Reliability Study on a New Integrity Pressure Relief Device in Nonrefillable Steel Gas Cylinder

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Weiya Jin ◽  
Yuebing Li ◽  
Mingjue Zhou ◽  
Zengliang Gao
Keyword(s):  
Material Properties ◽  
Groove Depth ◽  
Burst Pressure ◽  
Reliability Study ◽  
Pressure Relief ◽  
Gas Cylinder ◽  
Reliability Method ◽  
Rupture Disk ◽  
Safety And Reliability ◽  
Very High

A new integrity pressure relief device in a nonrefillable steel gas cylinder is proposed and tested. Instead of a rupture disk welded on the opening of the head, the new integrity pressure relief device is machined by stamping a circular groove on the vessel head, which not only avoids an additional penetration on the head but also reduces the manufacture cost. To ensure the safety and reliability of the device, its performance is evaluated using a reliability method based on material properties and burst pressure. The effect of stamping pressure on the groove depth is investigated, and then, the material properties taken from different locations are tested. Tensile properties taken along the circumferential direction of the cylinder are suggested to be used to predict burst pressure of the new integrity pressure relief device. The tolerance of the burst pressure in a percentage is analyzed, and a probabilistic model is built. The reliability analysis shows that the batch of cylinders with the integrity pressure relief device has a very high qualified probability.

Covid-19 Literacy Scale: Turkish Validity and Reliability Study

2021 ◽  
pp. 105477382110598
Author(s):  
Ganime Can Gür ◽  
Yasemin Altinbaş
Keyword(s):  
Construct Validity ◽  
Factor Structure ◽  
Internal Consistency ◽  
Content Validity ◽  
Model Data ◽  
Validity And Reliability ◽  
Turkish Version ◽  
Reliability Study ◽  
Reliability Method ◽  
Test Retest Reliability

The current study was planned to test the validity and reliability of the Turkish version of the COVID-19 Literacy Scale. The sample of the study was taken from 473 individuals. In this study, language validity, content validity and construct validity were examined to determine the validity of the scale. Its reliability was evaluated by internal consistency, split-half reliability, and test-retest reliability method. It was defined that the scale has a two-factor structure as a result of EFA and its factor loadings are in the appropriate range (0.852–0.324). According to the CFA result, it was determined that the model-data fit was at a good level. The Cronbach values for the whole scale and subscales were .92, .90, and .87, respectively. It was observed that the test-retest value was .95. It was concluded that the Turkish form of the COVID-19 Literacy Scale is a reliable and valid tool.

Hygrothermal Buckling Response of Laminated Composite Plates with Random Material Properties: Micro-Mechanical Model

2011 ◽  
Vol 110-116 ◽  
pp. 113-119 ◽  
Author(s):  
Rajesh Kumar ◽  
Dharamveer Singh
Keyword(s):  
Material Properties ◽  
Plate Theory ◽  
Perturbation Technique ◽  
Micromechanical Model ◽  
Laminated Composite ◽  
Composite Plates ◽  
Second Order Statistics ◽  
Operational Life ◽  
Safety And Reliability ◽  
Random Material Properties

The aim of this paper is to find out the randomness in the material properties on the buckling of laminated composite plate needed for the economy, safety and reliability of the structures and components in their operational life especially for sensitive Aerospace Engineering applications in hygrothermal environments. Micromechanical model has been taken for the analysis .The used methodology is a C0 finite element method based on higher-order shear deformation plate theory for deriving the standard eigenvalue problem. A Taylor series based mean-centered first order perturbation technique is used to find out the second order statistics of the hygrothermal buckling loads under different sets of environmental conditions..The numerical results for deterministic parameters are compared and validated with available literature and random parameters with independent Monte Carlo Simulation. The result shows that the plate is significantly affected by the hygrothermal buckling load.

Analysis of Strength and Residual Stresses in Filament Reinforced Aluminum Cylinders

1975 ◽  
Vol 97 (3) ◽  
pp. 192-198
Author(s):  
F. A. Simonen ◽  
N. C. Henderson ◽  
R. D. Winegardner ◽  
K. Specht
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Relative Increase ◽  
Burst Pressure ◽  
Experimental Measurements ◽  
Gas Cylinder ◽  
Proof Testing ◽  
Gas Cylinders

This paper describes a study of aluminum gas cylinders used in underwater manned vehicles. A determination was made of the relative increase in one cycle burst pressure and fatigue life of an existing aluminum gas cylinder when the sidewall was reinforced with fiberglass overwrap and prestressed by over pressurization. Detailed finite-element stress analyses were conducted to determine the operating stresses and also the residual stresses at the end cap-to-cylinder transition section which were a result of plastic deformation during proof testing. Calculated residual stresses were found to be consistent with experimental measurements. It was determined that the filament reinforcement both increased the vessel burst pressure and increased the vessel fatigue life through favorable prestress effects. Results of vessel fatigue and burst tests are presented and are compared with the predicted performance characteristics.

scholarly journals Recent Progress of Diamond Device toward Power Application

2009 ◽  
Vol 615-617 ◽  
pp. 999-1002 ◽  
Author(s):  
Shinichi Shikata ◽  
Kazuhiro Ikeda ◽  
Ramanujam Kumaresan ◽  
Hitoshi Umezawa ◽  
Natsuo Tatsumi
Keyword(s):  
Epitaxial Growth ◽  
Material Properties ◽  
Recent Progress ◽  
High Current Density ◽  
Short Review ◽  
Growth Conditions ◽  
High Current ◽  
Step Flow ◽  
Power Application ◽  
Very High

Diamond is nominated as a material candidate for future high power device due to its superior material properties and resulting very high FOM. In this paper, our recent progresses and the expected possibilities of diamond for power electronics applications are introduced as short review. Firstly for the epitaxial growth, by adopting step-flow epitaxial growth by off- angle substrate with optimized growth conditions, we have succeeded in reducing these killer defects almost six orders from 106cm-2 to almost 100cm-2 levels. For the substrate, our recently developed technology to fabricate diamond plates from bulk, 12x13mm2 size are available to use, that can avoid fabrication difficulties with small size substrate. Secondly for the device, primitive studies showed possibly for the advantage of diamond such as low reverse leakage current, high temperature and high current density operation.

Influence of the Brittle Behavior of Work Materials on Microgrooving

2016 ◽  
Vol 703 ◽  
pp. 17-21 ◽  
Author(s):  
Satoshi Sakamoto ◽  
Masaya Gemma ◽  
Keitoku Hayashi ◽  
Yasuo Kondo ◽  
Kenji Yamaguchi ◽  
...  
Keyword(s):  
Tool Wear ◽  
Material Properties ◽  
Relative Velocity ◽  
Processing Time ◽  
Groove Depth ◽  
Processing Conditions ◽  
Processing Efficiency ◽  
Brittle Behavior ◽  
Work Material ◽  
Hard And Brittle Materials

An electroplated diamond wire tool is frequently used for the machining of hard and brittle materials such as silicon ingots, magnetic materials, ceramics, and sapphires. This study aims to examine the influence of brittle behavior of work materials on machinability (including tool wear); therefore, we conduct dynamic ultramicro hardness measurements and microgrooving experiments for three types of ceramics. The results indicate that the groove depth of a work material tends to increase with the processing time. Moreover, material properties of a work material, such as hardness and toughness, have a significant impact on the fluctuations in its groove depth. However, kerf width of a work material does not depend on the processing conditions and material properties. In addition, a faster relative velocity improves processing efficiency but also increases tool wear.

scholarly journals Safety of Construction Components in a Very High Number of Load Cycles

2020 ◽  
Vol 2 (1) ◽  
pp. 199-206
Author(s):  
František Nový ◽  
Juraj Belan ◽  
Otakar Bokůvka
Keyword(s):  
Fatigue Resistance ◽  
High Frequency ◽  
Asymmetry Parameter ◽  
High Strength ◽  
Cyclic Stress ◽  
Average Value ◽  
Safety And Reliability ◽  
Important Position ◽  
Very High

AbstractProgressive, high-strength materials have an important position in the transport industry. In this industry, components are subject to high safety and reliability requirements because they often operate under long-term cyclic stress regimes. The paper presents results of fatigue resistance of high-strength materials such DOMEX 700MC, HARDOX 400, HARDOX 450, and INCONEL 718 (UTS from 850 to 1560 MPa) measured at high-frequency cyclic loading (f = 20 kHz, T = 20 ± 5 ° C, push-pull loading, cycle asymmetry parameter of R = -1) in the area from N = 2x106 to N = 2x108 cycles. Fatigue resistance showed a continuous decrease about average value Sa 2x108/Sa 2x106 = 19.1%.

scholarly journals Effect of Punch Surface Grooves on Microformability of AA6063 Backward Microextrusion

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1299
Author(s):  
Tatsuya Funazuka ◽  
Kuniaki Dohda ◽  
Tomomi Shiratori ◽  
Ryo Hiramiya ◽  
Ikumu Watanabe
Keyword(s):  
Surface Properties ◽  
Material Properties ◽  
Size Effects ◽  
Groove Depth ◽  
The Other ◽  
Extrusion Force ◽  
Micro Scale ◽  
Backward Extrusion ◽  
Tool Surface ◽  
Frictional Effects

In order to apply conventional forming processes at the micro scale, the size effects caused by material properties and frictional effects must be taken into account. In this research, the effects of tool surface properties such as punch surface grooves on microextrudability, assessed using extrusion force, shape of the extrusion, and Vickers hardness, were investigated using an AA6063 billet. Microscale grooves of 5 to 10 µm were fabricated on the punch surface. The extrusion force increased rapidly as the stroke progressed for all the grooves. Comparing the product geometries showed that, the smaller the groove size, the lower the adhesion and the longer the backward extrusion length. The results of material analysis using EBSD showed that a 5 µm groove depth punch improved the material flowability and uniformly introduced more strain. On the other hand, material flowability was reduced and strain was applied nonuniformly when a mirror-finish tool was used. Therefore, the tribology between the tool and the material was controlled by changing the surface properties of the punch to improve formability.

scholarly journals Forgiveness flexibility scale for secondary education: Validity and reliability studyOrtaöğretim öğrencilerinde affetme esnekliği ölçeği: Geçerlik ve güvenirlik çalışması

2017 ◽  
Vol 14 (1) ◽  
pp. 39 ◽  
Author(s):  
Tuğba Seda Çolak ◽  
Mustafa Koç ◽  
Halime Eker ◽  
Betül Düşünceli
Keyword(s):  
Factor Analysis ◽  
Secondary Education ◽  
Exploratory Factor Analysis ◽  
Reliability And Validity ◽  
Test Reliability ◽  
Validity And Reliability ◽  
Education Students ◽  
Reliability Study ◽  
Reliability Method ◽  
Valid Instrument

The aim of the study is to develop a scale which determines forgiveness flexibility level of secondary education students and to test reliability and validity of the scale. The study was actualized with 651 secondary education students. As result of exploratory factor analysis, which was used to test structure validity of the scale, a structure which explains 45.5% variance of total scale was attained. According to results of exploratory factor analysis, total 14 items collected at three factors. Factors were identified as recognition of forgiveness, internalization of forgiveness and practice of genuine forgiveness. When scale’s reliability study was made by split-half reliability method, correlation found .71 (p<.01). It can be said based on the findings that Forgiveness Flexibility Scale High School Form is a reliable and valid instrument which can be used in the fields of education and psychology. ÖzetAraştırmanın amacı, ortaöğretim öğrencilerinde affetme esnekliğini belirleyen bir ölçek geliştirmek ve ölçeğin geçerlik ve güvenirliğini test etmektir. Araştırma 651 ortaöğretim öğrencisi ile gerçekleştirilmiştir. Ölçeğin yapı geçerliliğini test etmek için kullanılan açımlayıcı faktör analizi sonucunda ölçeğin toplam varyansının %45.5’ini açıklayan bir yapı elde edilmiştir. Açımlayıcı faktör analizi sonuçlarına göre; toplam 14 madde, üç faktörde toplanmaktadır. Faktörler affetmeyi tanıma, affetmeyi içselleştirme ve gerçek affetmeyi uygulama olarak tanımlanmıştır. Ölçeğin güvenirlik çalışması testi ikiye ayırma yöntemi ile gerçekleştirildiğinde .71 (p<.01) korelasyon bulunmuştur. Bu sonuçlara dayanarak Affetme Esnekliği Lise Formu Ölçeğinin eğitim ve psikoloji alanında kullanılabilecek, geçerli ve güvenilir bir ölçme aracı olduğu söylenebilir.

Measurements of Displacements and Deformations and Reliability Analysis of Base Transceiver Station (BTS) Made of Steel

2017 ◽  
Author(s):  
Izabela Skrzypczak ◽  
Grzegorz Oleniacz ◽  
Przemysław Leń ◽  
Monika Mika
Keyword(s):  
Mobile Communications ◽  
Reliability Index ◽  
Design Stage ◽  
Building Structures ◽  
Reliability Method ◽  
Safety And Reliability ◽  
The Stability ◽  
Index Value ◽  
Building Standards ◽  
Steel Trusses

Safety and reliability of BaseTransceiver Station (BTS) in Global System for Mobile Communications (GSM) should be provided not only at the design stage and construction work, but also during the service. The technical conditions and safety of building structures is also dependent on the determination of geometric deviation of the entire structure and its individual components. This should be referred to the recommendations of code limits. The geodetic measurements of displacements and deformations of objects are extremely important to evaluate the stability and security of the structure and its maintenance. Steel trusses or concrete columns must meet the requirements of building standards and instructions as well as the standard requirements for the deviation limits during the construction phase and operational work. The primary and overarching objective of inventory of BTS is to ensure that the safety of the service and the users is fulfilled. The investigation of the reliability of BTS towers by determining the reliability index value using First Order Reliability Method (FORM) recommended in Eurocode 0 will be perfomed. The values of reliability index will be defined for the serviceability limit.

Differential Burst Pressure of Marine Pipelines as an Independent Layer of Protection

2011 ◽  
Author(s):  
Sirous F. Yasseri ◽  
R. B. Mahani
Keyword(s):  
Burst Pressure ◽  
Offshore Pipelines ◽  
First Order ◽  
Reliability Method ◽  
Structural Fuse ◽  
Environmentally Sensitive ◽  
Protection Layer ◽  
Pressure Surge ◽  
Pipeline Design

Offshore pipelines and risers are designed to different codes leading to different reliability targets, and different wall thicknesses. Pipeline design codes also differentiate between areas where people are present and those with no population or less environmentally sensitive. As a result, the offshore section of the pipeline (with “thinner walls”) could be considered to work as a structural fuse during an unforeseen pressure surge; if the pipeline bursts first, then the occupants of platform would be exposed to less risk than if the riser or pipeline in the vicinity of the platform were to fail. This implies that differential burst pressure could act as an Independent Protection Layer (IPL). This paper explores conditions that sections of a pipeline must satisfy in order to be considered as an IPL. A first order reliability method is outlined for determining the required target reliability. The application of this approach is described in a case study.

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