scholarly journals UNIVERSAL METHOD OF CALCULATION OF MULTISPAN BEAMS

2021 ◽  
Vol 1 (38) ◽  
pp. 40-47
Author(s):  
V. Ropay ◽  
L. Telipko ◽  
O. Romanyuk
Keyword(s):  
Optimal Solution ◽  
Software Systems ◽  
Engineering Practice ◽  
Universal Method ◽  
Bending Moments ◽  
Present Stage ◽  
Universal Equation ◽  
Method Of Calculation ◽  
Additional Equation ◽  
Supporting Structures

The supporting structures of machines and mechanisms of metallurgical equipment, which are characterized by large dimensions, in the calculation scheme can be reduced to multispan beams, which are statically indeterminate. Traditionally, the disclosure of their static uncertainty is based on the graphoanalytical method, which is called "Equation of 3 moments". According to this method, the equations of three points are solved by constructing intermediate epure of bending moments, finding their areas and position of the centers of gravity. These procedures lead to an unreasonable increase in time to solve the problem. It is advisable to have an analytical method for detecting static uncertainty of multispan beams, which would be free from graphical constructions and would significantly reduce the time to solve the problem. At the present stage, the calculation of complex spatial structures is carried out using the calculation and software systems "LIRA", "SCAD" and others. However, this in no way limits the need for the application in engineering practice of simple analytical methods, which include a universal method for detecting static indeterminateness of multispan beams. Additional, to the static equations, the equations of displacement are compiled using the universal equation of the bent axis of the beam, and the number of beams can be any large. Different variants of boundary conditions are considered. The results of the considered examples prove the independence of the values ​of "extra" unknown from the stiffness of the beam.             The universal method is quite optimal, as it uses a very simple universal equation of the bent axis of the beam and, with each subsequent additional equation of displacement differs from the previous one only by adding another item with a new load. This approach provides the optimal solution to almost any problem, by revealing the static indeterminateness of multispan beams.

scholarly journals Hierarchical System Decomposition Using Genetic Algorithm for Future Sustainable Computing

2020 ◽  
Vol 12 (6) ◽  
pp. 2177
Author(s):  
Jun-Ho Huh ◽  
Jimin Hwa ◽  
Yeong-Seok Seo
Keyword(s):  
Genetic Algorithm ◽  
Software Architecture ◽  
Large Scale ◽  
Structural Characteristics ◽  
Optimal Solution ◽  
Hill Climbing ◽  
Software Systems ◽  
Small Scale ◽  
Hill Climbing Algorithm ◽  
Architecture Management

A Hierarchical Subsystem Decomposition (HSD) is of great help in understanding large-scale software systems from the software architecture level. However, due to the lack of software architecture management, HSD documentations are often outdated, or they disappear in the course of repeated changes of a software system. Thus, in this paper, we propose a new approach for recovering HSD according to the intended design criteria based on a genetic algorithm to find an optimal solution. Experiments are performed to evaluate the proposed approach using two open source software systems with the 14 fitness functions of the genetic algorithm (GA). The HSDs recovered by our approach have different structural characteristics according to objectives. In the analysis on our GA operators, crossover contributes to a relatively large improvement in the early phase of a search. Mutation renders small-scale improvement in the whole search. Our GA is compared with a Hill-Climbing algorithm (HC) implemented by our GA operators. Although it is still in the primitive stage, our GA leads to higher-quality HSDs than HC. The experimental results indicate that the proposed approach delivers better performance than the existing approach.

Design of Crane Hooks and Other Components of Lifting Gear

1934 ◽  
Vol 128 (1) ◽  
pp. 253-360 ◽  
Author(s):  
H. J. Gough ◽  
H. L. Cox ◽  
D. G. Sopwith
Keyword(s):  
Fatigue Testing ◽  
Ductile Material ◽  
Radius Of Curvature ◽  
Stress System ◽  
Bending Moments ◽  
Approximate Methods ◽  
Method Of Calculation ◽  
Centre Line ◽  
Set Up ◽  
Chain Links

Most lifting gear components consist essentially of curved beams of very ductile material, the radius of curvature often being small in comparison with the dimensions of the beam. In addition, in rings, chain links, etc., the distribution of bending moment is not directly calculable from the values of the applied loads, but is influenced also by the condition that the centre line of the section of the component must remain continuous when under load. The design of lifting gear components requires, therefore, the determination of the bending moments, etc., set up, the calculation of the stresses due to these bending moments, etc., and the consideration of the modification to the stress system consequent upon yielding in parts of the components. The effect of the curvature of the centre line of the component on the distribution of stress is first discussed, the method of calculation for different forms of beam section being indicated, and the best form of section investigated. The effect of yielding is next considered. It is shown that, if any portion of the component yields under load, the removal of the load will leave this portion in a state of stress of opposite sign to that under which it yielded, and it is concluded that calculated stresses even as high as the sum of the yield stresses in tension and compression may be actually set up in the material as ranges of stress without causing continuous plastic deformation. The general method of calculating the bending moments in rings and links, etc., is demonstrated and comparison is made between exact and approximate methods. General formulæ for egg links (including rings and chain links), studded links, and eyebolts are obtained and typical examples, drawn from recent British Standard Specifications, are worked out. The results of tests on components designed according to the general principles of the paper are described and the use of fatigue testing both in determining the true factor of safety and as an experimental check on the calculations is demonstrated.

scholarly journals The revised method for calculating of the optimal train control mode

2019 ◽  
Vol 51 (3) ◽  
pp. 21-34
Author(s):  
Konstantyn I. Zhelieznov ◽  
Artem S. Akulov ◽  
Oleksandr M. Zabolotniy ◽  
Lyudmila V. Ursulyak ◽  
Evgenij V. Chabanuk ◽  
...  
Keyword(s):  
Calculation Method ◽  
Equations Of Motion ◽  
Optimal Solution ◽  
Control Mode ◽  
Practical Significance ◽  
Controlled System ◽  
Methodology Development ◽  
Method Of Calculation ◽  
Significant Time ◽  
Train Control

Development of a method for calculating the optimal mode of conducting a train in terms of energy saving meet the safety requirements and schedules. The method of calculation must solve the assigned tasks without significant time spent on the calculation. To implement this method of calculation was used a simplified model of the train as a controlled system. The existing mathematical and algorithmic methods for solving isoperimetric problems of finding the optimal solution in the presence of restrictions on resources were the information base for methodology development. Scientific works of domestic and foreign scientists, professional periodicals, materials of scientific and practical conferences, methodical and normative materials, currently in force on Ukrainian Railways. The results of these studies were used to create simulators on the basis of computer technology for the training of locomotive drivers. The scientific novelty of the proposed calculation method consists in applying the simplified calculations of the status of the train as a controlled system, without the use of differential equations of motion that allows to significantly increase the speed of the calculations. This, in turn, will solve the problems of finding optimal control in real time, taking into account changing conditions during the movement of the train. The practical significance of the obtained results is the use of such a calculation method that does not require significant time for its implementation and can be used as a subsystem of the on-board train control system capable of per-forming calculations taking into account changes in the current train situation.

scholarly journals Grouping and analysis of chair quality and their basic elements

2009 ◽  
pp. 147-154 ◽  
Author(s):  
Dusan Skakic ◽  
Igor Dzincic
Keyword(s):  
Finite Element Method ◽  
Decision Making ◽  
Finite Element ◽  
Numerical Optimization ◽  
Optimal Solution ◽  
Engineering Practice ◽  
The Finite Element Method ◽  
Wide Range ◽  
Decision Making Processes ◽  
Selection Of

Both the scientific experience and the engineering practice indicate that the decision making processes in the course of solving complex designing problems require an analysis of a great number of different construction variants. These types of decision-making processes are time consuming and do not always result in the selection of an optimal solution. That is why the methods of numerical optimization are applied in a wide range of technical sciences to assist in the selection of the best solution. The first step in solving the problem by using the Finite element method is to determine the type of chair earmarked for modeling, and to determine the dimensions of the chair elements.

METHOD OF CALCULATION OF THERMAL PROPERTIES FOR BUILDING ENVELOPES WITH SCREEN INSULATION

2016 ◽  
Vol 6 (1) ◽  
pp. 4-7 ◽  
Author(s):  
Yuri Serafimovich VYTCHIKOV ◽  
Mikhail Evgen'evich SAPAREV
Keyword(s):  
Thermal Properties ◽  
Thermal Conduction ◽  
Numerical Data ◽  
Engineering Practice ◽  
Building Envelopes ◽  
Method Of Calculation ◽  
Thermal Screen ◽  
Air Ventilation ◽  
Resources Conservation ◽  
The Moment

The present research is performed in the framework of energy and resources conservation measures promotion in civil engineering. It introduces the perspectives of using thermal isolation in outer building envelopes and in air ventilation and conditioning systems insulation. The paper analyses the use of thermal screen isolation in building envelopes and air ventilation systems and proves that at the moment there is no methodology able to calculate these constructions in the existing engineering practice. The authors conducted a physical experiment to get reliable data on thermal screen isolation properties taking expanded polyethylene as a sample material. The results of the experiment as well as the obtained thermal conduction coefficient are presented in the paper. On the basis of the numerical data the authors introduce a verified methodology of calculation of thermal properties for building envelopes with screen insulation.

Lane’s Algorithm Revisited

2020 ◽  
Author(s):  
Marcos Goycoolea ◽  
Patricio Lamas ◽  
Bernardo K. Pagnoncelli ◽  
Adriana Piazza
Keyword(s):  
Optimality Conditions ◽  
Continuous Time ◽  
Mining Industry ◽  
Optimal Solution ◽  
Open Pit ◽  
Mixed Integer ◽  
Software Systems ◽  
Real World Data ◽  
Data Set ◽  
Processed Material

In 1964, Kenneth Lane proposed an algorithm to optimize the production schedule of a single-metal, single-processor open pit mine. For this, he proposed a policy based on varying, over time, the so-called “cutoff grade”—or grade threshold used to determine if extracted material should be ore (processed material) or waste (thrown away). Lane’s algorithm had a profound impact on the mining industry. However, though it has been used in multiple commercial software systems and has traditionally been taught to every aspiring mining engineer, it is widely considered a heuristic, and little is known regarding the quality of the solutions it produces. In this paper, we formally study Lane’s problem. We show that Lane’s algorithm can be viewed as an approximate dynamic programming scheme and that Lane’s optimality conditions can be formally derived in two different ways: by considering a variant of the problem where the future value function is linearly approximated or by deriving the optimality conditions of a continuous-time version of the problem. We further show that Lane’s algorithm can naturally be extended to this continuous-time version of the problem and that when this algorithm converges, it converges to an optimal solution. Finally, through a reformulation, we show that Lane’s original problem can be solved using convex mixed-integer programming. Though hypothetical counterexamples can be constructed, computational experiments prove that Lane’s algorithm can produce the optimal solution in every real-world data set tested, thereby lending solid support for its practical application. This paper was accepted by Chung Piaw Teo, optimization.

The Analytical Calculation of Ship Bending Moments in Regular Waves

1958 ◽  
Vol 2 (02) ◽  
pp. 20-29
Author(s):  
Winnifred R. Jacobs
Keyword(s):  
Analytical Calculation ◽  
Bending Moment ◽  
Order Effect ◽  
Longitudinal Distribution ◽  
Ship Motions ◽  
Bending Moments ◽  
Method Of Calculation ◽  
Static Calculation ◽  
Order Of Magnitude ◽  
Experimental Findings

The longitudinal distribution of forces acting on a T2-SE-A1 tanker moving in regular head seas is found by an analysis based on the "strip method" used by Korvin-Kroukovsky in the development of his theory of ship motions, lending moments at the midship section are calculated and compared with bending moments measured during model tests. The theoretical values of bending moments are of the same order of magnitude as those found in the experiments. However, some discrepancies between them appear. These may be due to experimental error as well as to deficiencies in the method of calculation. Certain important facts are brought out by the theoretical calculations:The midship bending moment is virtually a second-order effect dependent on local variations in the longitudinal distribution of the loads.Dynamic bending moments at reasonable speeds are less than those obtained by the conventional static calculation with Smith correction. This confirms experimental findings.

Association Analysis of System Failure in Wide Area Backup Protection System

2015 ◽  
Vol 16 (6) ◽  
pp. 517-523
Author(s):  
Yagang Zhang ◽  
Yi Sun
Keyword(s):  
Association Analysis ◽  
Differential Method ◽  
Protection System ◽  
Wide Area ◽  
Engineering Practice ◽  
System Failure ◽  
Validity And Reliability ◽  
Method Of Calculation ◽  
Backup Protection ◽  
Electrical Quantity

Abstract Wide area backup protection algorithm based on fault component identification is the heart of the whole wide area backup protection system, its validity and reliability is a problem which needs to be first considered in the engineering practice applications of wide area backup protection system. Wide are backup protection algorithm mainly use two kinds of wide area information to realize protection criterion, one is electrical quantity information, such as voltage, current, etc. Another one is protection action and circuit breaker information. The wide area backup protection algorithm based on electrical quantity information is mainly utilizing the significant change of electrical quantity to search fault component, and the primary means include current differential method of wide area multi-measuring points, the comparison method of calculation and measurement, the multiple statistics method. In this paper, a novel and effective association analysis of system failure in wide area backup protection system will be discussed carefully, and the analytical results are successful and reliable.

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