Application of NX Siemens PLM software in educational process in preparing students of engineering branch

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1 Application of NX Siemens PLM software in educational process in preparing students of engineering branch G. M. Sadchikova Citation: AIP Conference Proceedings 1797, (2017); View online: View Table of Contents: Published by the American Institute of Physics Articles you may be interested in The use of applied software for the professional training of students studying humanities AIP Conference Proceedings 1797, (2017); / The use of process approach to base the need of automation of business processes in educational institutions AIP Conference Proceedings 1797, (2017); / The use of the computer training system as the factor of effective formation of information competence of future IT-specialists AIP Conference Proceedings 1797, (2017); / Mathematical modeling of the transition processes in the electric power system AIP Conference Proceedings 1797, (2017); / Methodical and technological aspects of creation of interactive computer learning systems AIP Conference Proceedings 1797, (2017); / Methodology of problem-based learning engineering and technology and of its implementation with modern computer resources AIP Conference Proceedings 1797, (2017); /

2 Application of NX Siemens PLM Software in Educational Process in Preparing Students of Engineering Branch G. M. Sadchikova Balakovo Institute of Engineering and Technology a branch of the National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), ulitsa Chapaeva, 140, Balakovo, Saratovskaya oblast, Russia, sad_gm@mail.ru Abstract. This article discusses the results of the introduction of computer-aided design NX by Siemens Plm Software to the classes of a higher education institution. The necessity of application of modern information technologies in teaching students of engineering profile and selection of a software product is substantiated. The author describes stages of the software module study in relation to some specific courses, considers the features of NX software, which require the creation of standard and unified product databases. The article also gives examples of research carried out by the students with the various software modules. INTRODUCTION The products of modern engineering enterprises are characterized by high complexity and precision. Furthermore, to produce competitive products it is required to provide a short time for design and the introduction of new products as well as the modifications of products already produced. Such a problem cannot be solved without the use of modern software both for design and technological preparation of production and for engineering analysis, i.e. CAD / CAM / CAE systems. The situation in the industry as well as the need to improve the education quality of students requires a corresponding preparation of the graduates of branches and specialties related to mechanical engineering. Since 2007 The Balakovo Engineering Institute of Technology, a branch of The National Research Nuclear University MEPhI (BETI MEPhI), has been training students the profile Product Design & Technological Preparation of Machine-Building Production (DTPMBP) and specialty Technology of Mechanical Engineering (TMS) with the NX computer-aided design (CAD) system developed by Siemens PLM Software. The NX software as well as Catia and ProEngineer programs refers to heavy computer-aided design systems and is characterized by great functionality, high performance and stability. The NX software supports product developing and manufacturing at all stages of the life cycle, from creating 3D models of parts, assemblies and drawings to the creation of the software for the parts production with NC-machines and to shop designing. Besides that, the software uses the graphics core Parasolid (in-house development), which is the standard for many design automated systems of different levels, which enables data exchange between these systems and NX software. Siemens PLM Software provides higher education institutions WITH a fully functional free university license, which is very important for institution budgets and has determined the choice of the software to study at our institute at a large extent.. STAGES OF STUDY NX SOFTWARE Before the NX implementation in the educational process the lecturers of Science of Machine Department have been trained on the basis of the Siemens offices in Moscow and Nizhny Novgorod. The training was conducted by the following modules: Modeling, Assembly and Processing. The lecturers obtained their certificates Information Technologies in Education of the XXI Century (ITE-XXI) AIP Conf. Proc. 1797, ; doi: / Published by AIP Publishing /$

3 according to the results of the training. It should be noted that the training module Modeling a basic course held in the Moscow office was free of charge for university lecturers working with the software was free of charge and a significant discount was made for the rest of the courses. Our students begin studying the NX software in the third year within the framework of Integrated Computer Design & Manufacturing Technologies (CAD / CAM-systems) discipline, which is expected to last for two semesters. In the first semester at review lectures students are familiarized with the existing corresponding CADsystems applied for mechanical engineering, from the simplest systems to the full-featured ones. Then the NX structure, functional capabilities and features of work with the NX software are discussed in detail. At the workshops the software study begins with basic concepts such as interface customization, coordinate system, work with layers, methods of shading, zoom and image preview. An important stage of the software study is to work in Section Sketch. At this stage students develop model sketches based on dimensions, geometrical constraints and other tools of the Section. Then 3D models are developed using the sketches and tools of Section Simulation, at first with ready examples and then according to production drawings. 3D modeling possesses great advantages. 3D systems can simulate the item followed by the creation of its drawings. The model can be studied from any point changing the zoom. It is possible to find errors in the project, as well as to check the item for assemblability that is required for the subsequent manufacture. 3D models are the basis for engineering design, product functionality analysis, strength, durability and load stability. The mass-inertial characteristics, volume and other important physical properties of parts and assemblies are calculated by 3D models as well as the software for NC-machine tools is automatically generated. A 3D model being once developed can be reused many times to create a family of similar objects. It is very important that the visibility at the 3D modeling raises the interest of students to the design process. A good methodological support from the developer should be noted. Books of design preparation sections techno-logical training and engineering analysis are freely available at the website of Siemens. You can also use ready blank files and the way of working with such files is described in the textbooks [1], [2], [3]. During the production practice after the third year students consolidate the knowledge acquired. Of course, students work not only with the NX software and the development of other programs is faster because the designers of CAD system seek to unify the software interface. Many students work with Catia software during their production and undergraduate practice and, in their opinion, the study of NX facilitates the development of Catia. In the second semester of the fourth year students study machining module, in which the program for part turning drilling and milling is written. Students cannot try out the program written on a selected machine without CAD systems because the machine equipment of the Institute is limited. The module machining enables one to develop a program for the CNC machine, view the tool pass and visualize machining on the basis of a 3D model of a part, a tool selected from the tool database or created by the user and with the specific machining strategy. This reveals errors that can be solved at the design stage. The NX software includes an extensive database of machine models and post-processors, which enables one to transfer the finished program to the selected machine. If there is a designed device for part machining we get a full digital machining model with the ability to visualize and optimize. As a part of CAD of technological processes discipline being studied during the second semester of the fourth year, students develop tools for parts securing with the NX Assembly module and make the programs for parts assembled machining on CNC machines in the Assembly module. Traditionally two ways of working with assemblies are distinguished: bottom-up design and top-down design. By using the bottom-up design the parts and subassemblies are created as independent components and position of components previously added or relative to the selected coordinate system. The top-down design means the creation of a top-level assembly and then going down and adding new components and subassemblies. The bottom-up design was applied for device developing by using the interfaces. In this case addition in the assembly of one component happens irrespective of addition of other components. The interface method is the most common and often the most effective for the development of devices and units. This method is especially urgent when it is necessary to perform a kinematic analysis of a structure created and to calculate dimension chains and in cases when a number of standard and imported components are used. The Assembly module provides the creation of assembly models by both top-down and bottom-up designs. The module functional enables one to create, edit and manage the assembly structure making interface between the components and managing flexible deformable components of the assembly (e.g. hoses or some identical hydro cylinders in different position of the stem). The device developed in the Assembly module can be checked on the intersection and its interactive work, also it is possible to perform a kinematic analysis

DATABASES OF STANDARD & STANDARDIZED PARTS When working with NX software it was found out that there is no ready database of standard fasteners which is supplied with the software.

The part database is created by using the built-in access to the spreadsheet Excel on the basis of the reference parts together with the creation of standard size table containing all the parts of

The algorithm for generating a database of standard fasteners is as follows: 1. Developing a prototype part model. 2.

4 DATABASES OF STANDARD & STANDARDIZED PARTS When working with NX software it was found out that there is no ready database of standard fasteners which is supplied with the software. To fill this gap students created a database of fastener 3D models including such parts as washers, screws, bolts, studs, nuts, screws of standard sizes by means of the option Part Family [4]. The part database is created by using the built-in access to the spreadsheet Excel on the basis of the reference parts together with the creation of standard size table containing all the parts of the family. Owing to the option Part Family you can get parts of new models on the base of standardized parts only changing the necessary parameters (in this case, the size) of the unified parts. The algorithm for generating a database of standard fasteners is as follows: 1. Developing a prototype part model. 2. Defining the parameters which are changed during the formation of the family part members. 3. Creating and saving the parameter table in which the parameter values are set for all members of the family. The part parameters are set in EXCEL table by entering the values of these parameters in the corresponding row. Figure 1 shows an example of creation of standard fastener database with the NX software. FIGURE 1. Creation of standard fastener database with the NX software. The option Part family is also used to create the database of device typical element modules in the machine tool. The creation of the device database in NX reduces the time of its designing, that result in decreasing the cost of tools development and consequently the production costs under the manufacturing conditions. The database of device standard elements includes the following parts: A clamp is a device used to secure parts on the machine table during machining. A spring is an elastic element for accumulating and absorbing mechanical energy. A cylindrical pin is designed for a specific orientation of the part blank in the fixture. A rhombic pin is designed for a specific orientation of the part blank. A base is a plate with holes designed for the installation of the device with the part blank in the machine tool. A rib is a part required to increase the rigidity and reliability of the structure

RESULTS OF SOFTWARE IMPLEMENTATION Building 3D Models It should be noted that the students of DTPMBP and TMS specialty have their

One of the tasks during their work at the enterprise is the creation of 3D models of parts according to the drawings.

Within the framework of graduate design the students develop more complex parts which require fairly deep knowledge of the NX

It should be noted that the application of information techniques in the educational process raises the students' interests in the

students try to study a part of the program functionality during additional consultations or by themselves.

there is a free access to the textbooks of all sections of the NX software containing file blanks and examples of completed tasks.

5 RESULTS OF SOFTWARE IMPLEMENTATION Building 3D Models It should be noted that the students of DTPMBP and TMS specialty have their practical training at machinebuilding enterprises where they get acquainted with design and technological production preparation. One of the tasks during their work at the enterprise is the creation of 3D models of parts according to the drawings. At the same time the students can get acquainted with the manufacturing technique of the part and see the part both in the form of the work piece and the machined one. An example of such work piece and a group of parts built on the basis of the part representative is shown in Fig. 2 (a) and (b). Within the framework of graduate design the students develop more complex parts which require fairly deep knowledge of the NX software. It should be noted that the application of information techniques in the educational process raises the students' interests in the study of the discipline, although sometimes they do not have enough knowledge acquired within training time, that is why the students try to study a part of the program functionality during additional consultations or by themselves. Besides that, as it was noted above, a large number of educational information can be found on Siemens PLM Software website where there is a free access to the textbooks of all sections of the NX software containing file blanks and examples of completed tasks. (a) FIGURE 2. (a) Part blank. (b)group of parts (b) Examples of the parts the machining process of which was developed by the students under their research design are given in Fig. 3 (a, b). (a) FIGURE 3. (a) Housing Figure, (b) Crankshaft. (b) Figure 3(a) presents a feature of the model presented the conjugation of sections of different shapes and Fig. 3(b) shows a photorealistic view of the part

Creation of Software for NC-Machines Figure 4(a) shows the result of the formation of the path of tool motion during the part milling the machining process of which was developed as the part of a

It is very convenient when you change the 3D model parameters on which the machining software is formed, the path of tool motion is recalculated automatically.

and etc. can be revealed. In this case the developer monitors the movement of the 3D model of the tool relatively to the part during its machining (Fig. 4(b)).

6 Creation of Software for NC-Machines Figure 4(a) shows the result of the formation of the path of tool motion during the part milling the machining process of which was developed as the part of a research design. It should be noted that the software stores the machining sequence as well as tool changing. It is very convenient when you change the 3D model parameters on which the machining software is formed, the path of tool motion is recalculated automatically. During the verification of the manufacturing process, such problems as overcutting, collision, material contact during the quick-action feed, excessive allowance for machining, unmachined surfaces and etc. can be revealed. In this case the developer monitors the movement of the 3D model of the tool relatively to the part during its machining (Fig. 4(b)). The process can be interrupted at any moment and any correction and addition can be made. Fig. 4(c) shows the verification of the milling of the part Bush placed in a double fixture. (a) (b) (c) FIGURE 4. (a) Path of milling tool movement; (b) Verification of milling process; (c) Part machining in an attachment. Development of Attachments/Devices for Part Machining by NC-Machines The attachment development is a quite time-consuming process. However, the state-of-art CAD systems can reduce the complexity of the design process by adopting standardized elements of attachments and fixtures and updating the tools already developed. At the beginning of NX learning several simple devices (Fig. 5) were

developed, which could help the students understand how to mount and fix an item in the device, how to install the device on a machine, how parts fixed in the device are machined and whether it is

Of course, the drawings are not able to provide such understanding and it is not always possible for a student to observe the device operation in the production process.

When a student assembles the device element-by-element and places a part in it, they can recognize this device not worse than an experienced engineer or master at the factory.

7 developed, which could help the students understand how to mount and fix an item in the device, how to install the device on a machine, how parts fixed in the device are machined and whether it is possible to machine the part with the device design developed. Of course, the drawings are not able to provide such understanding and it is not always possible for a student to observe the device operation in the production process. In this case this is the advantage of modern information technologies used in product design and technological preparation. When a student assembles the device element-by-element and places a part in it, they can recognize this device not worse than an experienced engineer or master at the factory. The visualization of every part and the assembled product facilitate the understanding of the principle of its operation. FIGURE 5. Attachment for milling As far as the students obtain experience in designing with the NX software, the developed devices become more complex and currently along with mechanical devices (Fig. 6(a)) they design devices with hydraulic drive for fixing parts being machined (Fig. 6(b)). (a) FIGURE 6. (a) Device with mechanical fixing for part Body ; (b) Device with automated fixing for part Body. Pre-Graduation Practice and Research Resign During their pre-graduation practice the students get acquainted with the production technology of a selected part, study the route and operating technology, make their proposals for the process modernization, offer more advanced options for making part blanks and machining parts by NC machines. Within the bounds of research design the students develop a three-dimensional model of a part, a program for machining the part by the NC machine, assemble model of a device for fixing the part blank on the machine for machining, design a workshop site in which the part will be made. (b)

When designing the workshop site the students apply a training version of Plant Simulation software, which is freely available on Siemens website.

It should be noted that a student learns the software independently and its application in the graduation design is not required.

8 When designing the workshop site the students apply a training version of Plant Simulation software, which is freely available on Siemens website. The software is used for calculating the machine utilization, which can be optimized. It should be noted that a student learns the software independently and its application in the graduation design is not required. However, some graduates use this software, which confirms the interest of the students in information technology. Independent Work of Students In the curriculum under which the students are taught, more than half of class hours appropriated for the discipline study fall on the independent work of the students. It is conditioned by the fact that in the globalized labor market professional qualifications, understood as a body of knowledge and skills, are not enough to solve the problems arising when a graduate starts working at an actual factory. A future professional should be ready to solve non-standard professional tasks and therefore should have the ability to acquire and develop the necessary professional competence throughout his/her labor activity. A student, who is committed to the professional development and getting an interesting high-paid job after graduation, should be ready for independent knowledge acquisition and its development. The development of 3D models of accessories and other devices based on the items used in the Institute s laboratories as visual aids or existing layouts is proposed as a part of students independent work in the discipline Computer Integrated Design & Manufacturing Technologies (CAD / CAM-System), for which 130 academic hours from 288 ac.h. are given in the bachelor working curriculum of the Profile Design and technological support of machine-building production. The students take apart the items, then measure the individual parts, determine how the item works in dynamics and develop digital models of these items. The example of such an item is shown in Fig. 7(a). A worm reduction gearbox is used as an object of the simulation. The gearbox consists of the following components and standard products: a worm gear, a housing, bearings and fasteners. The students should work as follows: 1. Disassemble the gearbox into individual parts. 2. Measure the parts. 3. Develop a 3D parametric model of individual parts in the module Simulation of the NX software. 4. Develop an assembly module with the appropriate conjugation in the NX module Assembly. 5. Determine the intersections with the help of the Analysis of gaps in the assembly command. 6. Carry the kinematic analysis of moving parts and simulate the principal of the worm gear operation in the NX module Simulation of kinematic mechanisms. A simplified assembly model of the reduction gearbox is shown in Fig. 7(b). (a) FIGURE 7. (a)worm reduction gearbox; (b) Simplified model of worm gear. (b)

Figure 8 shows a worm pair with kinematic linkages developed in the NX module Simulation of kinematic mechanisms. FIGURE 8. Worm pair with kinematic constraints.

9 Figure 8 shows a worm pair with kinematic linkages developed in the NX module Simulation of kinematic mechanisms. FIGURE 8. Worm pair with kinematic constraints. It should be noted that students with a great interest fall into to independent work, the bound to creation of 3D and kinematic models of real items. The graduates of the Machines science Department of the Balakovo Institute of Engineering and Technology are in demand at the enterprises not only in Balakovo but also in different cities of the Volga region e.g. Saratov, Volsk, Samara, Syzran and Nizhny Novgorod and not only for machine building enterprises. Our graduates also work in Moscow, St. Petersburg and in other largest Russian cities. CONCLUSION 1. The necessity of the introduction of state-of-art information technologies in the process of training future engineers is reasoned by the growing need for high-skilled professionals with information competence and skills to work with CAD systems. 2. The demand for graduates of the engineering profiles and specialties and their competitiveness are largely determined by the knowledge of modern software applications for CAD at the stages of design and technological preparation of production. 3. The increased interest of today s young people in everything regarding computers and the application of modern information technologies in the learning processes raises the interest of students in the study of relevant disciplines resulting in the improved assimilation of educational material and students progress. The amount of information that a student can learn at lectures, practical and laboratory classes increases dramatically. 4. The introduction of information technologies in the learning process has the certain difficulties as it is necessary to choose the appropriate program, contact the program developer or the seller to issue a number of documents and to arrange preliminary training of lecturers. Very often the implementation of such programs is supported by the enthusiasm of individual lecturers and the staff of departments. 5. Information technologies enable a student to get more knowledge, to develop intelligence, and creativity and the ability to acquire new knowledge independently, to work with different sources of information, which helps a graduate adapt to a manufacturing process faster and more effectively after graduating from a higher educational institution. 6. It is necessary for developers of CAD systems to take into consideration that students can work in factories and they may take management positions. And they will choose CAD systems using their experience of working with the software using their experience of working with the software from the time when they studied at the institute. That is why it is important to ensure preferences for a higher educational institution both in obtaining a license for the software and the further technical and information support for the work in the software acquired

10 REFERENCES 1. P. A. Vedmid, A. V. Sulinov, Programming of machining in NX CAM (DMK Press, Moscow, 2014). 2. P. A. Vedmid, Fundamentals of NX CAM (DMK Press, Moscow, 2012). 3. I. A. Artamonov, P. S. Goncharov, S. V. Denisichin, D. E. Sotnik, and T. F. Chalitov, NX Advanced Sumulation. A Practical Guide (DMK Press, Moscow, 2014). 4. Yu. V. Danilov, Practical use of NX (DMK Press, Moscow, 2011)

EG - Engineering Graphics

EG - Engineering Graphics Coordinating unit: 205 - ESEIAAT - Terrassa School of Industrial, Aerospace and Audiovisual Engineering Teaching unit: 717 - EGE - Department of Engineering Presentation Academic year: Degree: 2018 BACHELOR'S