APPLICATION OF APM WINMACHINE SOFTWARE FOR DESIGN AND CALCULATIONS IN MECHANICAL ENGINEERING

Dep. «Building Mechanics», Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan, Lazaryan St. 2, Dnіpropetrovsk, Ukraine, 40910, tel. +38 (067) 810 51 65, e-mail nlorhen@i.ua, ORCID 0000-0002-7038-3006 EDSD MBCSS, Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan, Lazaryan St. 2, Dnіpropetrovsk, Ukraine, 49010, tel. +38 (050) 214 14 19, e-mail angela_shvets@ua.fm, ORCID 0000-0002-8469-3902


Introduction
Industrial production is one of the main parts of the national economy of any country that provides vital interests, economic security, social and cultural level of the population, determines the technical and economic potential [15,18].
One of the most complicated and most critical industries is machine building.Its share in total industrial production and the size of export of engineering products are the indicators that most accurately determine the general level of economic development.In the modern context mechanical engineering plays an important role in accelerating scientific and technological progress because it largely determines its general directions and is the foundation of the economy, plays a crucial role in creating and updating its material and technical base.
Mechanical engineering is the leading sector, whose share by value is about 1/3 of the world industrial production (Fig. 1, a) [15].Inter-branch economic complex of Ukraine integrates the system if research, design and technological organizations, enterprises, whose products have common economic purpose, production and operational similarity.Location of enterprises of various engineering branches depends on such factors as the level of science; availability of appropriate human resources, raw materials, consumer (Fig. 1b).[18].

Purpose
Nowadays, on the days of rapid development of computer information technology, no sector of the national economy can do without modern software systems to perform complex engineering calculations and to make the right decisions.To conduct the research at all stages of design, development, operation, residual operation life determination, namely, preliminary study, action principle choice, design of draft and technical projects, their optimization, preparation of design documentation and control information for automated production, comprehensive engineering analysis, it is required to use the latest computer technologies.Their use can not only present data and information in some way, but also gives the opportunity to effectively and directly interact with the information object that is created or demonstrated.These and many other problems are solved with the help of modern information technologies that confirms the relevance of their application.
Topicality.In today's world the computer information technology is rapidly penetrating into all spheres of activity -today the successful are only those sectors of the national economy, only those educational institutions or commercial companies that own the latest computer technologies.Over the past decade they have undergone such a global expansion, that it is hard to imagine human life and production activities without them.
At this stage you can easily give examples of the use of information technologies in all areas: from education to management.Significant progress is achieved in the field of education due to introduction of appropriate computer technology that can make the knowledge-gathering process available, remote, flexible, individual [13].That is also true of mechanical engineering, including the transport one (Fig. 2), as the complexity of the engineering calculations and making the right decisions requires increasing use of advanced computer systems and technologies [1,7].Their use can not only present data and information in some way, but also gives the opportunity to effectively and directly interact with the information object that is created or demonstrated.These and many other problems are solved with the help of modern information technologies that confirms the relevance of their application.Software packages for various purposes skilfully use modern computer technology (mathematical modelling, knowledge and data bases, computer networks, expert systems and decisionmaking systems, multimedia information technology, information resources of the Internet) at all stages of design, development, exploitation to determine the residual operation life, namely: preliminary study, action principle choice, design of draft and technical projects, their optimization, preparation of design documentation and control information for automated production, comprehensive engineering analysis, etc. [14, 23 -25].

Methodology
To perform engineering calculations associated with the analysis of the strength of machines, mechanisms, constructions one uses both analytical and numerical methods in practice [4,6,19,22].
The most commonly used method for analysis of stresses and deformations is Finite Element Method (FEM) [2,11,17,21].It was first elaborated in the 50 years of the twentieth century to solve the problems of strength of materials.It is known that the strength of materials is the science of engineering calculation methods of machine elements, mechanisms and structures for strength, rigidity, stability and belongs to fundamental disciplines of general engineering training of specialists with higher technical education.This is the first discipline that establishes a link between fundamental scientific disciplines (physics, mathematics, theoretical mechanics) and applied problems and methods for their solution, resulting in the design of machines, building structures [8].
During the operation of machines and structures their elements are exposed to different forces -loads.To ensure the normal operation the structure must meet the required conditions of strength, rigidity and stability: Strength is the ability of structure elements to withstand some load without destruction; Rigidity is the ability of structure elements to resist to deformation caused by external load; herewith the deformation should not exceed the permissible ones; Stability is the ability of structure elements to maintain a certain original shape of the elastic equilibrium.
The main purpose of strength of materials is to provide structural strength.It occurs in the form of direct and inverse problem: the direct problem (projecting calculation) is to find reliable (in terms of strength) dimensions of the machine or structure elements, so that they could withstand a set load over the required period of time at the lowest cost; the inverse problem (checking calculation) is to check whether the element of already existing mechanism or structure meets the strength requirements in case of change of a set load, or it needs replacing or strengthening [8].
Thanks to scientists, since 1970, FEM has become increasingly popular among engineers of all specialties; at that time the first software FEM systems were developed.Now it is the main method of computational mechanics, which forms the basis of most modern software systems designed to perform engineering tasks in various fields [2,11,17,21].
Thus, quality improvement of the mechanical equipment and structures must be connected primarily to reduction of their weight and cost, increased reliability and improvement of a number of other characteristics.Currently, the topical problem is combination of two mutually exclusive tendencies in the design: material savings on the one hand, and providing the necessary strength characteristics of structures on the other hand.
This can be achieved through the use of computer technology.Today it is impossible to create high-quality, reliable and competitive equipment without thorough engineering analysis of projected objects using modern software and making appropriate design decisions based on it.The engineering analysis means primarily the designer's study of stress-strain state (SSS) of designed object models, obtaining their dynamic and stability characteristics at constant and variable modes of external load.Assessment of SSS requires the knowledge about distribution of stresses in the elements of designed machines and structures, values of individual point displacement both due to static nature of the external load, and in terms of the loads that vary over time.
Currently, due to the active implementation in engineering practice of computer technology, the most efficient approximate method for solving this class of applied problems in mechanics is the finite element method (FEM) [5,10,20].
FEM key idea is as follows: the solid medium (design model) is replaced with the discrete one by splitting it into finite elements (FE).The behaviour of each medium is described by a separate set of functions that represent the stress and displacement.Finite elements are connected with nodes; FE interaction is realised only through nodes.Located in a certain way, depending on object design, and secured in accordance with the boundary conditions, finite elements can adequately describe the diversity of models of parts and structures [9].
The end element can be imposed with external loads (concentrated and distributed forces and moments), which are applied to the element nodes and are called nodal loads.
When calculating using FEM first the displacements of model nodes are determined.The values of element internal forces are proportional to displacements of the element nodes.Proportionality factor is square matrix of element rigidity, whose number of lines equals to the number of degrees of element freedom (in general, this is the product of the number of degrees of node freedom by the number of element nodes).All other parameters of the final element, such as internal force, stress, displacement field, etc. are calculated on the basis of its nodal displacements.
Finite element method allows almost full automation of calculation of mechanical systems, but usually requires much more computing operations compared with the classical methods of mechanics.The current level of computing development opens up opportunities for the introduction of FEM in engineering practice [9].
FEM is implemented in many famous and widespread software products, providing strength calculation of models of machines, mechanisms and structures.
The complete finite-element analysis requires: − Choosing the type of finite element (for the entire model or its individual parts), that will help adequately model the real structure; − Building the model of a designed object in three dimensions; − Visualizing the results and interpreting them correctly to take the right design decisions.

Findings
In modern conditions to improve efficiency, achieve the highest quality and feasibility of results, among many of today's software packages, APM WinMachine came into widespread use.This is knowledge-intensive software, created on the basis of modern engineering methods of design, numerical methods of mechanics, mathematics and modelling, which combines the experience of previous generations of designers, mechanical engineers and other professionals with the capabilities of computer technology, to the utmost adjusted for work on design and construction of facilities of engineering and construction industries [1,9].
APM WinMachine software package allows the user to create three-dimensional models of random machines, mechanisms and structures (Fig. 3).Models consist of a rod, shell and solid elements; constructive models of shell and solid types can be imported from any third-party dimensional image editors, using a standard interchange format.− АРМ Graph -flat drawing and graphics editor for execution of design documentation, which has convenient features of parametric geometry task (Fig. 4) [12,16]; − АРМ Studio -module for creating threedimensional surface and solid models with built-in generator for splitting into finite elements (Fig. 5 a,  b) [1,9]; − АРМ Mechanical Data -database of standard parts and components, reference data for general engineering (Fig. 5,); − АРМ Matcrial Data -module for storage and edit of material parameters; − АРМ Construction Data -database of graphics on standard parts and elements of building structures (Fig. 5, g); − АРМ Technology Data -database of standard information data for process design; − АРМ Base -module for creating and editing databases; − АРМ Воок -electronic textbook «Fundamentals of Machine Design», which sets out the basic calculation methods implemented in ARM WinMachine System; − АРМ Веаm -module for calculation and design of beam construction elements; − АРМ Structure3D -module for calculation and design of random structures, consisting of plate (Fig. 6), rod (Fig. 6 B), volume (Fig. 6) elements and their random combinations due to finite element method [1,9].ARM Structure3D module allows calculating the stress-strain state of structures in static mode, performing calculations for resistance and determination of natural frequencies [1,9], analysing the behaviour of structures at random dynamic loads (Fig. 2, 7) [12]; − АРМ Joint -module for calculation and design of joints of machine parts and structural elements, which allows complex calculations of all types of threaded, welded, riveted joints and connections of rotation details; − АРМ Trans -module for design of transmitting rotation intended to calculate all kinds of gears, as well as worm, belt and chain gear drives, to generate drawings of the gear elements in automatic mode; − АРМ Shaft -module for calculation, analysis and design of shafts and axles; − АРМ Bear -module for calculation of imperfect rolling bearings, allowing a comprehensive analysis of rolling-contact bearings of all known types; − АРМ Plain -module for calculation and analysis of radial and thrust bearings operating under conditions of fluid and semi-fluid friction; − АРМ Drive -module for calculation and design of random structure drive, planetary and wave gears.It allows complex calculation of kinematic characteristics and design of drive as a whole and its individual elements with automatic generation of drawings of parts and assemblies including the body; − АРМ Spring -module for calculation and design of springs and other spring-elastic elements of machines (Fig. 8).− АРМ Technology -module for process design.
APM WinMachine software is flexible, reliable means of design and analysis; runs on most popular operating systems of computers -from PC to workstations and supercomputers.Despite the fact that APM WinMachine program has a variety of sophisticated options, its organizational structure and user «friendly» graphical interface makes learning and application of the program very convenient.At the same time the program is completed with documentation that enables to deal with the order of implementation of complex works online.The system «menu» includes «intuitive» features, helping the user to control the program effectually.Output data can be entered using the manipulator «mouse», keyboard or by combin-ing these two options [1,9].
The easiest communication way with APM WinMachine package is the use of menu system, called the user graphical interface (Fig. 9 a).
In all versions of APM WinMachine software package the on-screen menu (Fig. 9, a) includes windows, among which the key ones are as follows [1,9]: 1. Utility Menu -contains service functions used during the entire session on APM Win-Machine software, such as file and image management and settings; this «menu» also provides the program exit.
2. Input Window -allows direct entry of embedded commands.
3. Standard Toolbar -contains buttons for frequently used software commands.
5. Graphic Output Window -display of the main relevant information on current work (Fig. 9, c).
6. Quick Access Toolbar -located below the graphic output window, helps perform online operations.− The static calculation results: structure node displacements (linear and angular); load at the ends of rods, at the nodes of plates and volume elements; epures of force factors for the whole structure; tensions existing in rods, plates and volume elements; stress distribution in random section of the rod; design parameters specific to a single beam, such as bending moments, torsion, lateral and axial force, angles of bending, twisting, deformation and strain along the beam length.All these options are in the form of graphs displayed in the coordinate system of the rod; reactions (forces and moments) acting in bearing supports; structure weight.
− Nodal displacement and load at the ends of rods, at the nodes of plates and volume elements are displayed in the form of table.
− The results of nonlinear calculation are the same parameters as for linear static calculation.
− The result of the strain calculation are the same options as for the static calculation, plus the critical buckling load parameter of the 2nd kind and the buckling mode.
− The result of calculation of the natural frequencies include: a few first frequencies of the structure free oscillations; corresponding forms of free oscillations.
− Calculation results for structure forced oscillations are as follows: structure node displacements; stresses existing in rods, plates and volume elements; reaction in the bearing supports; free frequencies and free forms of oscillations.Analysis of results.APM WinMachine system has a wide range of options for displaying the results.Such calculation results as stress, displacement, force, safety factor, etc. in rods, plates and volume elements can be displayed as a chart of results [1,3,7,12,16].Chart of results is a threedimensional structure, painted in colours in accordance with the values of the selected component of the results on the surface.Colour charts for distribution of equivalent stresses (Fig. 2 b, 4 a, 7 a, 10 b, 11 b) and displacement (Fig. 2 c, 7 b, 10 c, 11 c) internal efforts, safety factor and others allow accurate and quick identification of the most dangerous places in the structure.The program also provides an opportunity to «look» inside the elements and see the resulting distribution of internal force factors.For more complete presentation of results the user has an opportunity to build epures of various force factors on the structure 3D-model, to display reactions in support points, to evaluate the general parameters such as weight, maximum stress, displacement, to produce a summary table of output by metal structure elements.

Originality and practical value
Compared with other software systems, APM WinMachine popularity is explained by easy mastering of the system, quick implementation both in training and in production process [1,3,7,12,16], due to the fact that there is: − the largest number of nodes; − user-friendly interface of all system modules; − wider range of operations within both each module and the entire software system as a whole; − system building based on existing national standards, regulations and principles of design; − possibility of calculations simultaneously in several modules, which speeds up the work process, reduces the risk of erroneous data entry.
In addition, organizational structure, «friendly» graphical interface and accessible language make learning and use of the program very convenient.These and other factors actually reduce the time for project implementation, emphasize the relevance and the practical importance of WinMachine software system, which is appreciated by its users.
The paper considered the aspects, which are unexplored at present, associated with the current state and prospects of development of industrial production, the use of software package for design and calculations in the mechanical industry.The result of the work is the justification of software application for solving problems that are aimed at using research findings for various practical tasks leading to development of new equipment, machinery, mechanisms, etc. to obtain a direct economic benefit in specific fields of mechanical engineering.

Conclusions
The end product of mechanical engineering is machinery, equipment, appliances, instruments and services for all industries without exception.To conduct the whole complex of calculations both for separate kit parts, assemblies, mechanisms and for finished products of kit parts, among many of today's software packages, APM WinMachine came into widespread use.Its use for performance and design of machine parts and various types of their joints and for strength analysis of structures is justified; it actually reduces the problem solution time.
This will allow producing the equipment up to the best analogues, optimal in price, power consumption, etc., and as a result, competitive at the world market.

Fig. 1 .
Fig. 1.State of development geography of: a − mechanical engineering and metalworking of the world; b − engineering industries of Ukraine

аFig. 2 .
Fig. 2. Multiple-unit car body: а − calculation model; b − chart of the stress-strain state; с − chart of the total linear displacement distribution; d − chart of the frequency of free oscillations

Fig. 3 .
Fig. 3. Examples of creation of: a − solid models; b − model of sports complex bearing structure

Fig. 7 .Fig. 8 .
Fig. 7. Charts of metal structure calculation results: a − distribution of equivalent stresses of tower crane; b − distribution of tower crane displacements; c − buckling mode and chart of frequencies of container gantry crane free oscillation

Fig. 9 .
Fig. 9. General view of: a − menu system; b − toolbar «View filters»; c − dialog window showing displacement and load in nodes Thus, APM WinMachine software package helps get the results (Fig. 10, 11), the main of which are as follows [3]:− The static calculation results: structure node displacements (linear and angular); load at the ends of rods, at the nodes of plates and volume elements; epures of force factors for the whole structure; tensions existing in rods, plates and volume elements; stress distribution in random section of the rod; design parameters specific to a single beam, such as bending moments, torsion, lateral and axial force, angles of bending, twisting, deformation and strain along the beam length.All these options are in the form of graphs displayed in the coordinate system of the rod; reactions (forces and moments) acting in bearing supports; structure weight.

Fig. 10 .Fig. 11 .
Fig. 10.Example of bus carcass calculation: a − general view of calculation model, b − chart of equivalent stress distribution; c − chart of displacement distribution