Solid Modeling and Stereolithography as a Solid Freeform Fabrication Technique at Texas Instruments Incorporated

Over the past 25 years, the CAE/CAD/CAM industry has developed technological advances that have provided industrial users the ability to increase productivity and decrease the cycle time necessary for product development. These technologies include basic wireframe and surface design, specializedapplication software packages, finite element analysis, numerical control, solid modeling, and rapid prototyping. Each of these technologies plays a significant role in industry today. The Defense Systems & Electronics Group of Texas Instruments currently uses these technologies in the mechanical design engineering process. This paper discusses the two specific technologies of solid modeling and rapid prototyping (specifically stereolithography), including their advantages, benefits, and practical applications within the Texas Instruments Defense Systems & Electronics Group. This paper also discusses the use of stereolithography (SLA) rapid~prototype parts within the solid-mold investment~casting process.Mechanical Engineerin

Integrating Deep Learning into CAD/CAE System: Generative Design and Evaluation of 3D Conceptual Wheel

Engineering design research integrating artificial intelligence (AI) into computer-aided design (CAD) and computer-aided engineering (CAE) is actively being conducted. This study proposes a deep learning-based CAD/CAE framework in the conceptual design phase that automatically generates 3D CAD designs and evaluates their engineering performance. The proposed framework comprises seven stages: (1) 2D generative design, (2) dimensionality reduction, (3) design of experiment in latent space, (4) CAD automation, (5) CAE automation, (6) transfer learning, and (7) visualization and analysis. The proposed framework is demonstrated through a road wheel design case study and indicates that AI can be practically incorporated into an end-use product design project. Engineers and industrial designers can jointly review a large number of generated 3D CAD models by using this framework along with the engineering performance results estimated by AI and find conceptual design candidates for the subsequent detailed design stage

Mechanical design automation: a case study on plastic extrusion die tooling

The Skills Gap in Mechanical Engineering (ME) Design has been widening with the increasing number of baby boomers retiring (Silver Tsunami) and the lack of a new generation to acquire, practice and perfect their knowledge base. This growing problem has been addressed with several initiatives focused on attracting and retaining young talent; however, these types of initiatives may not be timely for this new group to be trained by an established Subject Matter Expert (SME) group. Automated Engineering Design provides a potential pathway to address not only the Skills Gap but also the transfer of information from SMEs to a new generation of engineers. Automation has been at the heart of the Advanced Manufacturing Industry, and has been successful at accomplishing repetitive tasks with processes, software and equipment. The next stage in Advanced Manufacturing is further integrating Machine Learning techniques (Artificial Intelligence (AI)) in order to mimic human decision making. These initiatives are clear for the type of mechanized systems and repetitive processes present in the manufacturing world, but the question remains if they can be effectively applied to the decision heavy area of ME Design. A collaboration with an industry partner New Jersey Precision Technologies (NJPT) was established in order to address this question. This thesis presents an ME Design Automation process involving a multi-stage approach: Design Definition, Task Differentiation, Workflow Generation and Expert System Development. This process was executed on plastic extrusion tooling design. A Computer Aided Design (CAD) based Expert System was developed for the Automation of design, and the generation of a database towards future Machine Learning work. This system was run on 6 extrusion product examples previously designed by NJPT through traditional methods. The time needed to generate the design was reduced by 95-98%. This thesis demonstrates the capability of automating ME design, the potential impact in industry and next steps towards the application of AI

Automated design of customized implants

Este artículo muestra un modelo que se postula como capaz para el diseño de un implante craneal personalizado directamente desde el proceso de toma de imágenes médica. La salida de este proceso de diseño se conseguirá en un formato capaz de ser reconocido por el sistema de manufactura. El sistema propuesto se ha creado a partir de la unión de dos prototipos informáticos desarrollados durante la presente investigación, y a través del estudio de las tecnologías relacionadas o circundantes. El núcleo del modelo en la tecnología basada en el conocimiento (KBS), que debe permitir de almacenar y gestionar datos médicos y de diseño para poder aplicar dichos conocimientos durante el proceso de diseño del implante. El objeto de este proyecto es el de obtener una herramienta para mejorar el proceso de diseño, la biocompatibilidad con el paciente y reducir los costes finales, y que pueda ser operado sin necesidad del conocimiento completo de todas sus fases por el usuario.This paper presents a model capable of design a customized cranial implant directly from a medical imaging process, whose output will be a file in a manufacture system recognizable format. The proposed system has been created by linking two computer prototypes developed during the present research and studying the inner and outer related technologies. The core of the model is the KBS (Knowledge Based System) technology, able to store and manage medical data, as well as designer knowledge, in order to use this information in the implant design process. The aim of this project is to obtain a tool to improve the design process, the biocompatibility with patient and reduce final costs, which can be operated without necessity of wide knowledge from the user

Design Concepts for Automating Maintenance Instructions

This research task was performed under the Technology for Readiness and Sustainment (TRS) contract (F33615-99-D-6001) for the Air Force Research Laboratory (AFRL), Sustainment Logistics Branch (HESS) at Wright-Patterson AFB, OH. The period of performance spanned one year starting 29 January 1999. The objective of this task was to develop and demonstrate a framework that can support the automated validation and verification of aircraft maintenance Technical Orders (TOs). The research team examined all stages ofTO generation to determine which tasks most warranted further research. From that investigation, validation and verification of appropriate, safe, and correct procedure steps emerged as the primary research target. This process would be based on available computer-aided design (CAD) data, procedure step ordering from existing sources, and human models. This determination was based on which tasks could yield the greatest impact on the authoring process and offer the greatest potential economic benefits. The team then developed a research roadmap and outlined specific technologies to be addressed in possible subsequent Air Force research tasks. To focus on the potential technology integration of the validation and verification component into existing or future TO generation procedures, we defined a demonstration scenario. Using the Front Uplock Hook assembly from an F/A-18 as the subject, we examined task procedure steps and failures that could be exposed by automated validation tools. These included hazards to personnel, damage to equipment, and incorrect disassembly order. Using the Parameterized Action Representation (PAR) developed on previous projects for actions and equipment behaviors, we characterized procedure steps and their positive and negative consequences. Finally, we illustrated a hypothetical user interface extension to a typical Interactive Electronic Technical Manual (IETM) authoring system to demonstrate how this process might appear to the TO author

Using a Smart Recognition Framework for the Automated Transfer of Structural Whole Engine Models

The development of adequate simulation models from geometric CAD assemblies is one of the most important tasks in early design phases. With this step requiring a lot of manual effort, the desire for a process efficiency improvement via an automated solution rises. In order to derive information about the assembly to build Finite-Element (FE) models, various different steps have to be taken which require visual assessment and engineering evaluation, knowledge and judgement. The approach described in this research mimics the engineer's logic and way of thinking to automate these steps. Thereof, the recognition of entities plays a fundamental role for further processing. To achieve the desired recognition, methods have been developed to retrieve criteria like form, function, context and positioning from the available geometry data. The developed recognition framework supports and provides a component categorization so that specifically optimized process chains for each category can be implemented, depicting a more robust and reasonable overall process

Template-based geometric transformations of a functionally enriched DMU into FE assembly models

International audiencePre-processing of CAD models derived from Digital Mock-Ups (DMUs) into finite element (FE) models is usually completed after many tedious tasks of model preparation and shape transformations. It is highly valuable for simulation engineers to automate time-consuming sequences of assembly preparation processes. Here, it is proposed to use an enriched DMU with geometric interfaces between components (contacts and interferences) and functional properties. Then, the key concept of template-based transformation can connect to assembly functions to locate consistent sets of components in the DMU. Subsequently, sets of shape transformations feed the template content to adapt components to FE requirements. To precisely monitor the friction areas and the mesh around bolts, the template creates sub-domains into their tightened components and preserves the consistency of geometric interfaces for the mesh generation purposes. From a user-selected assembly function, the method is able to robustly identify, locate and transform groups of components while preserving the consistency of the assembly needed for FE models. To enlarge the scope of the template in the assembly function taxonomy, it is shown how the concept of dependent function enforces the geometric and functional consistency of the transformed assembly. To demonstrate the proposed approach, a business oriented prototype processes bolted junctions of aeronautical structures

Pyörivien sähkökoneiden automatisoitu kolmiulotteinen roottoridynaaminen simulointi

Electric motors and generators are utilized widely in industrial applications. The design process of these rotating electrical machines often requires conducting well-known rotordynamic analyses. They include eigenvalue analyses to estimate the natural frequencies, mode shapes, and critical speeds of the machines to avoid harmful resonances. Conducting these analyses is often a routine process for analysts’, and they can be automated. This frees analysts’ time to solve more challenging tasks and reduces costs. This thesis primarily aimed to create a model generator which generates three-dimensional models and finite element meshes of rotating electrical machine rotors based on product data. Furthermore, the aim was integration of the model generator with an analysis software to automate the whole model generation and eigenvalue analysis process. To gain an understanding of the topic, this thesis reviews the advantages and difficulties of integrating geometry modeling, mesh generation and analysis as well as the basic theory of rotordynamic analysis. Furthermore, substructuring is presented as a method to increase flexibility and reduce computation time. As a result of this thesis, a model generator was created and integrated with an analysis software. Two of the generated models were validated by comparing them to reference models. The natural frequencies were then calculated with these models and compared to experimentally measured values of the corresponding rotors. The first four free rotor natural frequencies were predicted with satisfactory accuracy, and the first critical speed was calculated with good accuracy. When compared to manual modeling and analysis work, the total time required to obtain free rotor natural frequencies and mode shapes was reduced to approximately one tenth. Further development of the created modeling and analysis system is recommended based on the results of this thesis.Sähkömoottoreita ja -generaattoreita käytetään useissa teollisissa sovelluskohteissa. Usein näiden pyörivien sähkökoneiden suunnitteluprosessin aikana suoritetaan hyvin tunnettuja roottoridynaamisia analyyseja. Näihin sisältyy ominaisarvoanalyysejä koneiden ominaistaajuuksien, ominaismuotojen ja kriittisten pyörimisnopeuksien arvioimiseen haitallisten resonanssien välttämiseksi. Kyseisten analyysien suorittaminen on usein rutiininomainen prosessi asiantuntijoille ja ne voidaankin automatisoida. Näin voidaan vapauttaa asiantuntijoiden aikaa vaativampien ongelmien ratkaisemiseen ja säästää kustannuksissa. Tämän diplomityön ensisijainen tavoite oli luoda pyörivien sähkökoneiden roottoreiden kolmiulotteisia malleja ja elementtiverkkoja tuottava malligeneraattori, joka toimii tuotetiedon pohjalta. Tavoitteena oli lisäksi integroida malligeneraattori toimimaan laskentaohjelmiston kanssa koko mallinnus- ja ominaisarvoanalyysiprosessin automatisoimiseksi. Työn teoriaosassa esitellään mallien luomisen, verkotuksen ja analyysien integroimisen hyötyjä ja esteitä sekä roottoridynaamisen analyysin taustateoriaa aihepiirin ymmärtämisen tueksi. Lisäksi alirakennetekniikka esitetään menetelmänä laskenta-ajan lyhentämiseen ja joustavuuden lisäämiseen. Työn tuloksena luotiin automaattinen malligeneraattori, joka integroitiin toimimaan laskentaohjelmiston kanssa. Kaksi generoitua mallia validoitiin vertaamalla niitä referenssimalleihin. Näillä malleilla laskettuja ominaisarvoja verrattiin vastaavien roottoreiden kokeellisesti mitattuihin ominaisarvoihin. Ensimmäiset neljä vapaan roottorin ominaistaajuutta pystyttiin ennustamaan tyydyttävällä tarkkuudella ja ensimmäinen kriittinen pyörimisnopeus hyvällä tarkkuudella. Tarvittava kokonaisaika vapaan roottorin ominaistaajuuksien ja -muotojen selvittämiseen väheni noin kymmenesosaan kun verrataan manuaaliseen mallinnus- ja analyysityöhön. Työn tulosten perusteella voidaan suositella luodun mallinnus- ja laskentasysteemin jatkokehitystä

Reason Maintenance in Product Modelling via Open Source CAD System

The present and future challenges of a new product design, forecasting and risk management launch strategy for a new product modelling decision process. This paper intends to propose and to look towards the development of a low-cost integrated CAD-CAPP-CAD/CAM product modelling system for the design and manufacture of a proposed product. It is a mapping between several design phases like functional design, technical design and physical design. The modelling data generation process begins with the drafting of a product to be maintained using the drafting software package. From the CAD drawing, the data are transferred to be used as the product models and a CAPP software package will then prepare the operational parameters for the manufacturing of the product. These process data are relayed to a CAM software package, which will then generate the automating information processing functions. The final stage of the function is to support design and manufacturing operations that may have reaped many benefits in terms of its initial equipment and software costs