Evaluation of Cumulative Damage From Drop to Puncture Conditions

2012 ◽  
Author(s):  
Woo-Seok Choi ◽  
Sanghoon Lee ◽  
Kyoung-Sik Bang ◽  
Ju-Chan Lee ◽  
Ki-Seog Seo
Keyword(s):  
Numerical Simulations ◽  
Initial Conditions ◽  
Water Immersion ◽  
Cumulative Damage ◽  
Single Event ◽  
Physical Test ◽  
Sequential Event ◽  
Physical Tests ◽  
Hypothetical Accident ◽  
Accident Conditions

During safety assessments of transport packages, cumulative damages are naturally accumulated for assessments performed using physical tests specimens. However, the cumulative damages are not as easily accounted when assessments are by numerical simulations. While analysts are comfortable with simulating packages for single events, it is not yet common practice to incorporate the effect handed over from a former event to the next, in a series of sequential load events. Thus, many numerical simulations in SAR (Safety Analysis Report) represent just a single event in the series of sequential event comprising the required accident condition. These single event numerical simulations are then based on initial conditions different from the analogous physical test specimen, which could contribute to a growing disparity in results between assessments by physically testing compared to numerical simulation. The reason why analyses do not consider the cumulative damage is difficulties in delivering the final result of the previous analysis to the current analysis. The hypothetical accident conditions described in the IAEA regulations include drop, puncture, fire, and water immersion conditions, which should be sequentially simulated. There can be cumulative damage between two accident conditions, such as drop and puncture, puncture and fire, and so forth. In this study, as the first step to consider cumulative damage, an analysis technology to perform a puncture analysis incorporating the final response field from a prior drop analysis is proposed. The necessity and validity of the proposed analysis technology are evaluated by a comparison with the results obtained by performing each analysis independently.

Evaluation of Cumulative Damage in a Series of Sequential Load Events

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Woo-Seok Choi ◽  
Ki-Seog Seo
Keyword(s):  
Numerical Simulations ◽  
Initial Conditions ◽  
Water Immersion ◽  
Cumulative Damage ◽  
Single Event ◽  
Energy Agency ◽  
Physical Test ◽  
Physical Tests ◽  
Hypothetical Accident ◽  
Accident Conditions

During the safety assessments of transport packages, cumulative damages are naturally accumulated for assessments performed using physical tests specimens. However, such cumulative damages are not as easily accounted for when assessments are made through numerical simulations. While analysts are comfortable with simulating packages for single events, it is not yet common practice to incorporate the effect handed over from a former event to the next, in a series of sequential load events. Thus, many numerical simulations in a safety analysis report (SAR) represent just a single event in a series of sequential events comprising the required accident conditions. These single event numerical simulations are then based on the initial conditions that differ from the analogous physical test specimen, which could contribute to a growing disparity in the results between assessments through physical testing compared to a numerical simulation. The reason why analyses do not consider the cumulative damage is difficulties in delivering the final results of the previous analysis to the current analysis. The hypothetical accident conditions described in the International Atomic Energy Agency (IAEA) regulations include drop, puncture, fire, and water immersion conditions, which should be sequentially simulated. There can be cumulative damage between two accident conditions, such as drop and puncture, puncture and fire, and so forth. In this study, as the first step to consider cumulative damage, an analysis technology to perform a puncture analysis incorporating the final response field from a prior drop analysis is proposed. The necessity and validity of the proposed analysis technology are evaluated through a comparison with the results obtained by performing each analysis independently.

Digital Radiography of General Purpose Fissile Packages

2005 ◽  
Author(s):  
Boyd Howard ◽  
Larry Gelder
Keyword(s):  
Digital Radiography ◽  
Effective Means ◽  
General Purpose ◽  
Test Sequence ◽  
Large Area ◽  
Area Detector ◽  
Physical Tests ◽  
Hypothetical Accident ◽  
Large Area Detector ◽  
Accident Conditions

Digital radiography provides an effective means of non-destructively examining the effects of physical tests on the interior structure of a Radioactive Materials Packaging. As such it enables evaluation of the effects of the Hypothetical Accident Conditions Sequential Test on a package, following each step in the test sequence. An introduction to digital radiography is given and application of CCD-based, lens-coupled, large area-detector, digital radiography in the HAC testing of the prototype General Purpose Fissile Packaging is described. The radiographs enable correlation of damage with particular steps in the test sequence.

Behavior of FRP Sandwich Panels under Synergistic Effects of Low Temperature and Cyclic Loading I: Experiment and Numerical Simulation Method

2011 ◽  
Vol 378-379 ◽  
pp. 102-107 ◽  
Author(s):  
Bai Song Du ◽  
Zhong Guo Ma ◽  
Ling Luo
Keyword(s):  
Numerical Simulations ◽  
Mechanical Performance ◽  
Initial Conditions ◽  
Synergistic Effects ◽  
Mesh Size ◽  
Simulation Method ◽  
Experimental Results ◽  
Incremental Method ◽  
Different Temperatures ◽  
Physical Tests

The paper is concerned with using experiments and numerical simulations to study the mechanical performance of a Honeycomb Fiber-Reinforced Polymer (HFRP) sandwich panel at different temperatures, especially at low temperatures coupled with cyclic loadings. All physical tests were performed in a temperature controlled room and used a three-point bending setup where the applied load gradually increased from zero to 36kN. Experimental results show that the stiffness of the panel becomes softer at some lower temperatures. In order to eliminate the influence of the initial conditions, an incremental method was introduced to process the experimental results. This method treated all displacements and strains as zero when applying a load of 4.5kN. Furthermore, the change in stiffness of the panel was obtained through the use of a special equivalent stiffness which involved measuring the change of the stiffness of the panel. After comparing different methods, the composite shell method was used to build finite element models for numerical simulations in ABAQUS. Reduction of moduli and Random Mesh Size Method (RMSM) were employed to simulate microcracking between fibers and matrix and debonding between the core and face sheets, respectively.

scholarly journals The Impact of Initial Conditions in N-Body Simulations of Debris Discs

2015 ◽  
Vol 32 ◽  
Author(s):  
E. Thilliez ◽  
S. T. Maddison
Keyword(s):  
Numerical Simulations ◽  
Initial Conditions ◽  
Parent Body ◽  
Dust Trapping ◽  
Physical Context ◽  
Disc Width ◽  
Wide Range ◽  
Belt Width ◽  
New Generation ◽  
The Impact

AbstractNumerical simulations are a crucial tool to understand the relationship between debris discs and planetary companions. As debris disc observations are now reaching unprecedented levels of precision over a wide range of wavelengths, an appropriate level of accuracy and consistency is required in numerical simulations to confidently interpret this new generation of observations. However, simulations throughout the literature have been conducted with various initial conditions often with little or no justification. In this paper, we aim to study the dependence on the initial conditions of N-body simulations modelling the interaction between a massive and eccentric planet on an exterior debris disc. To achieve this, we first classify three broad approaches used in the literature and provide some physical context for when each category should be used. We then run a series of N-body simulations, that include radiation forces acting on small grains, with varying initial conditions across the three categories. We test the influence of the initial parent body belt width, eccentricity, and alignment with the planet on the resulting debris disc structure and compare the final peak emission location, disc width and offset of synthetic disc images produced with a radiative transfer code. We also track the evolution of the forced eccentricity of the dust grains induced by the planet, as well as resonance dust trapping. We find that an initially broad parent body belt always results in a broader debris disc than an initially narrow parent body belt. While simulations with a parent body belt with low initial eccentricity (e ~ 0) and high initial eccentricity (0 < e < 0.3) resulted in similar broad discs, we find that purely secular forced initial conditions, where the initial disc eccentricity is set to the forced value and the disc is aligned with the planet, always result in a narrower disc. We conclude that broad debris discs can be modelled by using either a dynamically cold or dynamically warm parent belt, while in contrast eccentric narrow debris rings are reproduced using a secularly forced parent body belt.

Physical function tests predict incident falls: A prospective study of 2969 men in the Swedish Osteoporotic Fractures in Men study

2018 ◽  
Vol 48 (4) ◽  
pp. 436-441 ◽  
Author(s):  
Marcus E. Cöster ◽  
Magnus Karlsson ◽  
Claes Ohlsson ◽  
Dan Mellström ◽  
Mattias Lorentzon ◽  
...  
Keyword(s):  
Grip Strength ◽  
Osteoporotic Fractures ◽  
The Elderly ◽  
Population Based ◽  
Hand Grip Strength ◽  
Test Time ◽  
Physical Test ◽  
Walking Test ◽  
Hand Grip ◽  
Physical Tests

Aims: Falls are common in the elderly population, and fall-related injuries are a major health issue. We investigated the ability of simple physical tests to predict incident falls. Methods: The Swedish Osteoporotic Fractures in Men (MrOS) study includes 3014 population-based men aged 69–81 years at the start of the study. These men performed five different physical tests at baseline: right-hand grip strength, left-hand grip strength, timed stand test, 6 m walking test (time and steps) and narrow walking test. During the first study year, we asked participants to fill out questionnaires regarding falls 4, 8 and 12 months after baseline. A total of 2969 men completed at least one questionnaire and were included in this study. We used generalised estimating equations and logarithmic regression models to estimate odds ratios for fallers and recurrent fallers (more than one fall during the one-year examination period) in each quartile of men for each physical test. Results: The proportions of fallers and recurrent fallers were higher in the lowest quartile of the physical tests than in the other three quartiles combined for all physical tests. A reduction of one standard deviation in respective physical test resulted in a 13–21% higher risk of becoming a faller and a 13–31% higher risk of becoming a recurrent faller. Conclusions: Low results on simple physical tests is a risk factor for incident falls in elderly Swedish men and may facilitate identification of high-risk individuals suitable for fall-intervention programs.

3D numerical simulations of single-event transient effects in SOI FinFETs

2018 ◽  
Vol 17 (4) ◽  
pp. 1608-1614 ◽  
Author(s):  
Zhenyu Wu ◽  
Benneng Zhu ◽  
Tengyue Yi ◽  
Chao Li ◽  
Yi Liu ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Single Event ◽  
Transient Effects ◽  
Single Event Transient

Dynamics of Dual-Cell Series Miura-Ori Structures With Different Types of Inter-Cell Connections

2021 ◽  
Author(s):  
Hai Zhou ◽  
Haiping Wu ◽  
Jian Xu ◽  
Hongbin Fang
Keyword(s):  
Steady State ◽  
Numerical Simulations ◽  
Theoretical Basis ◽  
Initial Conditions ◽  
Cell Structure ◽  
Dynamic Responses ◽  
Complex Environment ◽  
Current State ◽  
Different Types ◽  
Cell Series

Abstract Origami-inspired structures and materials have shown remarkable properties and performances originating from the intricate geometries of folding. Origami folding could be a dynamic process and origami structures could possess rich dynamic characteristics under external excitations. However, the current state of dynamics of origami has mostly focused on the dynamics of a single cell. This research has performed numerical simulations on multi-stable dual-cell series Miura-Ori structures with different types of inter-cell connections based on a dynamic model that does not neglect in-plane mass. We introduce a concept of equivalent constraint stiffness k* to distinguish different types of inter-cell connections. Results of numerical simulations reveal the multi-stable dual-cell structure will exhibit a variety of complex nonlinear dynamic responses with the increasing of connection stiffness because of the deeper energy well it has. The connection stiffness has a strong effect on the steady-state dynamic responses under different excitation amplitudes and a variety of initial conditions. This effect makes us able to adjust the dynamic behaviors of dual-cell series Miura-Ori structure to our needs in a complex environment. Furthermore, the results of this research could provide us a theoretical basis for the dynamics of origami folding and serve as guidelines for designing dynamic applications of origami metastructures and metamaterials.

Design and Analysis of Shipping Container for Big Rock Decommissioned Reactor Vessel

2014 ◽  
Author(s):  
Bruce (Bart) Slimp ◽  
Mick Papp ◽  
Phuong H. Hoang
Keyword(s):  
Structural Analysis ◽  
Base Material ◽  
Reactor Vessel ◽  
Radioactive Material ◽  
Type B ◽  
Shipping Container ◽  
Analysis Methodology ◽  
Maximum Wall Thickness ◽  
Hypothetical Accident ◽  
Accident Conditions

A major milestone in 2003 on the Big Rock Point (BRP) decommissioning project involved shipping the Reactor Vessel (RV) in a steel cask for burial. The Reactor Vessel Transport System (RVTS) cask was a sealed integral container, which provided necessary radiological shielding and containment of radioactive waste for shipping and disposal. The RVTS, using the provisions of the ASME BPVC Section III, Subsection NB, was designed as a Type B package in accordance with the requirements of 10 CFR Part 71. This included meeting Normal Condition of Transport (NCT) and the Hypothetical Accident Conditions (HAC) loading per 10 CFR 71, Regulatory Guide 7.6, “Design Criteria for the Structural Analysis of Shipping Cask Containment Vessels,” Regulatory Guide 7.8, “Load Combinations for the Structural Analysis of Shipping Casks for Radioactive Material” and Regulatory Guide 7.11, “Fracture Toughness Criteria of Base Material for Ferritic Steel Shipping Cask Containment Vessels with a Maximum Wall Thickness of 4 Inches.” The RVTS was designed to withstand accelerations and shocks postulated during highway and rail transit using guidelines from the Association of American Railroads (AAR) and ANSI N14.2. The design analysis methodology, fabrication process and transportation planning for the Big Rock RVTS Cask are presented in this paper.

scholarly journals Supervised and home-based physical exercise in patients newly diagnosed with multiple myeloma—a randomized controlled feasibility study

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Rikke Faebo Larsen ◽  
Mary Jarden ◽  
Lisbeth Rosenbek Minet ◽  
Ulf Christian Frølund ◽  
Niels Abildgaard
Keyword(s):  
Multiple Myeloma ◽  
Bone Disease ◽  
Exercise Intervention ◽  
Newly Diagnosed ◽  
Test Procedures ◽  
Physical Test ◽  
Randomized Controlled ◽  
Supervised Exercise ◽  
Home Based ◽  
Physical Tests

Abstract Background The study evaluated the feasibility and safety of the exercise intervention and physical test procedures of our ongoing randomized controlled trial, examining the effect of physical exercise in newly diagnosed patients with multiple myeloma. Methods Patients are randomized 1:1 to a control group (usual care) or an intervention group (usual care and exercise) by block randomization with stratification of planned treatment, WHO performance status, and study site. The exercise intervention consists of eight supervised exercise sessions combined with home-based exercise over a 10-week period. Bone disease is systematically evaluated to determine limitations regarding physical testing and/or exercise. Feasibility outcome measures were study eligibility, acceptance, and attrition, and furthermore attendance, adherence, tolerability, and safety to the exercise intervention. Additionally, test completion, pain, and adverse events during the physical test procedures were evaluated. Outcome assessors were blinded to allocation. Results Of 49 patients screened, 30 were included. The median age was 69 years, range 38–90, 77% were males, and 67% had bone disease. Study eligibility was 82%, acceptance 75%, and attrition 20%. Attendance at supervised exercise sessions was 92%, and adherence to supervised exercise sessions and home-based exercise sessions was 99% and 89%, respectively. No serious adverse events attributed to exercise or physical tests were reported. All patients completed the physical tests, except for two patients, where physical test procedures were modified due to bone disease. Discussion The exercise intervention and physical test procedures were feasible and safe in patients with multiple myeloma, even in older patients with multiple myeloma and in patients with myeloma bone disease. Trial registration ClinicalTrials.gov. ID NCT02439112. Registered on May 7, 2015.

Study of Heat Mass and Mass Transfers in a Spray for Containment Application: Analysis of the Influence of the Spray Mass Flow Rate

2008 ◽  
Author(s):  
Pascal Lemaitre ◽  
Emmanuel Porcheron
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Nuclear Power ◽  
Initial Conditions ◽  
Hydraulic Behaviour ◽  
Application Analysis ◽  
Mass Flow Rates ◽  
Hypothetical Accident ◽  
Mass Transfers

During the course of a hypothetical accident in a nuclear power plant, spray might be activated in order to reduce static pressure in the containment. To have a better understanding of the heat and mass transfers between a spray and the surrounding confined gas, the IRSN has developed the TOSQAN experiment. This article is devoted to analyse the influence of the injected spray mass flow rate on the thermal-hydraulic of spray tests. In order to perform this analysis, two other tests are performed with exactly the same boundary and initial conditions, except the spray mass flow rate that ranges from 10 to 50 g.s−1. First, the scenario of these three tests and the associated results used for this analysis are presented. Then, we focus our analysis on the inter-comparison of the thermal-hydraulic behaviour induced by spray mass flow rates variations. This inter-comparison is divided into two parts: a global and a local one.

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