scholarly journals DEVELOPMENT OF SOFTWARE TO DETERMINE PRESSURES IN MULTICELULARSILOS WITH CONCENTRIC AND ECCENTRIC DISCHARGE

2020 ◽  
Vol 4 (2) ◽  
pp. 19-31
Author(s):  
Hellen Pinto Ferreira Deckers ◽  
Francisco Carlos Gomes ◽  
Larissa Pereira Barbosa Siva ◽  
Marília Gabriela Brandão Gonçalves ◽  
Marcelo Bastos Cordeiro
Keyword(s):  
Computer Program ◽  
Mass Flow ◽  
Computational Algorithm ◽  
International Standards ◽  
Graphical Form ◽  
Limit States ◽  
Development Application ◽  
Truncated Pyramid

A computer program for determining the pressures, horizontal and friction, in prismatic slender silos, with square section, eccentric hopper and mass flow, international codes taken as basis were: AS 3774 (1996), DIN 1055-6 (2005) and BS EN 1991-4 (2006) and the theories proposed by Safarian (1969) and Walker (1966). The development application was made possible by the development of a computational algorithm in programming “Borland Delphi”. The program was carried out for five silos projects with truncated pyramid form hopper considering the following eccentricities: 25%, 30%, 35% and 43%, as well as a concentric model for comparison. The computer program allowed SILOEXCENTRIC easily and quickly be applied to slender prismatic geometry of silos with concentric and eccentric hoppers. The results demonstrated the efficiency of the computer program for the proposed objectives So SILOEXCENTRIC results in pressures that are stored in files in “Notepad” format that may be accessed are generated. Besides files, various data are presented in graphical form, facilitating the assessment of horizontal pressures and friction, which proved adequate to international standards, considering the limit states.

Service Life of Concrete Structures

2020 ◽  
Vol 309 ◽  
pp. 267-271
Author(s):  
Milan Holicky ◽  
Jiří Kolísko
Keyword(s):  
Service Life ◽  
Concrete Structure ◽  
Limit State ◽  
Concrete Structures ◽  
Technical Specification ◽  
Working Life ◽  
Degradation Process ◽  
International Standards ◽  
Limit States ◽  
Existing Structures

The concept of service life of structures is included in international standards ISO (under the term Design Working Life), in the European document EN 1990 (Design Service Life) and in the upcoming document CEN for assessment of existing structures - Technical Specification TS (Remaining Working Life). The mentioned documents contain mainly material-independent provisions for the design and assessment of all types of structures and for any category of actions. The submitted paper includes the definition of service life (performance time) tser, which is extended for any concrete structure, considering the resistance of a structure R(t) and the effect of action S(t). Both the aggregate variables R(t) and S(t) are usually random variables significantly dependent on time t. Due to the random variability of the variables R(t) and S(t), the service life tser, needs to be related to the probability that the performance of the structure is weakened or completely eliminated. Basically, serviceability limit states (SLS) and ultimate limit states (ULS) should be considered. In the case of concrete structures another limit state corresponding to the beginning of a specific degradation process (corrosion of reinforcement), denoted tinit, may be important. In specific cases of buildings and bridges a functional (moral) service life may be taken into account. The paper includes also a practical example of assessing the remaining working life of a concrete structure.

ISUM for Offshore Frame Structures

2016 ◽  
Author(s):  
J. Amdahl ◽  
T. Holmas
Keyword(s):  
Computer Program ◽  
Oil And Gas ◽  
Frame Structures ◽  
Limit States ◽  
Environmental Loads ◽  
Offshore Industry

The paper presents the background and major ideas behind the computer program USFOS. The program is today widely used by the offshore industry to assess the resistance of oil and gas installations against abnormal environmental loads and accidental actions, such as ship collisions, fires and explosions. The assessment is normally performed in the accidental limit states; i.e. substantial yielding, buckling, partial collapse may take place, but the structure should maintain overall integrity. The features and concepts and models adopted in USFOS have also proved to be very useful in the analysis of totally different edifices. A few examples of this are given in the paper.

scholarly journals Horizontal pressures in cylindrical metal silos and comparison with different international standards

2013 ◽  
Vol 33 (4) ◽  
pp. 601-611 ◽  
Author(s):  
José W. B. do Nascimento ◽  
José P. Lopes Neto ◽  
Michael D. Montross
Keyword(s):  
Mass Flow ◽  
International Standards ◽  
Constant Speed ◽  
Flat Bottom ◽  
Cylindrical Metal ◽  
The One ◽  
Funnel Flow ◽  
Type Pressure

The focus of this research was to evaluate the horizontal pressures on a cylindrical metal silo of corrugated walls and flat bottom with 1.82m diameter and 5.4m high, and to compare the values with those obtained theoretically by the ISO 11697, EP 433 and AS 3774 standards. The silo was symmetrically filled and constant speed with wheat cv. soft red for two different height/diameter ratios (H/D) and was unloaded through three orifices with a diameter of 71.6mm, one concentric and two eccentrics. Horizontal pressures were measured on the walls of the silo at three positions using hydraulic type pressure cells. The results showed that shortly after the start of the unloading, there was a mass flow above the quota of H/D = 1.2, whereas below this quota funnel flow occurred. It can be said that the EP 433 standard was more appropriate to predict horizontal pressures in silos in H/D ratio = 1.0, with eccentric unloading. For the H/D ratio = 1.5, AS 3774 standard was the one that produced values closer to the experimental.

IMPACT OF PREDICTING BRITTLE FAILURE MODES ON SELECTION OF LIMIT STATES OF VERTICALLY-IRREGULAR TALL BUILDINGS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Aman Mwafy ◽  
Sayed Khalifa ◽  
Bilal El-Ariss
Keyword(s):  
Failure Modes ◽  
Limit State ◽  
Tall Buildings ◽  
International Standards ◽  
Performance Criteria ◽  
Far Field ◽  
Limit States ◽  
Earthquake Records ◽  
Irregular Buildings ◽  
Definition Of

The proper definition of structural failure of irregular structures is a critical element in building vulnerability assessment. Shear force demands may be the main cause of failure under earthquake loading. This increases the uncertainty related to the definition of the limit states of irregular buildings. The present study thus focuses on the assessment of brittle shear failure on the performance criteria of vertically irregular tall buildings. Five 50-story structures are designed using international standards to represent code-conforming tall buildings with main vertical irregularities. Detailed simulation models are used to assess the failure modes of the buildings under the effect of far-field and near-source earthquake records. Experimentally verified shear strength models are adopted to monitor the shear supply-demand response of the reference structures. Based on the comprehensive results obtained from incremental dynamic analyses, it is concluded that shear modeling is essential for the reliable assessment of vertically irregular buildings. The characteristics of earthquake records and the irregularity type significantly influence the limit states of the reference buildings. Unlike the behavior of the buildings under the far-field earthquake scenario, which is controlled by flexure, the collapse prevention limit state is significantly influenced by the member shear response under the effect of near-field earthquakes. Accordingly, improved limit state criteria are proposed, which supports the reliable earthquake loss estimation of tall buildings with different vertical irregularities.

scholarly journals Gas Turbine Inlet Air Cooling and the Effect on a Westinghouse 501D5 CT

1995 ◽  
Author(s):  
Chuck Kohlenberger
Keyword(s):  
Gas Turbine ◽  
Mass Flow ◽  
Heat Rate ◽  
International Standards ◽  
Air Cooling ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Turbine Inlet ◽  
Air Temperatures ◽  
Exhaust Gas Temperature

The temperature of the air entering a gas turbine prime mover has a dramatic effect on its performance, including output, heat rate, and exhaust gas temperature (EGT). These variations are easily observed in actual operation and by reference to generic gas turbine (GT) performance curves. The gross capacity increase of a GT operating at 40F (8C) inlet compared to operation at 102F (70C) is 28%. The gross reduction in heat rate for this 62F (16.7C) differential is 6%, and the exhaust gas temperature is reduced 5%. Since the overall mass flow through the GT is increased through the cooling process, the added energy available in the heat recovery steam generator (HRSG), is increased 8% The significant improvements in GT output and efficiency which can be achieved by maintaining lower inlet air temperatures encourage the manufacturer, systems engineer, owner, and operator of GT facilities to consider seriously the implementation of a gas turbine inlet air cooling (GTIAC) system. GTIAC systems have proven to produce some very excellent economic paybacks due to increased power output, EG mass flow, and reduced heat rates. Generic gross performance factors are plotted (See Figure 1) against inlet air temperature compared to International Standards Organization (ISO) conditions.

Standardized flexible end plate connections for steel beams

1985 ◽  
Vol 12 (4) ◽  
pp. 745-766 ◽  
Author(s):  
Gary J. Kriviak ◽  
D. J. Laurie Kennedy
Keyword(s):  
Computer Program ◽  
Empirical Relationship ◽  
Shear Capacity ◽  
Vertical Shear ◽  
Bottom Flange ◽  
Limit States ◽  
Interactive Computer Program ◽  
End Plate ◽  
Plate Connections ◽  
The Moment

A flexible end plate connection consists of a plate fastened to both sides of the web of a beam by fillet welds. Bolted field connections are used. The connection should transmit vertical shear and allow beam end rotations to occur without the development of significant moments. It is common practice to evaluate the shear capacity of these connections neglecting the presence of secondary forces, which can develop when the connection rotates.Existing analytical models of the moment–rotation behaviour correlate well with test results. These models consider both the flexural and membrane response of the connection in the upper tensile zone and use an empirical relationship to predict the force developed in the lower compression zone. In some tests undesirable impairment of connection flexiblity occurred when the bottom flange of the beam contacted the support.A limit states design model has been developed, which better predicts the moment–rotation characteristics of the connection and which also predicts the reduced vertical shear capacity of the connection due to secondary forces. Consideration of the secondary forces results in connections being designed with more consistent safety levels.An interactive computer program has been developed to design flexible end plate connections using this model. The program is attached to a data file containing the geometric properties of all standard steel flexural shapes available in North America. By specifying any of these shapes along with the desired material properties, loading conditions, connection geometry, and associated connection component costs, a designer can use the program to rapidly prepare customized connection designs or design tables. Key words: beams, connection, end plate, flexible, interactive computer program, joints, limit states design method, plastic deformation, shear strength, steel structures, structural analysis, structural design.

scholarly journals Inquiry and computer program Onko-Online: 25 years of clinical registry for breast cancer at the University Medical Centre Maribor

2019 ◽  
Vol 53 (3) ◽  
pp. 348-356
Author(s):  
Darja Arko ◽  
Iztok Takac
Keyword(s):  
Breast Cancer ◽  
Computer Program ◽  
Cancer Patients ◽  
Health Care Providers ◽  
Cancer Registries ◽  
International Standards ◽  
Care Providers ◽  
Breast Cancer Patients ◽  
Clinical Registry

Abstract Background High-quality routine care data collected in the clinical registry play a significant role in improving the management of cancer patients. Clinical cancer registries record important data in the course of cancer diagnosis, treatment, follow-up and survival. Analyses of such comprehensive data pool make it possible to improve the quality of patients care and compare with other health care providers. Methods The first inquiry at the Department of Gynaecologic and Breast Oncology of the then General Hospital Maribor to follow breast cancer patients has been introduced in 1994. Based on our experience and new approaches in breast cancer treatment, the context of inquiry has been changed and extended to the present form, which served as a model for developing a relevant computer programme named Onko-Online in 2014. Results During the 25-year period, we collected data from about 3,600 breast cancer patients. The computer program Onko-Online allowed for quick and reliable collection, processing and analysis of 167 different data of breast cancer patients including general information, medical history, diagnostics, treatment, and follow-up. Conclusions The clinical registry for breast cancer Onko-Online provides data that help us to improve diagnostics and treatment of breast cancer patients, organize the daily practice and to compare the results of our treatment to the national and international standards. A limitation of the registry is the potentially incomplete or incorrect data input by different healthcare providers, involved in the treatment of breast cancer patients.

scholarly journals ILT20 – an Upgraded Computer Program for Evaluation of Accelerated Leach Test Data of LLW in the Hungarian NPP Paks

2021 ◽  
Author(s):  
György Pátzay ◽  
János Nyőgér ◽  
Ottó Zsille ◽  
József Csurgai ◽  
Ferenc Feil ◽  
...  
Keyword(s):  
Differential Equation ◽  
Partial Differential Equation ◽  
Computer Program ◽  
Test Data ◽  
Computational Algorithm ◽  
Cylindrical Specimen ◽  
Accurate Method ◽  
Programming Environment ◽  
Waste Forms ◽  
Leach Test

Computer Program ILT15 was earlier developed to accompany a new leach test for solidified radioactive waste forms in the Hungarian NPP Paks. The program was designed to be used as a tool for performing the calculations necessary to analyze leach test data, a modelling program to determine if diffusion is the operating leaching mechanism (and, if not, to indicate other possible mechanisms), and a means to make extrapolations using the diffusion models. The program uses computational algorithm of ASTM C1308 standard. Now we have developed another computational algorithm based on a Partial Differential Equation (PDE) of a cylindrical specimen, solved the PDE by a Crank-Nicolson Finite Difference Method (FDM) and calculated by integration the eluted amount of a given component in time. The new solution more accurate method was integrated into the existing ILT15 computer program and the resulting new ILT20 program is able to calculate the Incremental/Cumulative Fraction Leached IFL/CFL) either by ASTM or PDE numerical solution methods.ILT20 program is written in C++ in the Borland C++ Builder programming environment. A detailed description of application of this upgraded modelling computer program is given.

scholarly journals Providing safety and reliability in the design of the offshore ice-resistant stationary oil and gas structures

Vestnik MGSU ◽  
2015 ◽  
pp. 167-177
Author(s):  
Valentin Aleksandrovich Polit’ko ◽  
Igor’ Grigor’evich Kantarzhi
Keyword(s):  
Oil And Gas ◽  
Design Method ◽  
Economic Consequences ◽  
International Standards ◽  
Limit States ◽  
Structure Reliability ◽  
The Social ◽  
Safety And Reliability ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Safety and reliability factors, assumed in Russian and international standards, as well as the main provisions of design of offshore oil and gas structures are considered in the article. The reasons for structures destruction are classified. The analysis showed that the main design provisions and methodology of calculations related to provision of safe and reliable operation of offshore oil and gas structures by different standards are not fundamentally different: the required degree of reliability of the structure is set depending on the social and economic consequences of possible hydrodynamic accidents; calculations are based on the limit states design method using partial safety factors; etc. However, the factors accounting the degree of the structure reliability, partial safety coefficients and load combinations coefficients differ in different standards and methodologies.

Effect of Aortic Arch Atherosclerotic Formations on Blood Mass Flow Distribution

1979 ◽  
Vol 101 (2) ◽  
pp. 96-104 ◽  
Author(s):  
Cz. M. Rodkiewicz ◽  
S. Zajac ◽  
W. T. Jedruch ◽  
W. T. M. Hsieh
Keyword(s):  
Reynolds Number ◽  
Computer Program ◽  
Aortic Arch ◽  
Mass Flow ◽  
Velocity Fluctuation ◽  
Flow Distribution ◽  
Arch Model ◽  
X Ray ◽  
Fluctuation Parameter

The effect of the aortic arch atherosclerotic formations on blood mass flow distribution is determined experimentally on the aortic arch model, derived from x-ray traces, for the average values of the governing parameters: Reynolds number, unsteadiness parameter, and velocity fluctuation parameter. A computer program incorporating the experimrntal data is developed, which predicts approximately the flow distribution for various arterial blockages.

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