scholarly journals Selection of optimal vibration parameters molding reinforced concrete products

2020 ◽  
Vol 786 ◽  
pp. 012010
Author(s):  
V G Vasiliev
Keyword(s):  
Reinforced Concrete ◽  
Vibration Parameters ◽  
Selection Of

Development of Low-Activation Design Method for Reduction of Radioactive Waste Below Clearance Level

2008 ◽  
Author(s):  
Ken-Ichi Kimura ◽  
Akira Hasegawa ◽  
Katsumi Hayashi ◽  
Mikio Uematsu ◽  
Tomohiro Ogata ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Portland Cement ◽  
Power Plants ◽  
Raw Materials ◽  
Development Project ◽  
Radiation Shielding ◽  
Benchmark Calculation ◽  
Steel Bars ◽  
Clearance Level ◽  
Selection Of

Design methodology for reinforced concrete of nuclear power plants to reduce radioactive wastes in decommission phase has been developed. To realize this purpose, (1) development of raw materials database of cements, aggregates and steel bars on concentration of radioactive target elements, (2) trial production of low activation cements and steel bars based on the material database developed in (1), and (3) development of tools for estimation and prediction of the amount of radioactive elements in reactor shielding walls have been carried out. Radioactive analysis showed that Co and Eu were the major target elements which decide the radioactivity level of reinforced concrete from wide survey of raw materials for concrete (typically aggregates and cements). Material database for the contents of Co and Eu was developed based on the chemical analysis and radioactivation analysis. Upon the above survey and execution expreiment of concrete, six types of low-activation concrete are proposed for various radioactive portion in the plant. These concrete have a 1/10 – 1/300 rasioactivity compare to the ordinary concrete, which are assumed the concrete with Andesite aggregate and ordinary Portland cement. Baed on the above data base, it was clarified that the low activation cement would be successfully manufactured by adequate selection of raw materials. The prospect to produce the low-heat portland cement which would have a 1/3 radioactivity in comparison with conventioanl cements obtained by means of selection of limestone and natural gypsum. An attempte was carried out to produece low activation heavy-mortar which would have radioactivity below the clearance level when using at the radiation shielding wall of BWR. Characterization and optimization of consturction conditions with new additives have also been carried out. These two new raw materials for low-activation concrete are conducted in pre-manufacture size, and over the laboratry level. Boron added low-activation concrete are also carried out as extreamly high performance low-activation concrete. It was claryfied that the accurcy of calculation results of the radioactivity evaluation was very high compared to available benchmark calculation for the JPDR and commercial light water reactor. The specification of the mapping system for judging the activation classification was also developed by using the general-purpose radio activation calculation tool. This work is supported by a grant-in-aid of Innovative and Viable Nuclear Technology (IVNET) development project of Ministry of Economy, Trade and Industry, Japan.

Calibration of the Ontario Highway Bridge Design Code 1991 edition

1994 ◽  
Vol 21 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Andrzej S. Nowak ◽  
Hid N. Grouni
Keyword(s):  
Reinforced Concrete ◽  
Reliability Analysis ◽  
Prestressed Concrete ◽  
Highway Bridge ◽  
Live Load ◽  
Design Code ◽  
Reliability Indices ◽  
Resistance Factors ◽  
Load And Resistance Factors ◽  
Selection Of

The paper describes the calculation of load and resistance factors for the Ontario Highway Bridge Design Code (OHBDC) 1991 edition. The work involved the development of load and resistance models, the selection of the reliability analysis method, and the calculation of the reliability indices. The statistical models for load and resistance are reviewed. The considered load components include dead load, live load, and dynamic load. Resistance models are developed for girder bridges (steel, reinforced concrete, and prestressed concrete). A reliability analysis is performed for selected representative structures. Reliability indices are calculated using an iterative procedure. The calculations are performed for bridge girders designed using OHBDC 1983 edition. The resulting reliability indices are between 3 and 4 for steel girders and reinforced concrete T-beams, and between 3.5 and 5 for prestressed concrete girders. Lower values are observed for shorter spans (up to 30–40 m). The acceptance criterion in the selection of load and resistance factors is closeness to the target reliability level. The analysis confirmed the need to increase the design live load for shorter spans. Partial resistance factors are considered for steel and concrete. The criteria for the evaluation of existing bridges are based on the reliability analysis and economic considerations. Key words: bridge code, calibration, load factor, resistance factor, reliability index.

scholarly journals ESSENTIALS AND PROBLEMS SOLVING ALGORITHMS OF GENERAL STRENGTH THEORY OF RC ELEMENTS UNDER COMPLEX STRESS-STRAIN STATES

2018 ◽  
Vol 1 (50) ◽  
pp. 104-111
Author(s):  
V. P. Mitrofanov ◽  
N. M. Pinchuk N.M.
Keyword(s):  
Reinforced Concrete ◽  
Experimental Verification ◽  
Economic Effect ◽  
Complex Stress ◽  
Strength Theory ◽  
Software Complex ◽  
Manual Method ◽  
Concrete Elements ◽  
Lateral Reinforcement ◽  
Selection Of

The General strength theory of reinforced concrete elements (GSTRCE) passed the long and many-sided examination and showed the considerable advantages: well concordance with experiments, essential economic effect, solving method unity for different strength problems. Simple practical methods for calculating according to GSTRCE and available for use by designers and students are developed. The algorithms of calculating of two practically important problems are stated: strength control and selection of needed longitudinal and lateral reinforcement. Problems solving are represented by using «manual» method and well-known and easy-to-use software complex MS Excel. The results of experimental verification of GSTRCE are stated and the ones show well convergence of theoretical strength to experimental one.

Modeling and Simulation of Vibration-Assisted Extrusion Tapping of Internal Thread with Finite Element Method (FEM)

2012 ◽  
Vol 498 ◽  
pp. 183-188 ◽  
Author(s):  
Yong Yi Li ◽  
Sheng Dun Zhao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Material Flow ◽  
Internal Thread ◽  
The Finite Element Method ◽  
Forming Process ◽  
Effect Mechanism ◽  
Vibration Parameters ◽  
Selection Of ◽  
Element Method

This paper firstly introduces the principle and characteristic of traditional extrusion tapping of internal thread, elaborates the material flow law during tapping process. Then puts forward a novel process of vibration-assisted extrusion tapping of internal thread, explains the effect mechanism of vibration during extrusion tapping of internal thread. Finally, with the finite element method (FEM), the simplified model of extrusion tapping are built, and the simulation of thread forming process of traditional extrusion tapping of internal thread are conducted, furthermore, the characteristic and influencing law of different vibration parameters (include vibration frequency, amplitude and direction) of vibration-assisted extrusion tapping of internal thread are studied, and some practical results are obtained. The simulation results show that applying vibration to extrusion tapping of internal thread can reduce tapping torque and improve thread forming quality, the reasonable selection of vibration parameters are very crucial to this novel process.

scholarly journals THE INFLUENCE OF THE PRESTRESS OF REINFORCED STEEL ON THE BEHAVIOUR OF THE FLEXURAL ELEMENTS OF REINFORCED CONCRETE / ARMATŪROS IŠANKSTINIŲ ĮTEMPIŲ ĮTAKA GELŽBETONINIŲ LENKIAMŲJŲ ELEMENTŲ ELGSENAI

2013 ◽  
Vol 5 (5) ◽  
pp. 474-480
Author(s):  
Aidas Jokūbaitis
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Advantages And Disadvantages ◽  
Compressive Stresses ◽  
Reinforced Steel ◽  
Selection Of

This article briefly discusses the essence of prestressed concrete,its advantages and disadvantages. The analysis of prestress lossesis done according to different standards. The paper explainspretensioning force and selection of its eccentricity as well asanalyzes the influence of beam cracking according to limitationson concrete tensile and compressive stresses. Santrauka Publikacijoje glaustai aptarta įtemptojo gelžbetonio esmė, pranašumai ir trūkumai. Atlikta nuostolių vertinimo skirtingų normų metodikomis skaičiavimo analizė. Analizuojamas racionalios armatūros įtempimo jėgos ir jos pridėties ekscentriciteto parinkimas. Nagrinėjama leistinųjų betono tempimo ir gniuždymo įtempių įtaka sijų pleišėjimui.

Earthquake-Resisting System Selection Statistics for Reinforced Concrete Buildings

1995 ◽  
Vol 11 (1) ◽  
pp. 19-36 ◽  
Author(s):  
M. O. Eberhard ◽  
B. E. Meigs
Keyword(s):  
Reinforced Concrete ◽  
Pacific Northwest ◽  
The United States ◽  
Reinforced Concrete Buildings ◽  
Concrete Buildings ◽  
Geographical Regions ◽  
Consulting Firms ◽  
System Selection ◽  
Selection Of ◽  
Statistical Summary

To document current practice in selecting earthquake-resisting systems for reinforced concrete buildings, a survey was sent to consulting firms located in the United States, Canada, Chile, Colombia, Mexico and Peru. The respondents documented the earthquake-resisting systems for 4700 cast-in-place buildings that they had designed during the last five years. In addition, the respondents listed the factors that most affect the selection of earthquake-resisting systems. This paper presents a statistical summary of the responses and compares the responses collected from three U.S. geographical regions (Northern California, Pacific Northwest and Southern California) and among the six surveyed countries.

scholarly journals Focal Muscle Vibration for Stroke Rehabilitation: A Review of Vibration Parameters and Protocols

2020 ◽  
Vol 10 (22) ◽  
pp. 8270
Author(s):  
Hongwu Wang ◽  
Raghuveer Chandrashekhar ◽  
Josiah Rippetoe ◽  
Mustafa Ghazi
Keyword(s):  
Stroke Rehabilitation ◽  
Web Of Science ◽  
Narrative Synthesis ◽  
Muscle Vibration ◽  
Single Treatment ◽  
Exclusion Criteria ◽  
Treatment Frequency ◽  
Session Duration ◽  
Vibration Parameters ◽  
Selection Of

In this review, we present a narrative synthesis of studies on the use of focal muscle vibration (FMV) in stroke rehabilitation with a focus on vibration device, parameters, and protocols. A search was conducted via PubMed, SCOPUS, PEDro, REHABDATA, and Web of Science using the keywords “stroke and focal vibration” or “focal muscle vibration”. Inclusion and exclusion criteria to select the articles were determined. Twenty-two articles involving FMV and stroke were included in this review. Eight different vibration devices were used in the 19 articles that reported the vibration apparatuses. The vibration frequencies ranged from 30 Hz to 300 Hz with amplitudes ranging from 0.01 mm to 2 mm. The vibration treatment frequency ranged from a single treatment to 5 days/week. The session duration ranged from 14 s to 60 min/session with a duration of a single treatment to eight weeks. Twenty different muscles were targeted with 37 different outcome measures used to assess the effects of FMV. The clinical applications of FMV were not confirmed based on available evidence. More research is needed to improve the FMV technology, guide the selection of vibration parameters, optimize the vibration dosage, and develop standardized protocols for FMV therapy in patients with stroke.

scholarly journals Significant Guidance to Employ the Software to Analyze and Design the Reinforced Concrete Structures: State-Of-The-Art

2019 ◽  
Vol 8 (9) ◽  
pp. 1160-1169
Keyword(s):  
Reinforced Concrete ◽  
Structural Engineering ◽  
Final Decision ◽  
Design Codes ◽  
Construction Time ◽  
Rc Structures ◽  
Analysis And Design ◽  
Technical Specifications ◽  
Structural Engineers ◽  
Selection Of

Prevailing analysis and design of reinforced concrete (RC) structures is a critical stage in the construction industry to deliver the projects within the estimated construction time period and within the budget. The selection of suitable structural engineering software to perform the analysis and design tasks is not an easy matter of fact, especially with the existence of many specialized software in this domain such as Robot Structural Analysis, MIDAS Gen, SAP 2000, STAAD.PRO, Tekla Structural designer, S-Frame and many others. So a strong comparison between the existing software must be made before taking the final decision of selecting any software. The main goal of this paper is to present overall guidance for selection of the suitable software among the most common software used for the analysis and design of RC structures along with the supported design codes, analysis types and design modules incorporated in each software. The technical specifications, characteristics, application domains, incorporated structural design codes, limitation, technical popularity and capabilities of the existing most common used software were studied and compared. Based on the performed study, eleven software were selected and presented as a useful guideline for the structural engineers in the analysis and design of RC structures. In this paper, a complete guideline including the required technical information for structural engineers to choose the suitable software for analyzing and designing of the RC structures is presented.

Sign in / Sign up

Export Citation Format

Share Document