Numerical simulations of preliminary state of stress in bundles of metal sheets on the guillotine

2017 ◽  
Vol 85 (1) ◽  
pp. 14-23 ◽  
Author(s):  
J. Kaczmarczyk
Keyword(s):  
Numerical Simulations ◽  
Experimental Studies ◽  
Cutting Parameters ◽  
Cutting Process ◽  
Main Task ◽  
Force Loading ◽  
State Of Stress ◽  
Metal Sheets ◽  
Optimum Cutting ◽  
Selection Of

Purpose: The work is aimed at determination of the influence of selected technological parameters on the preliminary state of stress in bundles of metal sheets being compressed by the pressure beam and submitted to the cutting process on a guillotine. Design/methodology/approach: The numerical simulations concerning the preliminary state of stress in the bundle of sheets were conducted by means of the finite element method and the computer system MSC.Patran with the computational module MSC.Marc. The experimental studies concerning the influence of a force loading the pressure beam on the quality of metal sheets were carried out using scanning electron microscopy. Findings: Possibilities of finding the optimum cutting parameters to maximise the values of preliminary state of stress in the bundle of metal sheets subjected to cutting. Higher values of stresses in the bundle coming from loading the pressure beam on the one hand decrease the maximum values of cutting force and thereby facilitate the performance of the cutting process, however on the other hand too high values of stresses might damage the surface of the top sheet in a bundle. Research limitations/implications: The main task of the presented research concerns the reduction of the maximum force generated on a knife during the cutting process. It is possible by increasing the values of preliminary state of stress realized in practice by applying higher values of a force loading the pressure beam. The force should not be too high in order to avoid damaging of the top sheet in the bundle loading by the pressure beam. Practical implications: The appropriate selection of the cutting parameters on account of preliminary state of stress in the bundle of sheets is essential in terms of industrial economy. It enables reducing the amount of waste caused by defects in bundles of sheets and decreases wear of the cutting tool. The research has been conducted in order to reduce the number of randomly occurring defects during cutting of metal sheets on a guillotine. Originality/value: The results acquired from the research facilitate selection of the best parameter settings required for conducting the optimum cutting process on a guillotine. The optimum set of cutting parameters leads to the reduction of defects’ number occurring during the process.

Experimental Studies on the Influence of Cutting Parameters on Thrust Force and Torque during Drilling of GFRP with SiC Fillers

2010 ◽  
Vol 443 ◽  
pp. 342-346 ◽  
Author(s):  
Mouleeswaran Senthil Kumar ◽  
Vijayan Krishnaraj
Keyword(s):  
Thrust Force ◽  
Experimental Studies ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Gfrp Composites ◽  
Glass Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic ◽  
Twist Drills ◽  
Selection Of

The paper discusses the influence of cutting parameters such as cutting speed, feed rate and point angle on thrust force and torque while drilling of Glass Fiber Reinforced Plastic (GFRP) composites with Silican Carbide (SiC) fillers. The experiments were conducted during the drilling of GFRP with SiC fillers using four standard twist drills of point angles 90º, 100º, 110º and 120º. Conclusions thus drawn are presented and can be useful for the selection of the best cutting parameters.

SISTEM PENDUKUNG KEPUTUSAN PEMILIHAN GURU BERPRESTASI KOTA MEDAN MENERAPKAN METODE PREFERENCES SELECTION INDEX (STUDI KASUS : DINAS PENDIDIKAN KOTA MEDAN)

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Fajar Syahputra ◽  
Mesran Mesran ◽  
Ikhwan Lubis ◽  
Agus Perdana Windarto
Keyword(s):  
Decision Making ◽  
Decision Support ◽  
Decision Support System ◽  
Support System ◽  
Formal Education ◽  
Basic Education ◽  
Selection Index ◽  
Main Task ◽  
Selection Of

The teacher is a major milestone in the world of education, the ability and achievement of students cannot be separated from the role of a teacher in teaching and guiding students. Based on the Law of the Republic of Indonesia No. 14 of 2005 concerning Teachers and Lecturers, in Article 1 explained that teachers are professional educators with the main task of educating, teaching, guiding, directing, training, evaluating, and evaluating students in early childhood education through formal education, basic education and education medium. Whereas in Article 4 of the Act, it is explained that the position of teachers as professionals serves to enhance the dignity and role of teachers as learning agents to function to improve the quality of national education.Decision making is an election process, among various alternatives that aim to meet one or several targets. The decision-making system has 4 phases, namely intelligence, design, choice and implementation. These phases are the basis for decision making, which ends with a recommendation.The Preferences Selection Index (PSI) method is a rarely used decision support system method. This method is a method developed by stevanie and Bhatt (2010) to solve the Multi Criteria Decision Making (MCDM). With the right consideration, this method can be one of the tools to determine policies in decision-making systems, especially the selection of outstanding teachers. Determination of policies taken as a basis for decision making, must use criteria that can be defined clearly and objectively.Keywords: Decision Support System, PSI, Selection of Achieving Teachers

Numerical analysis of heat flow in oxy-ethylene flame cutting of steel plate

2016 ◽  
Vol 232 (4) ◽  
pp. 742-751 ◽  
Author(s):  
Kang-Yul Bae ◽  
Young-Soo Yang ◽  
Myung-Su Yi ◽  
Chang-Woo Park
Keyword(s):  
Numerical Simulation ◽  
Heat Flow ◽  
Heat Affected Zone ◽  
Steel Plate ◽  
Cutting Parameters ◽  
Cutting Process ◽  
Heat Sources ◽  
Power Functions ◽  
Severe Problem ◽  
Ethylene Flame

To manufacture a steel structure, in the first step, raw steel plate needs to be cut into proper sizes. Oxy-fuel flame is widely used in the cutting process due to its flexibility with respect to accessibility, plate thickness, cost, and material handling. However, the deformation caused by the cutting process frequently becomes a severe problem for the next process in the production of steel product. To decrease the deformation, the thermo-elasto-plastic behavior of the steel plate in the cutting process should be analyzed in advance. In this study, heat sources in oxy-ethylene flame cutting of steel plate were modeled first, and the heat flow in the steel plate was then analyzed by the models of the heat sources using a numerical simulation based on the finite element method. To verify the analysis by the numerical simulation including the models, a series of experiments were performed, and the temperature histories at several points on the steel plate during the cutting process were measured. Moreover, the predicted sizes of the heat-affected zone by the numerical simulations according to the variation in the cutting parameters were compared to the experimental results. The power functions of the relationship between the sizes of the heat-affected zone and cutting parameters were obtained by the recursion analysis using the correlation between the results and parameters. The results of the numerical simulation showed good agreement with those of the experiments, indicating that the proposed models of the heat sources and thermal analysis were feasible to analyze the heat flow in the steel plate during the cutting process.

scholarly journals Functional Method of Designing Self-Compacting Concrete

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 267
Author(s):  
Tomasz Rudnicki
Keyword(s):  
Coarse Aggregate ◽  
Cement Mortar ◽  
Experimental Studies ◽  
Functional Method ◽  
Structural Viscosity ◽  
Self Compacting Concrete ◽  
Theoretical Assumptions ◽  
Concrete Mix ◽  
Selection Of ◽  
Double Coating

The article presents a new functional method of designing self-compacting concrete (SCC). The assumptions of the functional method of designing self-compacting concrete were based on the double coating assumption (i.e., it was assumed that the grains of coarse aggregate were coated with a layer of cement mortar, whereas the grains of sand with cement paste). The proposed method is composed of four stages, each of which is responsible for the selection of a different component of the concrete mix. The proposed designing procedure takes into consideration such a selection of the mineral skeleton in terms of the volumetric saturation of the mineral skeleton, which prevents the blocking of aggregate grains, and the designed liquid phase demonstrated high structural viscosity and low yield stress. The performed experimental studies, the simulation of the elaborated mathematical model fully allowed for the verification of the theoretical assumptions that are the basis for the development of the method of designing self-compacting concrete.

scholarly journals Adaptive Control Structure with Neural Data Processing Applied for Electrical Drive with Elastic Shaft

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3389
Author(s):  
Marcin Kamiński ◽  
Krzysztof Szabat
Keyword(s):  
Neural Network ◽  
Adaptive Control ◽  
Dynamic Properties ◽  
Experimental Studies ◽  
Drive System ◽  
Particle Swarm Optimizer ◽  
The Neural Network ◽  
Control Concept ◽  
Constant Coefficients ◽  
Selection Of

This paper presents issues related to the adaptive control of the drive system with an elastic clutch connecting the main motor and the load machine. Firstly, the problems and the main algorithms often implemented for the mentioned object are analyzed. Then, the control concept based on the RNN (recurrent neural network) for the drive system with the flexible coupling is thoroughly described. For this purpose, an adaptive model inspired by the Elman model is selected, which is related to internal feedback in the neural network. The indicated feature improves the processing of dynamic signals. During the design process, for the selection of constant coefficients of the controller, the PSO (particle swarm optimizer) is applied. Moreover, in order to obtain better dynamic properties and improve work in real conditions, one model based on the ADALINE (adaptive linear neuron) is introduced into the structure. Details of the algorithm used for the weights’ adaptation are presented (including stability analysis) to perform the shaft torque signal filtering. The effectiveness of the proposed approach is examined through simulation and experimental studies.

Constraints on the accuracy of messenger RNA movement

1985 ◽  
Vol 18 (4) ◽  
pp. 423-450 ◽  
Author(s):  
C. G. Kurland ◽  
Måns Ehrenberg
Keyword(s):  
Messenger Rna ◽  
Experimental Studies ◽  
Physical Problem ◽  
Translational Accuracy ◽  
Trna Species ◽  
Selection Of

SUMMARYTheoretical as well as experimental studies of translational accuracy have most often been concerned with the selection of aminoacyl-tRNA by codon-programmed ribosomes. The selection of the successive codons on the mRNA has received much less attention, probably because it represents both conceptually and experimentally, a much more demanding physical problem. Nevertheless, it would seem that errors in the selection of the codon are potentially much more destructive than errors in selection of aminoacyl-tRNA species. This can be appreciated from the following.

scholarly journals Collective Losses of Low Power Cage Induction Motors—A New Approach

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1749
Author(s):  
Elzbieta Szychta ◽  
Leszek Szychta
Keyword(s):  
Control System ◽  
Experimental Studies ◽  
Complex Problem ◽  
Accurate Estimation ◽  
New Approach ◽  
Water Pumping ◽  
Efficiency Control ◽  
Interacting Systems ◽  
Cage Induction Motor ◽  
Selection Of

Energy efficiency of systems of water pumping is a complex problem since efficiency of two distinct interacting systems needs to be combined: water and power supply. This paper introduces a non-intrusive method of calculating the so-called “collective losses” of a cage induction motor. The term “collective losses”, which the authors define, allows for accurate estimation of motor efficiency. Control system of a pump determines operating point of a pumping station, and thus its efficiency. General estimated performance characteristics of a motor, components of a control system, are assumed to serve selection of a range of pumping speed variations. Rotational speed has a direct effect on motor load torque, pump power and head, and thus on motor performance. Hellwig’s statistical method was used to specify characteristics of estimated collective losses on the basis of experimental studies of 21 motors rated at up to 2.2 kW. The results of simulations and experiments are used to verify validity and efficiency of the suggested method. The method is non-intrusive, simple to use, and requires minimum data.

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