Multiaxial Relaxation and Creep Damage Assessments—A Comparison of ASME N-47 and GLOSS Time-Scaling Methods

1993 ◽  
Vol 115 (1) ◽  
pp. 32-37 ◽  
Author(s):  
R. Seshadri
Keyword(s):  
Relaxation Process ◽  
Theoretical Basis ◽  
Creep Damage ◽  
Scaling Method ◽  
G Factor ◽  
Time Scaling ◽  
Scaling Methods ◽  
Asme Code

Two simplified methods for determining multiaxial relaxation and creep damage, the GLOSS time-scaling and the ASME Code Case N-47 method, are described in this paper. The theoretical basis and applicability of the methods to various pressure component configurations are discussed in detail. The G-factor in the ASME formula in effect speeds up or slows down the uniaxial relaxation process, similar to the GLOSS time-scaling method. The two methods are compared, and the differences are attributed to local follow-up not being accounted for in the ASME formula.

The Effect of Multiaxiality and Follow-Up on Creep Damage

1990 ◽  
Vol 112 (4) ◽  
pp. 378-385 ◽  
Author(s):  
R. Seshadri
Keyword(s):  
Relaxation Process ◽  
Approximate Method ◽  
Creep Damage ◽  
Local Stress ◽  
Relaxation Response ◽  
Relaxation Model ◽  
Stress Strain ◽  
Theoretical Formulation

A simple approximate method for estimating creep damage in pressure components experiencing multiaxial relaxation and follow-up is presented. The theoretical formulation essentially relates the relaxation process that accounts for multiaxiality and follow-up to the uniaxial relaxation model. The effect of follow-up is determined by studying the relaxation response on the Generalized Local Stress Strain (GLOSS) diagram. A procedure for partitioning creep damage into load and deformation-controlled fractions is also discussed. GLOSS analysis is applied to several component configurations that exhibit follow-up potential.

Assessing the effect of time-scaling methods on phylogeny-based analyses in the fossil record

Paleobiology ◽  
10.1666/13033 ◽  
2014 ◽  
Vol 40 (3) ◽  
pp. 331-351 ◽  
Author(s):  
David W. Bapst
Keyword(s):  
Fossil Record ◽  
Scaling Method ◽  
Short Branch ◽  
Time Scaling ◽  
Temporal Relationships ◽  
Branch Lengths ◽  
Scaling Methods ◽  
True Time ◽  
Fossil Data ◽  
Incomplete Sampling

Phylogeny-based approaches can be used to infer diversification dynamics and the rate and pattern of trait change. Applying these analyses to fossil data often requires time-scaling a cladogram of morphotaxon relationships. Although several time-scaling methods have been developed for this purpose, the incomplete sampling of the fossil record can distort the apparent timing of branching. It is unclear how well different time-scaling methods reconstruct the true temporal relationships or how any such inaccuracy could affect tree-based evolutionary analyses. I developed process-based simulations of the fossil record that allow the comparison of approximated time-scaled trees to true time-scaled trees. I used this simulation framework to test the effect of time-scaling methods on the fidelity of several commonly applied tree-based analyses, across a range of simulation conditions. When the fidelity of time-scaling methods differed, the stochastic “cal3”time-scaling method with ancestral assignment produced preferable results. Estimating rates and models of continuous trait evolution was particularly sensitive to bias from scenarios that forced the insertion of many short branch lengths, a bias that is not solved by any of the considered time-scaling methods in all scenarios. Thecal3method of time-scaling can be recommended as the preferred time-scaling method among those tested, but caution must be exercised because tree-based analyses are prone to easily overlooked biases.

RANCANGAN MODEL PENILAIAN KINERJA DENGAN METODE MANAJEMEN BERDASARKAN SASARAN (MANAGEMENT BY OBJECTIVE) DAN PENSKALAAN GRAFIK DI PT ACI

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Linda Mora Siregar
Keyword(s):  
Performance Appraisal ◽  
Job Analysis ◽  
Scaling Method ◽  
Scaling Methods ◽  
Questionnaire Method ◽  
A Performance

The purpose of this study is to design a performance appraisal model more effectively in accordance with the company's vision and mission, namely by combining management methods based on objectives (management by objective) and graph scaling methods. In the preparation of performance appraisal models with management methods based on objectives (management by objective) and graph scaling methods, carried out with several stages, namely the first stage is planning the making of performance appraisal models, the second is job analysis, third is the preparation of management methods based on objectives (management by objective), the fourth is the preparation of the scaling method and the fifth is the preparation of the performance appraisal form. The making of this performance appraisal design will use a questionnaire method, observation and also interviews to obtain and collect information and data.  Keywords: Performance Appraisal, Management Methods, Graph Scaling.   Tujuan penelitian ini adalah untuk merancang model penilaian kinerja secara lebih efektif sesuai dengan visi dan misi perusahaan, yaitu dengan menggabungkan metode manajemen berdasarkan sasaran (management by objective) dan metode penskalaan grafik. Dalam penyusunan model penilaian kinerja dengan metode manajemen berdasarkan sasaran (management by objective) dan metode penskalaan grafik, dilakukan dengan beberapa tahapan yaitu tahap pertama adalah perencanaan pembuatan model penilaian kinerja, kedua analisis jabatan, ketiga penyusunan metode manajemen berdasarkan sasaran (management by objective), keempat penyusunan metode penskalaan grafik dan kelima adalah penyusunan formulir penilaian kinerja. Pembuatan rancangan penilaian kinerja ini akan menggunakan metode kuesioner, observasi dan juga wawancara untuk mendapatkan dan mengumpulkan informasi dan data.   Kata Kunci: Penilaian kinerja, Metode Manajemen, Penskalaan Grafik.

Clinical Value of Computer-Assisted Taylor Three-dimensional External Fixation in the Treatment of Tibiofibular Fracture (Preprint)

2020 ◽  
Author(s):  
Hongfeng Sheng ◽  
Weixing Xu ◽  
Bin Xu ◽  
Hongpu Song ◽  
Di Lu ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Internal Fixation ◽  
External Fixation ◽  
External Fixator ◽  
Theoretical Basis ◽  
New Technology ◽  
Three Dimensional ◽  
Computer Assisted ◽  
Clinical Value

UNSTRUCTURED The retrospective study of Taylor's three-dimensional external fixator for the treatment of tibiofibular fractures provides a theoretical basis for the application of this technology. The paper collected 28 patients with tibiofibular fractures from the Department of Orthopaedics in our hospital from March 2015 to June 2018. After the treatment, the follow-up evaluation of Taylor's three-dimensional external fixator for the treatment of tibiofibular fractures and concurrency the incidence of the disease, as well as the efficacy and occurrence of the internal fixation of the treatment of tibial fractures in our hospital. The results showed that Taylor's three-dimensional external fixator was superior to orthopaedics in the treatment of tibiofibular fractures in terms of efficacy and complications. To this end, the thesis research can be concluded as follows: Taylor three-dimensional external fixation in the treatment of tibiofibular fractures is more effective, and the incidence of occurrence is low, is a new technology for the treatment of tibiofibular fractures, it is worthy of clinical promotion.

scholarly journals A comparison of the modern Lie scaling method to classical scaling techniques

2016 ◽  
Vol 20 (7) ◽  
pp. 2669-2678 ◽  
Author(s):  
James Polsinelli ◽  
M. Levent Kavvas
Keyword(s):  
Lie Group ◽  
Overland Flow ◽  
New Technology ◽  
Scaling Method ◽  
Lie Group Of Transformations ◽  
Key Points ◽  
Scaling Transformation ◽  
Scaling Models ◽  
Scaling Methods ◽  
Channel Hydraulics

Abstract. In the past 2 decades a new modern scaling technique has emerged from the highly developed theory on the Lie group of transformations. This new method has been applied by engineers to several problems in hydrology and hydraulics, including but not limited to overland flow, groundwater dynamics, sediment transport, and open channel hydraulics. This study attempts to clarify the relationship this new technology has with the classical scaling method based on dimensional analysis, non-dimensionalization, and the Vaschy–Buckingham-Π theorem. Key points of the Lie group theory, and the application of the Lie scaling transformation, are outlined and a comparison is made with two classical scaling models through two examples: unconfined groundwater flow and contaminant transport. The Lie scaling method produces an invariant scaling transformation of the prototype variables, which ensures the dynamics between the model and prototype systems will be preserved. Lie scaling can also be used to determine the conditions under which a complete model is dynamically, kinematically, and geometrically similar to the prototype phenomenon. Similarities between the Lie and classical scaling methods are explained, and the relative strengths and weaknesses of the techniques are discussed.

Components Map Generation of Gas Turbine Engine Using Genetic Algorithms and Engine Performance Deck Data

2006 ◽  
Vol 129 (2) ◽  
pp. 312-317 ◽  
Author(s):  
Changduk Kong ◽  
Jayoung Ki
Keyword(s):  
Experimental Data ◽  
Genetic Algorithms ◽  
Gas Turbine ◽  
Test Data ◽  
Engine Performance ◽  
Scaling Method ◽  
Turbine Engine ◽  
Scaling Methods ◽  
Map Generation ◽  
Component Map

In order to estimate the gas turbine engine performance precisely, the component maps containing their own performance characteristics should be used. Because the components map is an engine manufacturer’s propriety obtained from many experimental tests with high cost, they are not provided to the customer generally. Some scaling methods for gas turbine component maps using experimental data or data partially given by engine manufacturers had been proposed in a previous study. Among them the map generation method using experimental data and genetic algorithms had showed the possibility of composing the component maps from some random test data. However not only does this method need more experimental data to obtain more realistic component maps but it also requires some more calculation time to treat the additional random test data by the component map generation program. Moreover some unnecessary test data may introduced to generate inaccuracy in component maps. The map generation method called the system identification method using partially given data from the engine manufacturer (Kong and Ki, 2003, ASME J. Eng. Gas Turbines Power, 125, 958–979) can improve the traditional scaling methods by multiplying the scaling factors at design point to off-design point data of the original performance maps, but some reference map data at off-design points should be needed. In this study a component map generation method, which may identify the component map conversely from some calculation results of a performance deck provided by the engine manufacturer using the genetic algorithms, was newly proposed to overcome the previous difficulties. As a demonstration example for this study, the PW206C turbo shaft engine for the tilt rotor type smart unmanned aerial vehicle which has been developed by Korea Aerospace Research Institute was used. In order to verify the proposed method, steady-state performance analysis results using the newly generated component maps were compared with them performed by the Estimated Engine Performance Program deck provided by the engine manufacturer. The performance results using the identified maps were also compared with them using the traditional scaling method. In this investigation, it was found that the newly proposed map generation method would be more effective than the traditional scaling method and the methods explained above.

Comparison of R5 and ASME NH Creep-Fatigue Damage Assessment Methodologies

2013 ◽  
Author(s):  
Michael Sheridan ◽  
David Knowles ◽  
Oliver Montgomery
Keyword(s):  
Fatigue Damage ◽  
Structural Integrity ◽  
Temperature Response ◽  
Creep Damage ◽  
Basic Principles ◽  
Metallic Structures ◽  
Reference Stress ◽  
Creep Fatigue ◽  
Design Generation

The R5 volume 2/3 procedures [1] were developed by British Energy (now EDF Energy) to assess the high temperature response of uncracked metallic structures under steady state or cyclic loading. They contain the basic principles of: • Application of reference stress methods • Consideration of elastic follow up • A ductility exhaustion approach to calculate creep damage accumulation. These considerations represent a fundamental distinction from ASME BPVC Section III, Subsection NH [2]. This paper draws on literature review and experience to explain the principal differences in the limits of application, cycle construction and damage calculation between these codes/procedures focusing on creep-fatigue damage determination. The implications of the differences between the codes and standards are explored. The output of this work is aimed at two groups of structural integrity engineers; those using these codes and standards to assess existing conventional and nuclear plant, and also those looking to ASME and R5 to design Generation IV PWRs with design temperatures much elevated from those of Generation III and III+. The conclusions from this paper offer some practical guidance to structural integrity engineers which may assist in selecting the more appropriate procedure to assess creep-fatigue damage for a particular situation.

A New Scaling Method for Component Maps of Gas Turbine Using System Identification

2002 ◽  
Author(s):  
Changduk Kong ◽  
Jayoung Ki ◽  
Myoungcheol Kang
Keyword(s):  
Gas Turbine ◽  
Engine Performance ◽  
Operating Conditions ◽  
Scaling Method ◽  
Design Point ◽  
The Real ◽  
Simulated Performance ◽  
Flight Envelope ◽  
Scaling Methods ◽  
Performance Error

A scaling method for characteristics of gas turbine components using experimental data or partially given data from engine manufacturers was newly proposed. In case of currently used traditional scaling methods, the predicted performance around the on-design point may be well agreed with the real engine performance, but the simulated performance at off-design points far away from the on-design point may not be well agreed with the real engine performance generally. It would be caused that component scaling factors, which were obtained at on-design point, is also used at all other operating points and component maps are derived from different known engine components. Therefore to minimize the analyzed performance error in the this study, firstly component maps are constructed by identifying performances given by engine manufacturers at some operating conditions, then the simulated performance using the identified maps is compared with performances using currently used scaling methods. In comparison, the analyzed performance using the currently used traditional scaling method was well agreed with the real engine performance at the on-design point but had maximum 12% error at off design points within the flight envelope of a calculation example turboprop engine. However the performance result using the newly proposed scaling method had maximum 6% reasonable error even at all flight envelope.

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