Commercial Computer-aided Design Software Research Articles

Design and Implementation of a Three-Dimensional CAD Graphics Support Platform for Pumps Based on Open CASCADE

In the pump industry, designers commonly utilize mainstream three-dimensional computer-aided design (CAD) software (Unigraphics NX 12.0 and SolidWorks 2023). However, these CAD packages are generic and not optimized for the specific requirements of the pump industry. This leads to a lack of flexibility and increased complexity in their usage, as well as higher computational demands, resulting in elevated learning and operational costs. Additionally, there are concerns about potential information leaks and software restrictions. In this paper, we studied the organization architecture of commercial three-dimensional CAD software, and compared and analyzed the geometric kernels and rendering engines of mainstream three-dimensional software. Using the Open CASCADE geometric kernel and OpenSceneGraph rendering engine, together with the Visual Studio 2021 development environment and Qt interface library, we developed an autonomous copyright three-dimensional CAD graphics support platform for pumps. Based on the three-dimensional platform, we tested the commonly used graphics elements and basic algorithms required for pump modeling, and successfully designed and modeled the impeller and volute casing of a centrifugal pump. Through computational simulations and experimental verifications, we demonstrated that the accuracy and precision of the pump model designed on this platform meets the design requirements, indicating that this platform has practical pump design and modeling capabilities. Compared to commercial three-dimensional CAD software, this platform exhibits superior flexibility and interactivity in three-dimensional modeling that is specifically tailored for pump products. Consequently, it fully satisfies the needs for three-dimensional parameterized modeling and visualization of pumps.

Parametric model of aircraft external geometry as a component of FAST-OAD aircraft preliminary design system.

Rapid evolutions in fields such as aerospace propulsion, materials engineering, geometry modelling tools or optimization tools provide the opportunity to search for novel configurations of future aircraft in an expanding domain. In order to effectively explore the space of variables of constantly expanding size, one needs tools that give the ability to automate this process. Such a tool is the Future Aircraft Sizing Tool for Overall Aircraft Design or FAST-OAD. FAST-OAD allows for rapid estimation of aircraft size, based on set, so-called Top Level Aircraft Requirements (TLARs) by using multi-disciplinary and multi-fidelity analysis and optimization.An essential component of such a system is a module capable of modelling the external geometry of the calculated case. This article describes an attempt to use a powerful commercial Computer Aided Design software, Siemens NX, to model the aircraft external geometry based on the results of the analysis performed by FAST-OAD. This approach, compared to previous works, brings some limitations but, on the other hand, gives the possibility to base the geometry on a mathematically consistent model and helps to better understand the set of parameters necessary to describe the geometry correctly.The main objective of this research is to provide a tool that allows the automatic generation of aircraft exterior geometry based on the output parameters received from the FAST-OAD package.An additional goal of this activity is to determine the parameter set necessary to properly define the external geometry, but at the same time not containing redundant, dependent geometric parameters. The minimum number of independent parameters necessary to completely describe the external geometry is sought.

Computer-Aided Sketching: Incorporating the Locus to Improve the Three-Dimensional Geometric Design

This article presents evidence of the convenience of implementing the geometric places of the plane into commercial computer-aided design (CAD) software as auxiliary tools in the computer-aided sketching process. Additionally, the research considers the possibility of adding several intuitive spatial geometric places to improve the efficiency of the three-dimensional geometric design. For demonstrative purposes, four examples are presented. A two-dimensional figure positioned on the flat face of an object shows the significant improvement over tools currently available in commercial CAD software, both vector and parametric: it is more intuitive and does not require the designer to execute as many operations. Two more complex three-dimensional examples are presented to show how the use of spatial geometric places, implemented as CAD software functions, would be an effective and highly intuitive tool. Using these functions produces auxiliary curved surfaces with points whose notable features are a significant innovation. A final example provided solves a geometric place problem using own software designed for this purpose. The proposal to incorporate geometric places into CAD software would lead to a significant improvement in the field of computational geometry. Consequently, the incorporation of geometric places into CAD software could increase technical-design productivity by eliminating some intermediate operations, such as symmetry, among others, and improving the geometry training of less skilled users.

Auto-assessment tools for mechanical computer aided design education

Traditionally Computer Aided Design (CAD) courses have been carried out in computer classrooms requiring great amount of teaching personnel. Assessment of students' modeling exercises has been both time consuming and error prone. Utilization of the teaching resources could clearly benefit from online auto-assessment. The auto-assessment tools are widely in use in programming and language courses, but suitable tools for assessing 3D models used in CAD are lacking. This paper presents two new online auto-assessment tools to support the development of both command (“what steps are needed to create this shape?”) and strategic (“how should I model this shape?”) knowledge while learning CAD. The first tool is based on neutral file format (in this case STEP) and can recognize surface differences between student's model and reference model. This tool can assess student's skill to create certain predefined shape (i.e. command knowledge). The second auto-assessment tool utilizes commercial CAD software's API (Application Programming Interface) to test how student's model behaves when modeling parameters are changed. This tool assess student's capabilities to build and design a CAD model's design intent (i.e. strategic knowledge). Developed tools were tested on three mechanical engineering courses. This paper presents both the tools and the feedback received from the students and teachers. Overall, the auto-assessment tools functioned well and feedback from both students and teachers were positive. The most appreciated tool functionality was time and place independent submission and assessment of exercise works. These new tools able focusing teachers' workload from checking the basic exercises to guiding the learning process.

Three-dimensional solid reconstruction of a human bone from CT images using interpolation with triangular Bézier patches

We propose an approach for the three-dimensional solid reconstruction of a human bone using medical images obtained from Computed tomography (CT). CT images of the female from the Visible Korean (VK) data set, which were constructed in the VK human project, were used. First, the femur and hip bone images were segmented from the original image. The segmented images were then smoothed by a Gaussian filter, and a triangular mesh was generated using the marching-cubes algorithm. To reduce the triangles in the generated mesh and eliminate aliasing, a triangle decimation algorithm using the quadric error metric method was adopted. To reconstruct the surfaces, the triangles in the mesh were interpolated with cubic triangular Bezier patches. The patches were then converted to a solid by stitching them. Finally, it is demonstrated that the proposed approach can be used in a practical design environment by importing the reconstructed solids into a commercial computer-aided design software.

A Preliminary Design System for Turbine Discs

AbstractIn order to improve product development cycle, design engineers use multidisciplinary analysis tools which allow for better productivity. This paper covers the development of new tools to improve the preliminary design phase of turbine disc, being a critical part of aircraft engines. First, a new single platform D&A (Design & Analysis) tool integrating commercial CAD (Computer Aided Design) and FEA (Finite Element Analysis) software processing in batch mode is presented. This integrated architecture leads to a real improvement, enabling a cohesive single integrated simulation environment that offers significant time reduction on user manipulation and execution. An optimization of disc geometry is then performed by using different optimization algorithms and configurations for a given disc parameterized model. The results show potential improvement over the current preliminary rotor discs for life and burst limited design. Finally, optimal curves obtained by developing HPT (High Pressure Turbine) disc reference charts, indicate how to get the minimum weight for given mechanical performance without running any structural analysis. These new tools supporting disc design have allowed improvement of disc life and durability leading to a reduction of preliminary design phase duration.

Intelligent DMU Creation: Toleranced Part Modelling to Enhance the Digital Environment

This paper describes a method for the consideration of tolerance stack ups in the computer-aided design (CAD) environment as design concepts are developed into digital mock ups (DMUs). The method functionality includes the capability to create maximum (MMC) and least material condition (LMC) versions of the nominally sized components, allowing the three sets of entities to co-exist while respecting the positional constraints of the nominal master model. As the user switches between MMC and LMC combinations across a number of components, the overall dimensions of the assembly within the DMU change accordingly. The assembly constraints are regenerated through an equivalencing method based on surface properties, to respect the assembly intention. The new DMU, therefore, is an improved reflection of ‘as manufactured’ part forms making assembly analysis and the allocation of tolerances more accurate at the conceptual design stage, a novel function not currently available in commercial CAD software.

Superconducting Digital Circuit Design With an Open Source and Freeware Tool Chain

Superconducting digital circuits have been around for decades, but recent projects that exploit such circuits for low-power, high-performance computing are rapidly maturing superconducting circuit technologies. As a result of increasing circuit complexity, there is renewed focus on superconducting digital circuit design tools. Until now, most computer-aided design (CAD) tool development for superconducting electronics (SCE) circuit design has been based on calibrating semiconductor tools, rather than creating new technology-specific tools for the SCE circuit design. The recent development shows bias toward large and expensive CAD tools. These tools, or modules developed for commercial semiconductor CAD tools, require users to have access to an expensive commercial semiconductor CAD software, which places it out of the reach of new entrants or small research groups in SCE. In this paper, the open-source tools that can be used as alternatives to form an SCE design tool chain are described. All the design stages in an SCE integrated circuits design flow, from circuit specification down to layout design, are noted in this paper. Each stage is discussed and the available open-source tools are described. The inherent disadvantages of these open-source tools are also pointed out. A design example is then provided to demonstrate a complete open source and freeware tool chain.

Innovative approach to computer-aided design of horizontal axis wind turbine blades

Abstract The design of horizontal axis wind turbine (HAWT) blades involves several geometric complexities. As a result, the modeling of these blades by commercial computer-aided design (CAD) software is not easily accomplished. In the present paper, the HAWT blade is divided into structural and aerodynamic surfaces with a G1 continuity imposed on their connecting region. The widely used method of skinning is employed throughout the current work for surface approximation. In addition, to ensure the compatibility of section curves, a novel approach is developed based on the redistribution of input airfoil points. In order to evaluate deviation errors, the Hausdorff metric is used. The fairness of surfaces is quantitatively assessed using the standard strain energy method. The above-mentioned algorithms are successfully integrated into a MATLAB program so as to enhance further optimization applications. The final surfaces created by the procedure developed during the present study can be exported using the IGES standard file format and directly interpreted by commercial CAD and FE software. Highlights A new skinning approach is presented based on redistribution of input data points. The developed skinning method is successfully applied to the design of horizontal axis wind turbine blades. It has been shown that the blade surface constructed using the developed method is fair and visually pleasing. Special attention has been paid to construct a smooth surface in the transition area between the root and the section with maximum chord.

Methodologies for Development of Patient Specific Bone Models from Human Body CT Scans

This work deals with development of algorithm for physical replication of patient specific human bone and construction of corresponding implants/inserts RP models by using Reverse Engineering approach from non-invasive medical images for surgical purpose. In medical field, the volumetric data i.e. voxel and triangular facet based models are primarily used for bio-modelling and visualization, which requires huge memory space. On the other side, recent advances in Computer Aided Design (CAD) technology provides additional facilities/functions for design, prototyping and manufacturing of any object having freeform surfaces based on boundary representation techniques. This work presents a process to physical replication of 3D rapid prototyping (RP) physical models of human bone from various CAD modeling techniques developed by using 3D point cloud data which is obtained from non-invasive CT/MRI scans in DICOM 3.0 format. This point cloud data is used for construction of 3D CAD model by fitting B-spline curves through these points and then fitting surface between these curve networks by using swept blend techniques. This process also can be achieved by generating the triangular mesh directly from 3D point cloud data without developing any surface model using any commercial CAD software. The generated STL file from 3D point cloud data is used as a basic input for RP process. The Delaunay tetrahedralization approach is used to process the 3D point cloud data to obtain STL file. CT scan data of Metacarpus (human bone) is used as the case study for the generation of the 3D RP model. A 3D physical model of the human bone is generated on rapid prototyping machine and its virtual reality model is presented for visualization. The generated CAD model by different techniques is compared for the accuracy and reliability. The results of this research work are assessed for clinical reliability in replication of human bone in medical field.

A web-based design support system for fashion technical sketches

Purpose – To better respond to today’s volatile and changing fashion market, the purpose of this paper is to develop a web-based design support system that enables users to design realistic and interesting skirts in the form of technical sketches over the internet. Design/methodology/approach – The proposed system mainly consists of a sketch representation and composing method (SRCM), a graphic user interface (GUI) and a controller. The SRCM is implemented at the server end that generates technical sketches according to user defined parameters and features via the web-based GUI at the client side. The controller manages the workflows between the server and the clients. Findings – To evaluate the effectiveness of the proposed system, a survey was conducted by inviting 30 subjects (professional designers or undergraduate students studying fashion design) to have trial run of the system in Hong Kong and in the USA. Positive comments and feedbacks were received, and valuable suggestions were also obtained in regard to the prototype system. Originality/value – Compared with traditional computer-aided design (CAD) systems, the proposed system is more effective and easier to operate as users can create technical sketches in accurate proportions with simple computer operations in a few mouse clicks. Besides, the output sketches are fully compatible with most commercial CAD software. The system is developed based on web technologies, thus fashion sketches can be easily designed using any computer connected to the internet; it can be implemented on Android or iOS platform in the future.

Simultaneous Evaluations of Material Toxicity and Ease of Disassembly during Electronics Design

SummaryDesign for environment (DfE) has become an important strategy for sustainable development. However, tools used for designing and tools used to conduct environmental evaluations are currently independent, and therefore the data these tools rely on are not easily communicated and integrated. In this research, we have developed a new software tool (EcoCAD) to provide support for DfE. The primary aim is to enable designers to spend less time on complicated environmental evaluations and independently and quickly develop products that have improved material toxicity and ease‐of‐disassembly characteristics.Fraunhofer‐Institut für Zuverlässigkeit und Mikrointegration's method for developing toxic potential indicators (TPIs) was used to create a Taiwanese TPI database from information contained in the United Nations’ globally harmonized system's material safety data‐sheet databases, and EcoCAD was developed and embedded on a commercial computer‐aided design (CAD) software platform. In addition to common industrial materials, the toxicity of materials in generic printed circuit boards and in generic electric/electronic components is built into EcoCAD.EcoCAD not only provides designers with a functionality for monitoring TPIs during the design process, but also provides the designer with suggestions for reducing the toxicity and improving the ease of disassembly of their products. EcoCAD is an extremely practical tool because a designer is able to understand the material toxicity and ease‐of‐disassembly characteristics of the product during the CAD modeling stage itself, thereby saving time and cost and inspiring better designs.At the present time, EcoCAD focuses on toxicity of materials and ease of disassembly, but our concept could be extended to other environmental characteristics. For example, if a suitable life cycle assessment database was integrated with commercial CAD software, greenhouse gas emissions or European Union energy‐related product directives could be considered.

An integrated disassembly constraint generation approach for product design evaluation

Computer-aided design (CAD) has been a de facto industry standard approach for common product design. Analysing the manufacturing factors of the product at its design stage can greatly reduce its cost at the later stages of product life cycle. This article presents an integrated approach of disassembly constraint generation, based on which an object-oriented prototype is designed and developed. The approach is implemented as an embedded application on commercial CAD software platform so as to provide a tight and seamless integration to CAD process. It utilises the CAD model information directly and allows designers to evaluate the on-going design for its disassembly properties. Moreover, since the modules and objects are well encapsulated, it is possible for further disassembly planning applications to build on top of or integrate to it. The case study on a widely used shaft assembly demonstrated the effectiveness of the integrated approach.

65-, 45-, and 32-nm Aluminium and Copper Transmission-Line Model at Millimeter-Wave Frequencies

An improved analytical model of the CMOS 65-, 45-, and 32-nm silicon technology integrated transmission line is proposed. This model is derived from previous classical ones used for printed circuits board lines. Improvements have been performed to take into account the size of integrated lines. The study is validated up to millimeter-wave frequencies for different linewidths realized with various metal levels. Accurate results allow the model to be implemented in commercial computer-aided design software commonly used for millimeter-wave designs. A comparison with commercial tools is carried out.

STL rapid prototyping bio-CAD model for CT medical image segmentation

This paper presents a simple process to construct 3D rapid prototyping (RP) physical models for computer tomography (CT) medical images segmentation. The use of stereolithography (STL) triangular meshes as a basis for RP construction facilitates the simplification of the process of converting CT images to an RP model. This is achieved by constructing the STL triangular meshes directly from data points without having to draw the curve model first. The grey prediction algorithm is used to sort contour point data in each layer of the medical image. The contour difference detection operation is used to sequence the points for each layer. The 3D STL meshes are then constructed by this proposed layer-by-layer sequence meshes algorithm to build the STL file. Once this STL file is saved, a 3D physical model of the medical image can be fabricated by RP manufacturing, and its virtual reality model can also be presented for visualization. CT images of a human skull and femur bone were used as the case studies for the construction of the 3D solid model with medical images. The STL models generated using this new methodology were compared to commercial computer-aided design (CAD) models. The results of this comparative analysis show that this new methodology is statistically comparable to that of the CAD software. The results of this research are therefore clinically reliable in reconstructing 3D bio-CAD models for CT medical images.

Functional design and optimisation of parametric CAD models in a knowledge-based PLM environment

The main purpose of this paper is to present our approach to automatically generating optimised 3D Computer-aided Design (CAD) models into which all the known expert design rules are integrated, by changing only functional requirements for the same product architecture. Through the requirement specifications integrated into our ACSP Product Lifecycle Management (PLM) system (functional and product architecture parameters), we are able to generate and automatically draft/produce/test/validate/optimise a parametric product architecture and its geometric skeleton, using a commercial CAD software program. A knowledge-based engineering software program, using constraint propagation with a first-order inference engine, and a multiobjective optimisation solver are used as an interface between the PLM system and the CAD software.

Parametric modelling of helical rotors for efficient design of twin-screw superchargers

The parametric three-dimensional geometric model of twin-screw supercharger rotors of any aspect ratio was developed. For model validation through visualization, computer-aided design (CAD) rotor models with scalable data were generated in commercial CAD software and calibrated experimentally by laser Doppler velocimetry (LDV) tests. Calibrated rotor profile data can be transferred into CAD-CFD interface for flow simulation for performance optimization.

Design and thermal analysis of plastic injection mould

This paper presents the design of a plastic injection mould for producing warpage testing specimen and performing thermal analysis for the mould to access on the effect of thermal residual stress in the mould. The technique, theory, methods as well as consideration needed in designing of plastic injection mould are presented. Design of mould was carried out using commercial computer aided design software Unigraphics, Version 13.0. The model for thermal residual stress analysis due to uneven cooling of the specimen was developed and solved using a commercial finite element analysis software called LUSAS Analyst, Version 13.5. The software provides contour plot of temperature distribution for the model and also temperature variation through the plastic injection molding cycle by plotting time response curves. The results show that shrinkage is likely to occur in the region near the cooling channels as compared to other regions. This uneven cooling effect at different regions of mould contributed to warpage.

Behavioral model for reducing the complexity of mixer analysis and design

This article considers an approach for the behavioral modeling of the conversion mechanism in a nonlinear device suitable for the analysis of RF/microwave mixers. The core of the model consists of the conversion matrix of the nonlinear cell under investigation, which represents its linearization around the large-signal state. This approach allows for a straightforward implementation in Computer-Aided Design (CAD) using the conversion matrix constructed from either simulation or measurements, of which the latter is considered here. Model order is significantly reduced due to the absence of the local oscillator signal in the frequency analysis plan. The intermodulation products are calculated in relative amplitude and phase and allocated in the spectrum on the basis of the conversion matrix coefficients. We illustrate the technique by implementing this model in commercial CAD software, which allows an in-depth insight into the conversion mechanism and illustrates the application to the design of a subharmonic mixer. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005.

Automatic generation of transitional meshes

AbstractAdvances in commercial computer‐aided design software have made finite element analysis with three‐dimensional solid finite elements routinely available. Since these analyses usually confine themselves to those geometrical objects for which particular CAD systems can produce finite element meshes, expanding the capability of analyses becomes an issue of expanding the capability of generating meshes. This paper presents a method for stitching together two three‐dimensional meshes with diverse elements that can include tetrahedral, pentahedral and hexahedral solid finite elements. The stitching produces a mesh that coincides with the edges which already exist on the portion of boundaries that will be joined. Moreover, the transitional mesh does not introduce new edges on these boundaries. Since the boundaries of the regions to be stitched together can have a mixture of triangles and quadrilaterals, tetrahedral and pyramidal elements provide the transitional elements required to honor these constraints. On these boundaries a pyramidal element shares its base face with the quadrilateral faces of hexahedra and pentahedra. Tetrahedral elements share a face with the triangles on the boundary. Tetrahedra populate the remaining interior of the transitional region. Copyright © 2001 John Wiley & Sons, Ltd.