Trait ◽  
Scale Model ◽  
Item Functioning ◽  
Two Samples ◽  
Patient Groups ◽  
Analogue Research ◽  
Rating Scale Model

This paper presents an IRT analysis of the Beck Depression Inventory which was carried out to assess the assumption of an underlying latent trait common to non-clinical and patient samples. A one parameter rating scale model was fitted to data drawn from a patient and non-patient sample. Findings suggest that while the BDI fits the model reasonably well for the two samples separately there is sufficient differential item functioning to raise serious duobts of the viability of using it analogously with patient and non-patient groups.

Modeling Intraindividual Variability in Three-Level Multilevel Models

Methodology ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 95-108 ◽  
Author(s):  
Steffen Nestler ◽  
Katharina Geukes ◽  
Mitja D. Back
Keyword(s):  
Multilevel Model ◽  
Multilevel Models ◽  
Mixed Effects ◽  
Repeated Measurements ◽  
Scale Model ◽  
Suggested Approach ◽  
Psychological Study ◽  
Level Data ◽  
Ecological Momentary ◽  
Momentary Assessment

Abstract. The mixed-effects location scale model is an extension of a multilevel model for longitudinal data. It allows covariates to affect both the within-subject variance and the between-subject variance (i.e., the intercept variance) beyond their influence on the means. Typically, the model is applied to two-level data (e.g., the repeated measurements of persons), although researchers are often faced with three-level data (e.g., the repeated measurements of persons within specific situations). Here, we describe an extension of the two-level mixed-effects location scale model to such three-level data. Furthermore, we show how the suggested model can be estimated with Bayesian software, and we present the results of a small simulation study that was conducted to investigate the statistical properties of the suggested approach. Finally, we illustrate the approach by presenting an example from a psychological study that employed ecological momentary assessment.

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