Modeling problems in the strength analysis of machine-building structures

1997 ◽  
Vol 33 (6) ◽  
pp. 614-618
Author(s):  
V. N. Skopinskii
Keyword(s):  
Machine Building ◽  
Strength Analysis ◽  
Building Structures

Substantiation of Thin-Walled Structures Parameters Using Nonlinear Models and Method of Response Surface Analysis

2019 ◽  
Vol 44 ◽  
pp. 32-43 ◽  
Author(s):  
Maryna Bondarenko ◽  
Mykola Tkachuk ◽  
Andriy Grabovskiy ◽  
Iryna Hrechka
Keyword(s):  
Response Surface ◽  
Nonlinear Models ◽  
Rational Solution ◽  
Machine Building ◽  
Surface Shape ◽  
Design Solution ◽  
Building Structures ◽  
Design Work ◽  
Global Trends ◽  
Thin Walled

The article deals with the development of approach for providing of structural strength of complicated thin-walled machine-building structures, which operate in the conditions of geometric and physical nonlinearities using design solution validation. The developed approach is based on the use of mathematical model for stress-strain state taking into account geometric and physical nonlinearities and methods of approximation for constructing functions describing the evaluated characteristics of the object under study. The various factors behind the search for design solutions (including characteristics of strength, rigidity, technological and economic factors), are being added into this function. The developed algorithm for rational parameters search, which takes into account the peculiarities of the response surface shape observed in solving applied problems, is applied to them. In this case, the solution is sought over the whole range of parameter changes. Thus, in the search process, global trends of changes in design decisions are taken into account, and not local ones, as in other approaches. This allows obtain a rational solution that is stable to changes in parameters, which are possible in course of design work and production conditions. Investigations are illustrated on the freight rail-car, tractor cabin frame, carrier personnel hull.

scholarly journals АNALYSIS OF THE SENSITIVITY OF DYNAMIC AND STRENGTH FUNCTIONALS OF MULTICOMPONENT MACHINE–BUILDING STRUCTURES

2019 ◽  
Vol 0 (7(1332)) ◽  
pp. 60-65
Author(s):  
Sergej Aleksandrovich Nazarenko ◽  
Svitlana Ivanivna Marusenko ◽  
Olena Ivanivna Zinchenko
Keyword(s):  
Machine Building ◽  
Building Structures

scholarly journals COMPARATIVE ANALYSIS OF COMPUTABLE DYNAMIC MODELS OF PORT CRANES ON THE BASIS OF ONE AND TWO-DIMENSIONAL FINITE ELEMENTS

2019 ◽  
pp. 127-144
Author(s):  
Nikolay Nikitovich Panasenko ◽  
Alexey Vladimirovich Sinelshchikov
Keyword(s):  
Finite Element ◽  
Comparative Analysis ◽  
Finite Elements ◽  
Dynamic Models ◽  
Flexural Rigidity ◽  
Equations Of Motion ◽  
Machine Building ◽  
Quality Analysis ◽  
Forced Oscillations ◽  
Building Structures

The finite element method is widely used in strength calculations of machine-building structures and has a significant list of basic finite elements used to build the discrete finite element computable dynamic models of load-lifting cranes. The article describes static and dynamic characteristics of a computable dynamic model (CDM). CDM is designed to determine stiff features (developing stiffness matrix) and to define the deflected mode of the structures by using different means in structural mechanics, which have been chosen by a designer. Dynamic parameters are determined according to CDM to describe eigen and forced oscillations of crane structures under external action. The quality analysis of CDM of bearing metal structures of bridge cranes built on the basis of bar-shaped open and closed profiles and plate finite elements is based on comparison of the total flexural rigidity of the girders and eigen frequencies and eigenforms of oscillations of their CDM. The general methodology for building equations of motion for crane systems with many (n) degrees of freedom is based on their bar and plate finite elements, the latter are based on Kirchhoff theory of plates. Comparative analysis of the eigenforms of oscillations of the plate and bar CDM of crane with 130/32 t and 33.5m span has been given, the advantages of two types of CDM important for design analysis of strength and seismic resistance in designing bridge cranes are revealed. There has been substantiated the need to develop new methods of calculating finite element models taking into account the dimensional effect. The structures are recommended to regard as unified dimensional systems allowing for different types of non-linearity.

scholarly journals Discrete and Continual Strengthening of Contacting Structural Elements: Conception, Mathematical and Numerical Modeling

2019 ◽  
Vol 18 (3) ◽  
pp. 240-347 ◽  
Author(s):  
N. A. Tkachuk ◽  
S. A. Kravchenko ◽  
V. A. Pylev ◽  
I. V. Parsadanov ◽  
A. V. Grabovsky ◽  
...  
Keyword(s):  
High Efficiency ◽  
Strong Electric Field ◽  
Base Material ◽  
High Strength ◽  
Machine Building ◽  
Structural Basis ◽  
Building Structures ◽  
Wear Properties ◽  
Positive Effects ◽  
Integral Effect

The paper proposes a variant of discrete and continual strengthening of contacting elements of machine-building structures. One of the parts is strengthened discretely, and its counterpart is strengthened continually. The resulting pair combines positive qualities of two different types of strengthening methods. Investigations on stressed-deformed state of the treated fragments provides a basis for conclusion about high efficiency of the proposed combined strengthening method. While applying the method mechanisms of negative feedback between the stages “loading – contact interaction – friction – wear” are involved unlike with conventional versions of strengthening technologies. In this way, positive integral effect results from an application of the developed strengthening technology. This effect is significantly higher than the sum of effects obtained owing to application of every strengthening technology. In this case a favorable distribution of contact pressures between contacting bodies has been ensured. This, in its turn, leads to a decrease in wear that prevents a sharp increase in loads acting between bodies. Thus stabilization of the investigated processes occur. The papers considers stress-strain state of a representative fragment of the investigated system in order to demonstrate positive effects arising from the contact of strengthened bodies. Results of the calculations indicate validity of forecast assumptions. Indeed, the strengthened zones can bear high loads. However, due to high tribo-mechanical properties of the material in the hardened zones, friction and wear in them are much lower than for a base material. Due to this, all positive components of the total effect are formed. This effect is supported by the fact that a counterpart is processed continually. In particular, metals from aluminum-type materials are coated with a thin layer of oxides by forming them in a strong electric field of a special medium. Formed solid phases of oxides serve as a structural basis for formation of surface layers. In combination with discretely strengthened surfaces of counterparts the formed pair acquires high strength, antifriction and anti-wear properties.

scholarly journals Performance assurance of mechanical engineering construction in the existence of cracks

2019 ◽  
Vol 287 ◽  
pp. 02004
Author(s):  
Nikolay Velikanov ◽  
Sergey Koryagin ◽  
Oleg Sharkov
Keyword(s):  
Machine Building ◽  
Radius Of Curvature ◽  
Building Structures ◽  
Brittle Strength ◽  
K Value ◽  
Engineering Construction ◽  
Safe Side ◽  
Strength Uniformity ◽  
Structural Methods ◽  
Further Development

The purpose of this paper is to consider the development of engineering ways of preventing the further development of through cracks in the sheet elements of the complex technical structures. The latest individual approach to the assessment and assurance of performance of structures with cracks, which is to take into account the features of their operation, has been applied in this work. Preference is given to methods that reduce the concentration in the danger zone. Studies have shown that the most appropriate and effective ways to prevent the further development of a through crack are the structural methods and combinations of the structural and technological methods. The effectiveness of these methods was determined on the basis of the strength uniformity approach of structural elements with a crack. The criterion of strength uniformity from the position of fatigue and brittle strength with an error on the safe side is the value of theoretical stress concentration factor [K]. The[K] value was made on the basis of generalization and analysis of cases of crack formation, the results of tests of typical components of hull structures and welded joints. The safe concentration of stresses near the holes of various purposes in the members of the machine-building structures is in the range from 2 to 4. Taking into account the relevant requirements for the ratio of the radius of curvature and the width of the cutout, we obtain 3.5. The value of the criterion К1 is determined by the ratio of the calculated crack length to the diameter of the hole drilled at its ends and the location of the crack.

scholarly journals Experimental Tests of Discrete Strengthened Elements of Machine-Building Structures

2020 ◽  
pp. 559-569
Author(s):  
Andrii Marchenko ◽  
Mykola A. Tkachuk ◽  
Sergiy Kravchenko ◽  
Mykola M. Tkachuk ◽  
Igor Parsadanov
Keyword(s):  
Experimental Tests ◽  
Machine Building ◽  
Building Structures

scholarly journals Calculation of elements of machine-building structures on vibration strength

2021 ◽  
Author(s):  
Andrii Babenko ◽  
Oleg Boronko ◽  
Serhiy Trubachev ◽  
Yaroslav Lavrenko
Keyword(s):  
Large Scale ◽  
Descent Method ◽  
Machine Building ◽  
Coordinate Descent ◽  
Automated System ◽  
Engineering Practice ◽  
Building Structures ◽  
Coordinate Descent Method ◽  
Vibration Strength ◽  
Calculation Algorithms

A method and an automated system for calculating structural elements for vibration strength have been developed. The calculation algorithms are based on a new method of forming Rayleigh-type functionals and minimizing them by the coordinate descent method. The use of the coordinate descent method avoids the problems associated with the formation, storage and operation of global matrices of stiffness and mass. This makes it possible to solve large-scale problems using only the operational memory of the PC. The developed approach allows to solve problems on own and forced fluctuations. The software is formed on a modular basis, which allows you to improve and expand this package of applications. The software has been tested on a large number of test and application tasks. The proposed calculation method and the developed automated system were implemented in engineering practice.

scholarly journals ANALISIS KEKUATAN BANGUNAN TERHADAP GAYA GEMPA DENGAN METODE PUSHOVER STUDI KASUS GEDUNG ASRAMA PUSDIKLAT PPATK, DEPOK

2019 ◽  
Vol 3 (2) ◽  
pp. 99-106
Author(s):  
Tatya Putri Utami ◽  
Niken Warastuti
Keyword(s):  
Development Planning ◽  
Strength Analysis ◽  
Building Structures ◽  
Safety Level ◽  
Tectonic Plates ◽  
Linear Behavior ◽  
Earthquake Force ◽  
Boarding House ◽  
Earthquake Load ◽  
Maximum Earthquake

Indonesia is an archipelago country located at a meeting of three tectonic plates so that Indonesia has the potential to experience an earthquake. As a result of the earthquake many buildings are damaged building structures. When an earthquake happens, the building is expected to be able to accept a certain level of earthquake force without significant damage to the structure or if the collapsing structures must be able to give non-linear behavior in the postelasticconditions so that the building's safety level against earthquake and safety of the occupants is more secure. The Pusdiklat PPATK boarding house, Depok is a building which in its development planning is expected to be able to accept the earthquake force and behave non-linearly. But this dormitory building does not yet have data on building resistance to earthquake forces. Therefore it is necessary to analyze this building by using one method of building strength analysis to earthquake forces that is pushover method. This analysis is done using SAP2000 program. The conclusion of the analysis shows that the greater the force (base force) given the greater the displacement that occurs in the building. The maximum earthquake load that the building can accept is 730,383 kN. Based on the ATC-40 performance limit the building is at the level of IO, indicating that the building is safe to use during an earthquake.

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