CAD Software Package Research Articles

Design Features of a Removable Module for Securing Containers in Gondola Cars

Purpose. The main purpose of the study is to highlight the design features of the design of a removable module for fastening containers in gondola cars. Methodology. For the safe transportation of containers in gondola cars, it is proposed to use a removable module. This module operates on the principle of an intermediate adapter between the container and the open wagon body. The choice of the profiles of the beams of the frame of the removable module was made according to the moments of resistance of their components. To do this, the core system of the removable module frame was constructed and calculated using the Lira CAD software package. According to the maximum bending moment acting in the module frame due to the moment of resistance and the known permissible stresses, the profile of the frame beams was selected. Taking into account the selected profile of the frame, its spatial model was built and strength calculations were performed. The finite element method implemented in SolidWorks Simulation was used for strength calculations. The calculation was carried out for two loading schemes of the removable module: the effect of a vertical load and the effect of vertical and longitudinal loads. Findings. Based on the calculation, the profile of the removable module was selected according to the determined value of the resistance moment - a square pipe with a height and width of 300 mm and a wall thickness of 5 mm. The results of the strength calculations of the removable module showed that for the case of its perception of a vertical load, the maximum stresses are 112.5 MPa. The maximum displacements occur in the upper parts of the superstructures and are about 1 mm. For the case of the vertical and longitudinal loads perceived by the removable module, the maximum stresses in its structure amounted to 287.6 MPa. The maximum displacements occurred in the end superstructure located on the side of the load applied to the removable module. These displacements amounted to 2.16 mm. Thus, the strength of the removable module for the considered loading schemes is ensured. Originality. A scientific approach to the design of a removable module for securing containers in gondola carsis proposed. Practical value. The research will contribute to the creation of recommendations for the design of modular-type vehicle structures, as well as to improving the efficiency of railway transport operation.

Free2CAD

CAD modeling, despite being the industry-standard, remains restricted to usage by skilled practitioners due to two key barriers. First, the user must be able to mentally parse a final shape into a valid sequence of supported CAD commands; and second, the user must be sufficiently conversant with CAD software packages to be able to execute the corresponding CAD commands. As a step towards addressing both these challenges, we present Free2CAD wherein the user can simply sketch the final shape and our system parses the input strokes into a sequence of commands expressed in a simplified CAD language. When executed, these commands reproduce the sketched object. Technically, we cast sketch-based CAD modeling as a sequence-to-sequence translation problem, for which we leverage the powerful Transformers neural network architecture. Given the sequence of pen strokes as input, we introduce the new task of grouping strokes that correspond to individual CAD operations. We combine stroke grouping with geometric fitting of the operation parameters, such that intermediate groups are geometrically corrected before being reused, as context, for subsequent steps in the sequence inference. Although trained on synthetically-generated data, we demonstrate that Free2CAD generalizes to sketches created from real-world CAD models as well as to sketches drawn by novice users. Code and data are at https://github.com/Enigma-li/Free2CAD.

Systematic Development of a Powder Deposition System for an Open Selective Laser Sintering Machine Using Analytic Hierarchy Process

This work reports on the design and manufacture of an efficient system for powder deposition into layers in an open Selective Laser Sintering machine. The system comprises mainly two subsystems, i.e., one that deposits a dose of powder onto the worktable and another that levels the powder upon its deposition. The design was conducted in two phases, namely conceptualization of the system and its detailed design. The conceptualization phase exploited the Analytic Hierarchy Process to evaluate alternative mechanical systems and determine the most suitable one. This was subsequently detail-designed using a CAD software package and then followed by selection of the necessary electronics for imparting and controlling motion of the individual mechanisms comprising the system. As regards manufacturing, custom designed components were obtained by CNC machining and the entire mechanism was assembled on an open Selective Laser Sintering machine. Functionality testing of the system was performed with satisfactory results.

A parameterized unit cell model for 3D braided composites considering transverse braiding angle variation

In this paper, a parameterized unit cell model for 3D braided composites considering transverse braiding angle variation is proposed, to assist the mechanical characterization of such materials. According to the geometric characteristics of 3D braided composites, a method for automatically generating textile geometries based on practical braiding parameters, including the main braiding angle, the transverse braiding angle, and the fiber volume fraction, is established and implemented in a CAD software package. In this model, the addition of transverse braiding angle educes a more flexible control of fiber volume fraction distribution, and with the combination of control parameters according to the actual fiber distribution needs of users, it can suggest the appropriate parameters for the unit cell. The generated unit cell models are used in finite element analysis and the results are validated against experiments for a number of 3D braided composites in terms of fiber volume fraction and elastic constants, and good agreement is observed. Based on the parameterized unit cell model, the effects of main braiding parameters on the elastic properties of 3D braided composites are discussed.

Generation of Computational 3D Models of Human Bones Based on STL Data and CAD Software Packages

This paper presents three methods of converting complex 3D models of STL type into solid models. For converting the STL models, specific approximation functions from CATIA and Creo Parametric software were used as well as 3D solid modeling methods that used sketches drawn for sections of the specific analyzed model. This conversion is required to get a solid 3D model that can be used for finite element analysis and to be processed using Boolean functions in specific CAD programs. This paper also presents a study of the effectiveness of FEA in respect to the time required for the analysis of each converted model. The analyzed STL files contain data obtained by computer tomography and are the 3D models of the human orthopedic system: the left zygomatic bone and upper part of the right femur. The presented conversion methods can be used by design engineers both in medical applications (where the complexity of forms is well known) for the design of implants and for industrial applications for reverse engineering.

Comparative analysis of CAD software packages for engineering design

This work is focused on the comparison of two software packages Solidworks and Inventor. The following two software packages are well known for their ability to design and they share a leading position in the market. A comparison of the functionality of the two software packages will be made. The difference will be outlined on the divorce tools they have. The market share of CAD software packages will also be briefly outlined. Both software packages will then be compared for how easy they are to use for customers. Lastly, the availabilities of the following software will be discussed.

Optimizacija nosača primenom CAD softvera i biološki inspirisanih algoritama

This paper presents a comparative analysis of the application of biologically inspired algorithms and methodologies in CAD software packages, for determining the optimal profile values in carriers with two independent variables. As an example of a biologically inspired algorithm to solve this optimization problem, the scroll algorithm was applied, while the SolidWorks software package was used as an example of CAD.

О возможности получения суперсверхкритических параметров пара на АЭС с реакторами на быстрых нейтронах с использованием неядерного перегрева пара

The objective of this paper is the determination of the most efficient variant of thermal scheme modification of NPP with BN-1200 reactor from the standpoint of thermodynamic. To solve the problems of NPP thermal scheme modeling the authors have used CAD software package United Cycle, which is designed to solve problems, determine the optimal structure and equipment components of the thermo-energetic facility, and calculate steady-state operation modes. The results have shown that implementation in BN-1200 reactor thermal scheme of steam compression up to 30 MPa and its further intermediate non-nuclear (firing) superheating after high-pressure cylinder the unit`s electrical capacity has increased by 50% and net efficiency increased by 5% which leads to the substantial increase of cycle`s thermodynamic effectiveness.

Experimental Studies on the Stress-Strain State under Drawing Aluminum–Copper Bimetal Parts Rectangular in Plan

The stress-strain state has been studied for a flange of a semiproduct made of an aluminum–copper bimetal under drawing boxes rectangular in plan. These studies are carried out using a grid method, assuming that the material is isotropic and incompressible; the deformation within each cell is uniform; the deformation occurs monotonically; and the stressed state is plane and the deformed state is bulk, but the elastic deformations are negligible. In order to minimize the measurement errors of coordinate grids and reduce the time required for processing information, a CAD software package is used for simulation The billets are rectangles with explosion-welded A4 aluminum and a M4 copper layers subjected to preliminary heat treatment before the operation of drawing. The rectangular billets have been successively drawn to a height of 10 mm; after drawing, the grid and the thickness of the sample under study are measured. The samples of billets have been photographed at an identical focal length and loaded into the application program. In the program, coordinate points are applied to the grid nodes to measure the distances and coordinates of these points before and after deformation. The measurement results show that the greatest deformation is experienced by the corner zones of the billet, where the compressive stresses exhibit an increase from the angle bisector to the walls. These stresses lead to bimetallic billet delamination, as well as to occurring corrugations throughout the copper layer. The drawing is performed for 20 billets and, in each case, the corrugation on the flange surface is observed. Varying the clamping pressure in the range from 0.25 to 0.5 MPa does not lead to any positive results. The end part of the box flange experiences the greatest strain rate, whereas, when approaching the matrix hole, the strain rate exhibits a 20% decrease. The action of angular shear stresses leads to transition-zone discontinuity, which is characterized by the presence of an intermetallic layer having reduced plastic properties.

The civil structures bearing capacity assessment for 150 m high reinforced concrete ventilation pipe based on the field and numerical surveys

In the paper the results of the building structures bearing capacity assessment are presented for a reinforced concrete ventilation pipe with a height of 150 m under seismic effects and tornado loads, taking into account the results of full-scale dynamic and instrumental building structures surveys, based on the linear and nonlinear spatial design models numerical studies.
 This goal was achieved by solving the following tasks:
 
 the vibrodynamic surveys execution;
 the concrete structures strength determination by an ultrasonic method;
 development of linear and nonlinear spatial design models of the pipe;
 the calculations of class F3 tornado effects and intensities 6 (MDE) and 7 (above MDE) seismic impacts.
 
 Based on the results of vibrodynamic surveys, the actual dynamic parameters of the ventilation pipe structures were determined (vibration modes, prevailing periods and frequencies during principal modes vibrations). Based on the results of structures instrumental studies by ultrasonic method, the actual characteristics of concrete structures strength are determined. The obtained field data were used in the development of the facility spatial design models.
 To determine the bearing capacity of structures, the models calculations were performed using the LIRA CAD software package, which is a computer system for structural analysis and design.
 The calculations were performed for the class F3 tornado loads, as well as the intensities 6 and 7 seismic effects determined by the spectral method. Additionally, the bearing capacity of facility reinforced concrete structures was assessed under extreme loads (intensity 7 seismic impacts and class F3 tornado) taking into account the concrete and reinforcement plastic properties. The structures non-linear static analysis (Pushover analysis) applied in the standards of Ukraine, the European Union, the USA and other countries for the assessment of the operating structures seismic resistance was used.
 Based on the results of the research, the reinforced concrete ventilation pipe structures stress-strain state parameters under the considered seismic and tornado loads were obtained and the recommendations were prepared to reduce the possible consequences of an intensity 7 earthquake and a class F3 tornado.

The civil structures bearing capacity assessment for 150 m high reinforced concrete ventilation pipe based on the field and numerical surveys

In the paper the results of the building structures bearing capacity assessment are presented for a reinforced concrete ventilation pipe with a height of 150 m under seismic effects and tornado loads, taking into account the results of full-scale dynamic and instrumental building structures surveys, based on the linear and nonlinear spatial design models numerical studies.
 This goal was achieved by solving the following tasks:
 
 the vibrodynamic surveys execution;
 the concrete structures strength determination by an ultrasonic method;
 development of linear and nonlinear spatial design models of the pipe;
 the calculations of class F3 tornado effects and intensities 6 (MDE) and 7 (above MDE) seismic impacts.
 
 Based on the results of vibrodynamic surveys, the actual dynamic parameters of the ventilation pipe structures were determined (vibration modes, prevailing periods and frequencies during principal modes vibrations). Based on the results of structures instrumental studies by ultrasonic method, the actual characteristics of concrete structures strength are determined. The obtained field data were used in the development of the facility spatial design models.
 To determine the bearing capacity of structures, the models calculations were performed using the LIRA CAD software package, which is a computer system for structural analysis and design.
 The calculations were performed for the class F3 tornado loads, as well as the intensities 6 and 7 seismic effects determined by the spectral method. Additionally, the bearing capacity of facility reinforced concrete structures was assessed under extreme loads (intensity 7 seismic impacts and class F3 tornado) taking into account the concrete and reinforcement plastic properties. The structures non-linear static analysis (Pushover analysis) applied in the standards of Ukraine, the European Union, the USA and other countries for the assessment of the operating structures seismic resistance was used.
 Based on the results of the research, the reinforced concrete ventilation pipe structures stress-strain state parameters under the considered seismic and tornado loads were obtained and the recommendations were prepared to reduce the possible consequences of an intensity 7 earthquake and a class F3 tornado.

Designing and manufacturing of a customized instrumentation for measuring of granular materials mechanical properties by utilizing 3D printing technology

The use of additive technologies allows increasing the availability of scientific equipment in educational centres. The research is dedicated to designing, assembling and testing a laboratory device for measuring the mechanical moduli of granular media. The mechanics of a granular media depend on both the mechanical parameters of individual granules such as particle size, elastic moduli, friction and macro-parameters of the granular media, such as internal structure or humidity. The laboratory device was designed in CAD software package and printed on the 3D printer DF-Print 3.5 using ABS plastic. Comparing to the other similar devices, the advantage of the one we are developing consists in the quick and cheap replicating of its parts on any available 3D printer. The device was tested for different materials, the available range of measuring data and applied loads were determined.

ЧИСЛЕННОЕ ИССЛЕДОВАНИЕ РАБОТЫ ЗАМКОВОГО СОЕДИНЕНИЯ СТЕНОВЫХ ПАНЕЛЕЙ НА РАСТЯЖЕНИЕ ДО ОБРАЗОВАНИЯ ТРЕЩИН

A large-panel design scheme includes floor elements, wall panel elements, and joints between them. The rigidity and strength characteristics in tension, compression and shearare required to be knownfor correct modeling of large-panel buildings. Due to the lack of universal formulas in the normative and reference literature for determining the strength and rigidity of various types of joints, it is necessary to conduct additional research. In 2014 a new type of vertical monolithic joint for large-panel buildings was developed: the fastener joint of wall panels, which has significant strength and rigidity. The fastener includes acheck clamp, which connects the loop outlets on panel ends and the steel plate, which connects the ends of the clamp. It isnecessary to correctly evaluate the strength and rigidity of the joint for its fully- functional application. The experimental research on the joint in tension discovered its bilinear force-deformation relationship (with great rigidity before cracking, and with marginal one after). To analyze the large-panel buildings under the influence of the main operational loads, it is enough to model the joint’s work on the first stage (before cracking). The aim of the research is to study the fastener joint in tension before cracking. The paper compares the results of numerical modeling with the sample testing results, and determines the rigidity and cracking load for joints with other values of the grouting concrete strength and the diameters of the loop outlets. The research was carried out using flat finite-element model in the Lira-SAPR CAD software package. The results of calculation of the joint model are generally consistent with the results of samples testing. In addition, the rigidity and cracking load were determined for joints with various parameters (concrete strength and loop outlet diameter). The results of the study can be usedfor designing large-panel buildings with this type of joint.

Saint-Venant principle for kinematic boundary conditions

A variant of the extended formulation of the Saint-Venant principle is formulated, including its generalization to kinematic parameters. Using the LIRA CAD software package, a numerical experiment is carried out, during which the zones of tangential stress disturbances in the support zone of a rigidly clamped I-beam under various kinematic boundary conditions are determined.

A GIS-BASED AUTOMATED ARCHITECTURAL SPATIAL ANALYSIS AND REPRESENTATION IN THE CONCEPTUAL DESIGN PHASE

This paper introduces an automated workflow using GIS model-builder that enhance the traditional conceptual design process using freehand sketching and CAD software packages and using other software packages for area calculations and visual presentation. Repeating the process of functional evaluation after receiving feedbacks from the clients is one of the main disadvantages of the traditional method, and could consume more time to reproduce calculation sheets and the graphical illustrations.Accordingly, there is an obvious demand to save time and money and to enhance this process. However, using a third-party application could affect that process positively by providing an automated tool that generates a real-time calculation and produces automated graphical studies and colored illustrations.Five steps should be performed to run the automated workflow using GIS model-builder. The original CAD file should be prepared before connecting to GIS then the CAD data sets will be extracted automatically to GIS geodatabase in a predetermined working folder, then sequential geoprocessing tools are run, starting with creating the new feature classes, and finally, the auto generated calculation sheets and colored studies and architectural plans come out.

Analyzing the potential of Virtual Reality for engineering design review

Abstract Virtual Reality (VR) technology still needs to evolve, but as the pace of innovations accelerates, systems allow for more novel modes of visualization and interaction to support engineering design reviews. Currently, the classic design review process is often performed on a PC with the support of CAD software packages. However, CAD on a screen cannot always meet all the requirements in regard to the functional and ergonomic validations of complex 3D models. In this paper, the development and evaluation of a VR-based tool to support engineering design review is described. “VRSmart” visualizes CAD data and allows for an intuitive interaction. In a preliminary user study, the tool was checked for its usability and user experience. VRSmart was then evaluated in a real industrial environment and tested in an authentic design review. The results indicate that a VR-supported design review allows users to see slightly more faults in a 3D model than in a CAD software-based approach on a PC screen. Furthermore, VR reduces the risk of exclusion of certain professional groups from the design review process. In addition, the intuitive interaction with the VR system allowed for a much faster entry into the design review. In summary, VR will not replace the traditional design review process on screen, but it provides a useful addition to engineering companies.

Push-pull direct modeling of solid CAD models

Direct modeling is a very recent CAD modeling paradigm featuring direct, intuitive push-pull interactions with the geometry of the model to much increase model editing flexibility. The major issue for push-pull direct modeling is the possible inconsistency between the altered geometry of the model and its unchanged topology. The challenge of resolving the geometry-topology inconsistency lies in ensuring that the resulting model remains as a valid solid model and that the model shape follows a continuous change pattern. Although push-pull direct modeling has been implemented in several CAD software packages, robustness towards generating valid modeling results and continuous shape changes still remains an open issue. This paper proposes a systematic method to handle the resolution of any possible inconsistent situation. The method formulates the continuous shape change requirement as successive Boolean operations on the model volume, thereby guaranteeing valid solid models and continuous shape changes. Further, this formulation allows an easy implementation of push-pull direct modeling using existing CAD research and engineering results. In order to show the effectiveness of the proposed method, a software prototype is developed and the modeling results are compared with those of five leading CAD software packages.

Additive Manufacturing Rectangular Lattice Structure Design Automation

Additive Manufacturing (AM) technology provides new opportunities to automatically fabricate parts with complicated shapes that could not be produced by conventional manufacturing processes, thus enabling unprecedented design flexibilities and application opportunities. The design and analysis of lattice structures manufactured using additive manufacturing technique is a new approach to create lightweight high-strength components. Infill percentage and lattice pattern influence print weight, material usage, strength, print time and sometimes decorative properties. With many types of lattice structure patterns available, This Paper focuses on design of rectangular lattice structure according to required infill percentage. Rectangular beam is considered for application of design methodology and the rectangular lattice structure is generated with infill percentage as an input parameter. The manual process of lattice structure design is tedious and time consuming and requires many iterations to achieve final design. Therefore, the focus of this paper is to develop methodology for automatic lattice structure generation using CAD Application Programming Interface(API). The design process is automated using integration of CAD software packages Creo© parametric 4.0 and Mathcad 4.0.

Reverse engineering of mechanical parts: A template-based approach

Abstract Template-Based reverse engineering approaches represent a relatively poorly explored strategy in the field of CAD reconstruction from polygonal models. Inspired by recent works suggesting the possibility/opportunity of exploiting a parametric description (i.e. CAD template) of the object to be reconstructed in order to retrieve a meaningful digital representation, a novel reverse engineering approach for the reconstruction of CAD models starting from 3D mesh data is proposed. The reconstruction process is performed relying on a CAD template, whose feature tree and geometric constraints are defined according to the a priori information on the physical object. The CAD template is fitted upon the mesh data, optimizing its dimensional parameters and positioning/orientation by means of a particle swarm optimization algorithm. As a result, a parametric CAD model that perfectly fulfils the imposed geometric relations is produced and a feature tree, defining an associative modelling history, is available to the reverse engineer. The proposed implementation exploits a cooperation between a CAD software package (Siemens NX) and a numerical software environment (MATLAB). Five reconstruction tests, covering both synthetic and real-scanned mesh data, are presented and discussed in the manuscript; the results are finally compared with models generated by state of the art reverse engineering software and key aspects to be addressed in future work are hinted at. Highlights A novel CAD reconstruction method fitting a CAD template model to mesh data. A feature-based parametric-associative modelling history is retrieved. Fitting process is controlled by a Particle Swarm Optimization algorithm. Accuracy of reconstructed models is comparable/better than state of the art results. Computational costs and required time are at the moment considerable.

Trials, Tribulations, and Some Success in Developing Modeling Tools for the Electrochemical Industry

The fundamentals of computational modeling of current distribution in electrochemical cells have been known and practiced in academic settings since the early 50’s. However, unlike conventional chemical facilities, electrochemical cells were still being designed empirically in the 80’s and 90’s, and to significant extent, empiricism prevails in the electrochemical industry even today. The underlying reasons for this slow penetration of modeling applications are discussed. The advent of personal computers in the early 80’s presented an opportunity to provide wide access to quantitative modeling throughout the electrochemical industry. The considerations that guided the design of the first commercial CAD software package of electrochemical cells, “Cell-Design”, and its commercialization strategy are presented, including the roles of industry and government in this endeavor. By the late 80’s and throughout the 90’s additional software packages, with different features and marketing strategies became available. The relatively recent introduction of an electrochemical module to Comsol, presented yet another stage in modeling capabilities of electrochemical cells that became accessible to the industry. The different features and marketing strategies of the different modeling packages are described. A major barrier to wide-spread penetration of quantitative modeling within the electrochemical industry has been the lack of property data, particularly as related to many different plating solutions with proprietary additives. To overcome this limitation, that affects mostly the small plating companies with limited access to electroanalytical tools and expertise, the “L-Cell”, a device for fast determination of kinetics parameters, has been introduced. The capabilities, advantages, and limitations of this instrument, in comparison to other tools, ranging from automated and specialized devices to the aging and simplistic, but still widely used, “hull-Cell”, are discussed. Challenges facing the electrochemical industry and opportunities that will enable it to meet future technological needs, including, but not limited to modeling capabilities, are critically discussed. Tasks that can be best carried out in academic institutions and others that are more effectively accomplished in industry and the interactions between the two, based on the author’s experience, are presented.