Computer-aided Design Software Research Articles

Design and simulation of scaffolds with lattice microstructures for bioprinting bone tissue.

Tissue engineering seeks to improve, maintain, or replace the biological functions of damaged organs or tissues with biological substitutes such as the development of scaffolds. In the case of bone tissue, they must have excellent mechanical properties like native bone. In this work, three geometric models were designed for scaffolds with different structure lattices and porosity that could be biomechanically suitable and support cell growth for trabecular bone replacement applications in tissue engineering and regenerative medicine to the proximal femur area. Geometries were designed using computer-aided design (CAD) software and evaluated using finite element analysis in compression tests. Three loads were considered according to the daily activity: 1177 N for slow walking, 2060N for fast walking, and 245.25 N for a person in a bipedal position. All these loads for an adult weight of 75 kg. For each of them, three biomaterials were assigned: two polymers (poly-glycolic acid (PGA) and poly-lactic acid (PLA)) and one mineral (hydroxyapatite (HA)). 54 tests were performed: 27 for each of the tests. The results showed Young's modulus (E) between 1 and 4 GPa. If the resultant E is in the range of 0.1 to 5 GPa, the biomaterial is considered an appropriate alternative for the trabecular bone which is the main component of the proximal bone. However, for the models applied in this study, the best option is the poly-lactic acid which will allow absorbing the acting loads.

Impact of smoothing interpolations on the non-conventional machining of pockets

Smoothing curves have been used in computer aided design software for years. This is the reason why machinists very early wondered about the possibilities of creating toolpaths directly generated from this type of mathematical curves. In addition, in recent research work, we have shown that the non-uniform rational Bspline interpolation is the most favorable towards high-speed machining of complex shapes. As a result, we are thinking of simulating by this type of interpolation the pocket recess machining strategies proposed by a computer aided manufacturing software, currently developed in linear and circular interpolations only. In this article we propose a study of the influence of the parameters of Bspline curves on the hollowing out of pockets by smoothing initial cutting methods. To do this, we chose the smoothing of the zigzag method by Bspline and NURBS while varying the order and the discretization parameters to know the impact on the dynamics of the high-speed machining mechanism and on the non-conventional machining precision. This work has shown that parametric curves are favored for this type of machining provided that this tool is mastered.

Recursive autoencoder network for prediction of CAD model parameters from STEP files

Databases of 3D CAD (computer aided design) models are often large and lacking in meaningful organisation. Effective tools for automatically searching for, categorising and comparing CAD models, therefore, have many potential applications in improving efficiency within design processes. This paper presents a novel asymmetric autoencoder model, consisting of a recursive encoder network and fully-connected decoder network, for the reproduction of CAD models through prediction of the parameters necessary to generate a 3D part design. Inputs to the autoencoder are STEP (standard for the exchange of product data) files, an ISO standard CAD model format, compatible with all major CAD software. A complete 3D model can be accurately reproduced using a STEP file, meaning that all geometric information can be used to contribute to the final encoded vector, with no loss of small detail.In a CAD model of overall size 10 × 10 × 10 units, for 90% of models, the class of an added feature is estimated with maximum error of 0.6 units, feature size with maximum error of 0.4 units and coordinate values representing position with maximum error of 0.3 units. These results demonstrate the successful encoding of complex geometric information, beyond merely the shape of the 3D object, with potential application in the design of search engine functionality.

A method for estimating the contact area of a dual-mobility total hip prosthesis

The term “contact area” refers to the total surface area of two entities in direct physical touch. When discussing an artificial hip joint, “contact area” refers to the surface area of contact between the components of the artificial hip joint (ball and cup) positioned inside the patient. Several methods can be used to figure out the contact area of an artificial hip joint, such as finite element analysis and traditional experiments on contact mechanics with hip joint simulators. The contact area in an artificial hip joint ensures load distribution. For optimal and long-term performance, the prosthetic hip joint’s contact area must be well understood for design, fitting, and monitoring. This study presented a novel method to estimate the liner surface contact area due to interaction contact in the artificial hip joint using a computer-aided design (CAD) program. This study also contrasted numerical approaches utilizing computer-aided engineering software and theoretical predictions based on Hertz theory with three-dimensional processes using CAD software to determine the contact area in the inner liner. There were no significant discrepancies in the outcomes of the three approaches.

Analysis of Car Vehicle Seat Noise Under Different Forces

The noise and rattling have been a problem constantly due to how it disturbs customers' comfort while driving. The objective of this project was to conduct the analysis for seat noise and to analyse the effect of different force and material for car seat. The main purpose of this study is to analyse the effect of different force and material for car seat. Seat model design was generated by using Computer-Aided Design (CAD) software which is SolidWorks 2020. Seat model was then analysed using Computer-Aided Engineering (CAE) which is ANSYS 2022 R1. This inquiry focuses on the data and graphs collected during the simulation, which was performed using the ANSYS. The data is then uploaded to Microsoft Excel, to be utilised to create graphs illustrating the PSD of displacement and acceleration of the vehicle seat when loads are applied to it. A simulation was run to analyse the noise on car seat. The characteristics of vibration of car seat for different type of material and different force was visualized. The comparison of different type of material and force has been investigated in the present study. Static structural analysis on car seat has been performed on different types of material and force by using ANSYS software to analyse total deformation, stress, and strain.

3D Specimen Scanning and Mapping in Musculoskeletal Oncology: A Feasibility Study.

Surgical resection is the primary treatment for bone and soft tissue tumors. Negative margin status is a key factor in prognosis. Given the three-dimensional (3D) anatomic complexity of musculoskeletal tumor specimens, communication of margin results between surgeons and pathologists is challenging. We sought to perform ex vivo 3D scanning of musculoskeletal oncology specimens to enhance communication between surgeons and pathologists. Immediately after surgical resection, 3D scanning of the fresh specimen is performed prior to frozen section analysis. During pathologic grossing, whether frozen or permanent, margin sampling sites are annotated on the virtual 3D model using computer-aided design (CAD) software. 3D scanning was performed in seven cases (six soft tissue, one bone), with specimen mapping on six cases. Intraoperative 3D scanning and mapping was performed in one case in which the location of margin sampling was shown virtually in real-time to the operating surgeon to help achieve a negative margin. In six cases, the 3D model was used to communicate final permanent section analysis. Soft tissue, cartilage, and bone (including lytic lesions within bone) showed acceptable resolution. Virtual 3D scanning and specimen mapping is feasible and may allow for enhanced documentation and communication. This protocol provides useful information for anatomically complex musculoskeletal tumor specimens. Future studies will evaluate the effect of the protocol on positive margin rates, likelihood that a re-resection contains additional malignancy, and exploration of targeted adjuvant radiation protocols using a patient-specific 3D specimen map.

Three-dimensional Architecture of Carbon Nanotube Transistors with High Speed and Performance

Transistors, essential components of contemporary electronics, are crucial in providing electricity for the technology-dependent society. Given the continuously growing need for enhanced speed capabilities in electronic devices, it has become crucial to investigate innovative materials and structures to fulfill these demands. Carbon Nanotubes (CNTs) have emerged as a desirable contender due to their remarkable electrical characteristics, characterized by elevated carrier mobility and nanoscale dimensions. This study explores the importance of high-speed performance in the contemporary technology-driven environment and emphasizes the crucial role played by transistors in attaining this objective. This research underscores the distinctive attributes of CNTs, including their exceptional electrical conductivity, mechanical robustness, and dimensions, making them a highly suitable contender for advanced transistors in future applications. The current transistor layouts encounter notable obstacles in effectively using the whole capabilities of CNTs, such as the difficulty associated with achieving accurate alignment and addressing connection concerns. To tackle the issues, this study presents a novel three-dimensional CNT Architecture (3D-CNTA) design that utilizes state-of-the-art Computer-Aided Design (CAD) software to achieve accurate spatial modeling. The 3D-CNTA that has been suggested exhibits exceptional performance in several aspects, encompassing power consumption (0.3 Watts), noise (2.6 microvolts), delay (6.6 nanoseconds), gain (36.25 dB), energy efficiency (2.13 femtojoules per transition), and simulation accuracy (95%).

Enhanced Communication of Tumor Margins Using 3D Scanning and Mapping.

After oncologic resection of malignant tumors, specimens are sent to pathology for processing to determine the surgical margin status. These results are communicated in the form of a written pathology report. The current standard-of-care pathology report provides a written description of the specimen and the sites of margin sampling without any visual representation of the resected tissue. The specimen itself is typically destroyed during sectioning and analysis. This often leads to challenging communication between pathologists and surgeons when the final pathology report is confirmed. Furthermore, surgeons and pathologists are the only members of the multidisciplinary cancer care team to visualize the resected cancer specimen. We have developed a 3D scanning and specimen mapping protocol to address this unmet need. Computer-aided design (CAD) software is used to annotate the virtual specimen clearly showing sites of inking and margin sampling. This map can be utilized by various members of the multidisciplinary cancer care team.

Integrating Computer Vision and CAD for Precise Dimension Extraction and 3D Solid Model Regeneration for Enhanced Quality Assurance

This paper focuses on the development of an integrated system that can rapidly and accurately extract the geometrical dimensions of a physical object assisted by a robotic hand and generate a 3D model of an object in a popular commercial Computer-Aided Design (CAD) software using computer vision. Two sets of experiments were performed: one with a simple cubical object and the other with a more complex geometry that needed photogrammetry to redraw it in the CAD system. For the accurate positioning of the object, a robotic hand was used. An Internet of Things (IoT) based camera unit was used for capturing the image and wirelessly transmitting it over the network. Computer vision algorithms such as GrabCut, Canny edge detector, and morphological operations were used for extracting border points of the input. The coordinates of the vertices of the solids were then transferred to the Computer-Aided Design (CAD) software via a macro to clean and generate the border curve. Finally, a 3D solid model is generated by linear extrusion based on the curve generated in CATIA. The results showed excellent regeneration of an object. This research makes two significant contributions. Firstly, it introduces an integrated system designed to achieve precise dimension extraction from solid objects. Secondly, it presents a method for regenerating intricate 3D solids with consistent cross-sections. The proposed system holds promise for a wide range of applications, including automatic 3D object reconstruction and quality assurance of 3D-printed objects, addressing potential defects arising from factors such as shrinkage and calibration, all with minimal user intervention.

Optimising Amber Processing Using 3D Scanning: New Perspectives in Cultural Heritage

This article aims to present the practical and functional application of advanced 3D scanning technologies in the process of designing products made of amber. The processing of amber is complex and expensive because mass or serial production is not possible. Moreover, processing is challenging because each product is treated as unique and requires individual handling. The optimisation process is illustrated using the example of amber blocks that were scanned to obtain virtual 3D models. The scope of this work includes the characterisation of three-dimensional jewellery design processes, along with a description of a wide range of methods and functions used in computer-aided jewellery design. The use of computer-aided design software for developing virtual models of decorative products used in goldsmithing is described in this paper. The obtained sets of models underwent engineering analysis using Boolean algebra and data science calculations. In this way, a design methodology was developed regarding the selection of input material as the unprocessed stone for jewellery modelling. The developed method allows for the minimisation of material waste, which is associated with reducing costs in the processing of amber. This article also describes the differences between previous traditional methods and the authors’ proprietary method. The proposed methodology can be implemented in jewellery workshops specialising in the processing of materials.

3D modeling of the airflow and aerosol deposition in the existence of dust

Annually, more than two million deaths are caused due to the exposure of air pollution which cause damage to the lungs and the respiratory system. Topography, light-textured topsoil, drought, and desert climate make Saudi Arabia vulnerable to sand storms and dust. The study aims to examine the deposition of dust particles in the human airway and its relationship to asthma and investigate the possibility that the dust deposition would be changed with different particle size diameters. An idealized upper respiratory tract 3D model was constructed with computer-aided design software. Later a computational simulation was performed using computational fluid dynamics with 3 different sizes (0.03, 2, and 9 microns) of the dust particles to find out the change in airflow velocity and pressure. Our findings revealed that small size particles will travel more with less inertia, whereas bigger size particles will travel less but with higher inertia at airflow rates of 30 L/min. It was found that dust deposition in the respiratory system determines the probability of inhalation and total deposition in the alveoli greatly varies with particle diameter size. An idealized URT model replicate patient-specific URT geometry which helped in finding real-time airflow velocity and pressure of dust particles. Particles with smaller diameter are capable of 100% deposition and inhalation rate at the alveoli, whereas particles with bigger diameter tend to deposit less and with lower inhalation rates at the alveoli.

Deep learning-based automated detection of the dental crown finish line: An accuracy study

Statement of problemThe marginal fit of dental prostheses is a clinically significant issue, and dental computer-aided design software programs use automated methods to expedite the extraction of finish lines. The accuracy of these automated methods should be evaluated. PurposeThe purpose of this study was to compare the accuracy of a new hybrid method with existing software programs that extract finish lines using fully automated and semiautomated methods. Material and methodsA total of 182 jaw scans containing at least 1 natural tooth abutment were collected and divided into 2 groups depending on how the digital data were created. Group DS used desktop scanners to scan casts trimmed for improved finish line visibility, while Group IS used intraoral scans. The method from Dentbird was compared using 3 software packages from 3Shape, exocad, and MEDIT. The Hausdorff and Chamfer distances were used in this study. Three dental laboratory technicians experienced in the digital workflow evaluated clinical finish line acceptance and its Hausdorff and Chamfer distances. For statistical analysis, t tests were performed after the outliers had been removed using the Tukey interquartile range method (α=.05). ResultsOutliers identified by using the Tukey interquartile range method were more numerous in the semiautomatic methods than in the automatic methods. When considering data without outliers, the software performance was found to be similar for desktop scans of the trimmed casts. However, the method from Dentbird demonstrated statistically better results (P<.05) for the posterior tooth with finish lines in concave regions than the 3Shape, exocad, and MEDIT software programs. Furthermore, thresholds coherent with clinical acceptance were determined for the Hausdorff and Chamfer distances. The Hausdorff distance threshold was 0.366 mm for desktop scans and 0.566 mm for intraoral scans. For the Chamfer distance, the threshold was 0.026 for desktop scans and 0.100 for intraoral scans. ConclusionsThe method from Dentbird demonstrated a comparable or better performance than the other software solutions, particularly excelling in finish line extraction for intraoral scans. Using a hybrid method combining deep learning and computer-aided design approaches enables the robust and accurate extraction of finish lines.

Methodology and application of three-dimensional technology for brace design and production for treatment in patients with adolescent idiopathic scoliosis: a scoping review protocol

IntroductionConservative treatment for adolescent idiopathic scoliosis (AIS) using bracing has proven to be effective at reducing curve progression. However, variation in brace design and lack of brace specificity hamper clinical...

Impact of marginal defects on the accuracy of automated finish line detection in tooth preparation.

The present study aimed to evaluate the accuracy of automated detection of preparation finish lines in teeth with defective margins. An extracted first molar was prepared for a full veneer crown, and marginal defects were created and scanned (discontinuity of finish line: 0.5, 1.0, and 1.5 mm; additional line angle: connected, partially connected, and disconnected). Six virtual defect models were entered into CAD software and the preparation finish line was designated by 20 clinicians (CAD-experienced group: n = 10; CAD-inexperienced group: n = 10) using the automated finish line detection method. The accuracy of automatic detection was evaluated by calculating the 3D deviation of the registered finish line. The Kruskal-Wallis and Mann-Whitney U tests were used for between-group comparisons (α = 0.05). The deviation values of the registered finish lines were significantly different according to conditions with different amounts of finish line discontinuity (P < 0.001). There was no statistical difference in the deviation of the registered finish line between models with additional line angles around the margin. Moreover, no statistical difference was found in the results between CAD-experienced and CAD-inexperienced operators. The accuracy of automated finish line detection for tooth preparation can differ when the finish line is discontinuous. The presence of an additional line angle around the preparation margin and prior experience in dental CAD software do not affect the accuracy of automated finish line detection.

TCAD simulations of internal amplification in high purity germanium detectors

Simulations of internal amplification processes in high purity germanium (HPGe) detectors for gamma radiation are presented. The Synopsys Sentaurus Technology Computer-Aided Design (TCAD) package was employed to study conditions favourable to charge multiplication within volume of the detector. The physics model was developed, and validated where possible against known results from existing literature. The model was then applied to a new detector and a systematic study of the measurable parameters influencing charge collection and electric field profile was performed. Evidence of the internal amplification in the developed HPGe detector model was demonstrated at 4 kV bias voltage with anode diameter below 100 μm, corresponding to 16 kV/cm electric field and when an additional dopant with concentrations >5×1010cm−3 under the anode implanted. These effects were also simulated and observed in silicon detectors, giving additional confidence in the validity of the findings for germanium, presented in this work.

Effect of roof design on wind load of buildings through numerical simulation

When the wind blows against a building, the resulting force acting on the building at a particular elevation is called the wind load. Measuring and minimizing the wind load is crucial to ensure the safety of buildings. Therefore, the objective of this study is to investigate the effect of a buildings roof design on the wind load by evaluating and comparing the wind pressure differences p that different building models experience by leveraging Computational Fluid Dynamics (CFD) simulations. The 3D CAD (Computer-Aided Design) software SolidWorks was used to construct building models of identical dimensions with the exception of roofs harboring different shapes and angles. By exerting a wind velocity through flow simulation, flow trajectories and cut plot graphs of wind velocity and pressure surrounding the building models are generated. Wind pressure differences p for each situation were calculated and compared based on the CFD results. Wind tunnel experimentation with building models will also executed to test the computed data and prove its reliability and applicability. The data shows that, among all tested roof designs, the barrel-vaulted roof exhibits the minimum pressure difference (of 171.15 Pa) between the windward and the leeward surface and experiences the least wind load and resists strong wind most effectively. It reduces up to roughly 15% of wind load compared to the worst case tested. For symmetric triangular gable roof designs, the greater base angle leads to greater wind load. Overall, this study provides the theoretical basis and scientific evidence for the building designs of the next generation.

A novel dice-inspired multifunctional 3D printing guided splint for minimally invasive access cavity preparation and canal orifice identification.

The minimally invasive endodontics could retain more peri-cervical dentin (PCD) and other important dental structures, thus realizing the minimal loss of teeth structures and preserving the strength and function of the endodontically treated tooth (ETT). The search for abnormal root canals or calcified root canals could be quite time-consuming and increase the risk of perforation. This study introduced a novel multifunctional 3D printing guided splint inspired by the dice, which can achieve the minimally invasive access cavity preparation and canal orifice identification. Data were collected from an outpatient with dens invaginatus. Cone-beam Computed Tomography (CBCT) revealed a type III invagination. The CBCT data of the patient were imported into a computer-aided design (CAD) software (Exocad 3.0; Exocad GmbH) for the 3D reconstruction of jaw bones and teeth. The dice-inspired 3D printing guided splint consists of the sleeve and guided splint. The sleeve with minimal invasive opening channel and orifice locating channel were designed with a reverse-engineering software (Geomagic Wrap 2021). The reconstructed models in the Standard Template Library (STL) format were imported into a CAD software. The design of the template was aided by the dental CAD software in Splint Design Mode. The sleeve and splint were exported into the STL files separately. A 3D printer (ProJet® 3600 3D Systems) was used to separately generate the sleeve and guided splint, and was made by stereolithography and processed in a medical resin (VisiJet M3 StonePlast). The novel multifunctional 3D printing guided splint could be set in position. The opening side in the sleeve was selected and the sleeve was inserted in place. The minimal invasive opening was made in the crown of the tooth to access the pulp. The sleeve was draw out and turned to the orifice location side, and then inserted in place. The target orifice was located rapidly. This novel dice-inspired multifunctional 3D printing guided splint allow dental practitioners to gain accurate, conservative, and safe cavity access from teeth with anatomical malformations. Complex operations might be carried out with less reliance on the operator's experience than with conventional access preparations. This novel dice-inspired multifunctional 3D printing guided splint would have a broad application in the dental field.

Benefits of Building Information Modeling (BIM) Software Using IBM SPSS Statistics

Building Information Modelling software is commonly used in the architecture and construction industries for computer-aided design (CAD) and construction information modelling. These products include many tools and libraries that are especially aimed at architecture design, construction, and mechanical, electrical, and plumbing (MEP) modeling BIM software offers a process centered around models to create designs for buildings and infrastructure, and creates a digital representation of a facility's operational characteristics beyond construction drawings. Other products in this category can be used for various CAD purposes, but their main focus is on architectural design. To be included in the BIM category, a product must provide tools for 2D or 3D computer-aided design aimed at architectural design and construction. It should also include collaboration tools that allow multiple group members to work together. Additionally, it should provide performance data and analytical engines to improve building efficiency. For more information on CAD products, see our public objective CAD software type. For information on product and mechanical design software, see our product and machinery category. And for civil engineering design products, see our civil engineering design software category. In building design and BIM products, the top four influencing factors that favor user satisfaction are "sequence steps," "dynamic updating," "editing," and "preparation in doing business." These are predictable satisfaction attributes that are determined by the algorithm for users within this category. It creates detailed digital representations that integrate regulatory data and enables real-time collaboration on an open cloud platform.IBM SPSS Statistics is a software tool created by IBM that serves various purposes such as data management, advanced analytics, multivariate analytics, business intelligence, and criminal investigation. The software originated from the acquisition of SPA Inc. in 2009 and is currently known as IBM SPSS Statistics in its latest versions. In the context of the mentioned software, the Cronbach's alpha reliability result for the following applications: autocad, revit, sketchup, navisworks, archicad, aurora solar, autocad arch, and tekla structures, is recorded as 0.622. This value indicates a reliability level of 62%. Based on the findings from the literature review, this Cronbach's alpha value of 62% is considered for further analysis.

Automation of trimming die design inspection by zigzag process between AI and CAD domains

Quality control using artificial intelligence (AI) has led to considerable improvements in the manufacturing industry. However, inspection of computer-aided design (CAD) drawing to prevent potential errors is still performed manually by engineers. The design inspection which involves sequential and repetitive processes is labor-intensive, time-consuming, and prone to human error. In this study, we developed an automatic design inspection system for CAD data by integrating AI module and CAD software. The target product of this study is automobile trimming die design. The AI modules replace the engineers’ judgment, and the CAD software performs the operations requested by the AI modules. The design inspection is completed through a zigzag interaction between the AI modules and CAD software by a one-click operation without the intervention of experts. In the zigzag interaction process, 3D CAD files are converted to 2D images for interaction from the CAD software to the AI modules, and the output of the AI modules is transferred to the CAD software through VBA macros. The AI modules are designed to be CAD-independent and data-efficient; therefore, they can be easily adapted to other CAD software and achieve a high performance, even when trained with a few trimming dies. The length measurement error is only 2.4 % on average, which is at the 14th place out of 18 grades according to ISO 286–1:1988 standard tolerance. Additionally, the inspection time is reduced to approximately one-fifth of the manual inspection time by experts.

Comparison of different internal fixation implants in the treatment of talar neck fractures: A finite element analysis.

This study aimed to analyze the biomechanics of cannulated screws (CS) with or without a lateral locking plate (LLP) in talar neck fractures through a finite element analysis. The computed tomography image of the talus from a healthy volunteer (adult male) was used to reconstruct a three-dimensional talar model. The method for fixing talar neck fractures with CS and an LLP was planned using computer-aided design software. Afterward, the three-dimensional models of comminuted talar neck fractures were used to simulate fixation with anteroposterior parallel dual CS, single CS+LLP, and dual CS+LLP. Finally, finite element analysis was carried out to compare the outcomes of dual CS+LLP to those of single CS+LLP and to those of using dual CS alone. The displacement and von Mises stress values of the three groups with different internal fixation were analyzed. For a simple talar neck fracture, the lowest amount of displacement was obtained with CS+LLP (0.407 mm), while dual CS (0.459 mm) showed the highest amount of total displacement; the lowest amount of peak stresses was obtained with CS+LLP (5.38 MPa), while dual CS (8.749 MPa) showed the highest amount of total peak stresses. For a comminuted talar neck fracture, the lowest amount of displacement was obtained with CS+LLP (0.398 mm), while dual CS (0.408 mm) showed the highest amount of total displacement; the lowest amount of peak stresses was obtained with CS+LLP (129.9 MPa), while dual CS (205.9 MPa) showed the highest amount of peak stresses. Compared to the other two groups, the dual CS+LLP group had better biomechanics properties in the displacement and stress peak of the talus and implant. Thus, the use of dual CS+LLP fixation is recommended for the surgical treatment of comminuted talar neck fractures.