RAPID prototyping, NEW product development, MANUFACTURING processes, CONCURRENT engineering, MATHEMATICAL programming, and COMPUTER-aided design

In the "Project GEMA" geometry and mathematics, 62 prototypes were created to establish a conceptual and formal language of the internal architecture of the solids that maintains a progressive continuity through mathematics, to explore and analyze the changes generated by the points, lines, planes and volume of the cube, the sphere and the tetrahedron. The idea of this project came from mixture of geometric graphics and mathematics to construct models in three dimensions using CAD applications and rapid prototyping through the resources and elements of descriptive geometry. This paper illustrates step by step the construction of the "Project GEMA"® cube # 022, from the standpoint of mathematics and design with CAD applications. [ABSTRACT FROM AUTHOR]

RAPID prototyping, SIMULATION methods & models, COMPUTER software, COMPUTER-aided design, COMPUTER simulation, DENTAL implants, and TOMOGRAPHY

The dental implant surgery results usually depend on dentists' clinical experiences and judgments. Most implant surgery utilizes the software to process pre-operation planning and simulation. Hence, this research intended to apply the rapid prototyping (RP) technique to build real mandible model for implant surgery simulation. Unlike other simple mandible RP models, vessels and nerves pathways are demonstrated in our model to help dentists to avoid false drillings on them. Besides, orientation pillars for surgical guide are included in the model. Moreover, for comparison's purpose, the platforms of placing indexing balls are also integrated. Computed tomography (CT) data of mandible were first converted to a CAD model with vessels, nerve, orientation pillars, and indexing platforms by a medical imaging processing software. RP technique was then utilized to obtain a real 3D model for pre-operation planning, surgical guide fabrication, and surgery simulation. The mandible model helped to drill holes on the traditional surgical guide by a 5-axis CNC drill press and it also drilled into the mandible model. Besides, the dentist simulated the drilling process in the dental implant surgery on the mandible model. Both drilled RP mandible models were CT-scanned and compared with the designed implant locations and angles. The errors are within acceptable region. Our approach has been successfully demonstrated in dental implant's pre-operation planning and simulation, which will help to increase the successful rate and safety of dental implant surgery. [ABSTRACT FROM AUTHOR]

RAPID prototyping, COMPUTER software, COMPUTER-aided design, COMPUTER simulation, KINEMATICS, MOTION, and AUTOMOBILE racing

This paper addresses the issue of creating physical prototypes of large-scale and complex assemblies using Rapid Prototyping technology. There are several technical challenges to overcome, both in software and the physical models. The challenges in software mainly stem from the fact that the mainstream CAD systems may not able to directly convert large-scale and complex assemblies to STL models. For the issues in the physical model, some of the components of the scaled assemblies are too small to fabricate using RP or too weak to produce viable prototypes for intended purposes. In addition, the paper presents information regarding support of relative motion between components in the RP model, which is desirable for demonstrating kinematics of the system. The paper proposes a systematic approach that addresses these issues and realizes quality physical prototypes serving intended purposes. Practical examples are employed in this paper, including a Formula SAE race car assembly that is used as the principle example for this study. [ABSTRACT FROM AUTHOR]

RAPID prototyping, COMPUTER-aided design, MATHEMATICAL models, BIOREACTORS, LIVER cells, BIOENGINEERING, and CELL culture

A fiber in fiber (FIF) bioreactor was designed and developed for cell culture to become a bioartificial liver device. The design consists of a conventional hollow fiber cartridge as a cell culture system with the addition of a second set of hollow fibers places within the lumens of the primary set. This arrangement provides three discrete spaces (compartments). A 3D CAD model of the device was developed and used to provide the suitable arrangement of these compartments. Internal and external diameters of the commercially available hollow fibers were studied and chosen. Two configurations of the device were developed and tested. Based on a 3D CAD model, two modules of the device were constructed and studied. Experimental evaluation of small scale FIF improved device prototype were constructed and results from studied quality assurance are also presented. The results showed that the developed bioartificial liver device has an excellent oxygen transfer rate which can improve the achievement of high density cell culture. [ABSTRACT FROM AUTHOR]

RAPID prototyping, PROTOTYPES, COMPUTER-aided design, CONCURRENT engineering, and MANUFACTURING processes

In contrast to traditional rapid prototyping of homogeneous objects, fabrication of heterogeneous objects (using layered manufacturing technologies) requires additional material information to be incorporated along with the object's geometries. The paper presents relevant data structures and algorithms for virtual prototyping of heterogeneous objects. Heterogeneous CAD models, which represent the ideal digital heterogeneous objects, are first described. Interrogation of the material compositions from the CAD models is then carried out at runtime. Voxels (with location-specific material properties) are subsequently created and maintained in a dynamic scan-line structure, layered-section structure and the virtual-object structure. The proposed data structures and the associate algorithms have been successfully applied in virtually prototyping of heterogeneous objects. Virtually fabricated heterogeneous object examples are provided. [ABSTRACT FROM AUTHOR]

RAPID prototyping, MANUFACTURING processes, MANUFACTURES, NEW product development, CONCURRENT engineering, JOB analysis, PROTOTYPES, TIME to market (New products), and ECONOMIC trends

This paper discusses the current status of layer-based manufacturing Rapid Prototyping (RP) technology and how it is being successfully implemented as a tool for product development (PD). A brief introduction to RP is given, focusing on the limitations of existing technology. Future trends for RP development are then discussed with further consideration for software issues in future applications. [ABSTRACT FROM AUTHOR]

COMPUTER-aided design, RAPID prototyping, PROTOTYPES, CONCURRENT engineering, MANUFACTURING processes, JEWELRY making, FASHION design, and RAPID tooling

This paper presents the investigation of computer-aided design and rapid prototyping technologies in jewelry design and manufacturing. Computer-aided design (CAD) and Rapid prototyping (RP) technologies play important roles in many industries including the jewelry industry. In this paper, CAD and RP technology is applied to design and build jewelry prototypes, and Rapid Tooling to build molds. The main aim of this paper is to describe the implementation of CAD and RP processes in the jewelry design and manufacturing. The applicability and effectiveness of RP, using Stereolithography Apparatus (SLA), is investigated in the field of jewelry model and mold making, moreover, the methodology is compared to conventional methods in term of time requiring, quality and manufacturing factors. [ABSTRACT FROM AUTHOR]

COMPUTER integrated manufacturing systems, COMPUTER-aided design, RAPID prototyping, COMPUTER-aided engineering, PROCESS control systems, and COMPUTER-generated imagery

The rapid physical realization of a product from a CAD model prior to full scale manufacturing presents a challenging task for industrial companies, as well as academic researchers. This paper presents a rapid and flexible prototyping system designed to directly connect a CAD system (Alias) with a software based DMAC (Direct Machining And Control) controller. The overall architecture is presented and the tool path planning, animation, and direct machining under Alias are explained. The implementation of the proposed prototyping system is realized on a three-axis mill. An example of milling a real surface through this direct CNC system is presented and conclusions are drawn. [ABSTRACT FROM AUTHOR]

CAD/CAM systems, RAPID prototyping, GEOMETRIC modeling, COMPUTER graphics, REVERSE engineering, and CURVE rectification & quadrature

Recently point set model is getting increasing research attention in many geometric modeling application areas including computer graphics and CAD/CAM. This paper presents a novel approach to directly slicing point set model with the focus on making rapid prototyping part out of point set model without making any mesh or surface. Main challenge in handling point set model lies in how to interpret inter-point empty space and implicit quadric surfel is used in this research. This paper also explains how to utilize the quadric surfel for slicing the point set, so as to obtain contour curves for RP. Also described in this paper is how to extract smooth curve(s) out of the 2D point cloud obtained by slicing the 3D point set model. [ABSTRACT FROM AUTHOR]

RAPID prototyping, APPLICATION software, UNCERTAINTY (Information theory), FEASIBILITY studies, WINDOWS (Graphical user interfaces), SOFTWARE architecture, and MICROFABRICATION

This study developed an easily-used system for designing a transtibial socket that will be fabricated by a rapid prototyping (RP) machine. This proposed system is to improve the quality of uncertainty of plaster-based process of fabricating the transtibial socket. In this study, the concept of total surface bearing (TSB) is employed to obtain stump model of an amputee under appropriate pressure. Using TSB stump model, editing complex surface can be avoided, and the quality of sockets can be improved by the simplified design process. In the plaster-based production process, the plaster stump mold must be destroyed in order to fabricate a prosthetic socket. If a socket should be reproduced, it will be difficult to clearly point out the difference between the previous and the new stump molds. If a proper CAD system can be used, the difficulty of reproducing a socket will be easily resolved. Currently, manufacturing RP sockets is not an important issue as a convenient RP service bureau already exists. The lack of an appropriate system for designing transtibial sockets is the major barrier. The development of an easily-used transtibial socket design system is required. To demonstrate the feasibility of this proposed system, two case studies including a resin-reinforced RP transtibial socket and an RP stump mold for replacing the plaster mold used in plaster-based method were designed and fabricated for a volunteer amputee. The motion analysis and trial use of the prosthetic sockets verified the applicability of this prototype CAD system. Recruiting more amputees to examine and validate this developing system is being arranged. [ABSTRACT FROM AUTHOR]

PROTOTYPES, COMPUTER-aided design, COMPUTER software, GEOMETRY, and ENGINEERING models

Improvement of part surface quality and geometric accuracy by modifying slicing procedure in RP has been a major concern. Reduction in build time and enhancement of part surface quality are two factors which contradict with each other as decreasing build time detracts part quality because of staircase effect. There have been a number of attempts to tackle this problem by using adaptive slicing procedures in which slice thickness is determined by the local part geometry and RP machine specifications. A geometrical parameter known as cusp height is limited to a pre-specified value in various existing adaptive slicing procedures, which is defined for rectangular or sloping edge profiles only. In another approach, relative change in areas of successive slices have been considered as criterion to adaptively slice CAD models but this method has limitation as local geometry of part is not taken into consideration. Therefore, in the present work, a slicing procedure is presented in which statistical surface roughness model developed by Pandey and his group [1] for SLS prototypes has been used as a key to slice the tessellated CAD model adaptively. The adaptive slicing system is implemented as Graphic User Interface in MATLAB-7. The capabilities of developed adaptive slicing system have been demonstrated by case studies. [ABSTRACT FROM AUTHOR]

ALGORITHMS, MANUFACTURES, ENGINEERING, MANUFACTURING processes, NEW product development, BIOMEDICAL engineering, COMPUTER simulation, and VIRTUAL reality

This paper proposes a multi-material virtual prototyping (MMVP) system that integrates the virtual reality (VR) and the layered manufacturing (LM) technologies for digital fabrication of heterogeneous multi-material prototypes for advanced product development and biomedical engineering. The system consists mainly of two algorithms for sequential and concurrent multi-toolpath planning, and a virtual prototyping system. The algorithms adopt a topological hierarchy-sorting algorithm to establish the hierarchy relationship of multi-material slice contours for facilitating toolpath planning of multi-material layered manufacturing (MMLM). Subsequently, the sequential multi-toolpath planning algorithm generates sequential toolpaths that avoid redundant tool movements. To reduce build time further, the concurrent multi-toolpath planning algorithm generates collision-free concurrent toolpaths. Based on the hierarchy information, a bounding box can be adopted to approximate envelopes of contour families of the same material property to simplify detection of tool collisions. The algorithms are integrated to form the MMVP system for planning, stereoscopic simulation, and validation of multi-toolpaths for MMLM. [ABSTRACT FROM AUTHOR]

PROTOTYPES, MANUFACTURING processes, VIRTUAL reality, COMPUTER simulation, and STEREOSCOPIC views

This paper proposes a CAVE-based multi-material virtual prototyping (CMMVP) system for immersive stereoscopic visualisation and optimisation of multi-material layered manufacturing (MMLM) processes. The CMMVP system consists mainly of a suite of software packages for simulation of MMLM processes, integrated with a multi-screen CAVE-based virtual reality (VR) system, to create an immersive virtual environment for digital fabrication of multi-material product prototypes. In comparison with desktop-based or semi-immersive VR systems, the CMMVP system blocks out environmental disturbances such that designers can fully immerse in performing stereoscopic visualisation and quality analysis of the resulting multi-material prototypes for subsequent improvements of a product design. The CMMVP system facilitates advanced product design and helps reduce product development time and cost substantially. [ABSTRACT FROM AUTHOR]

CLOTHING industry, PROTOTYPES, CLOTHING & dress, COMPUTER simulation, and OPTIMAL designs (Statistics)

Despite numerous methods available for cloth simulation, virtual garment prototyping has yet to find its way toward the garment industry, the main issues being simulation accuracy and the potentiality for reproducing the complex behavior of complex garment models. These goals can only be reached through an optimal combination of modeling techniques and numerical methods that combines high computation efficiency with the versatility required for simulating intricate garment designs. We here describe optimal choices illustrated by their integration in a design and simulation tool that allow interactive prototyping of garments along drape motion and comfortability tests on animated postures. [ABSTRACT FROM AUTHOR]

RAPID prototyping, INVESTMENT casting, CASTING (Manufacturing process), INJECTION molding, COMPUTER simulation, and HEAT transfer

This paper presents a study of replacing, in the domain of wax injection molding process, the traditional metallic mold with a mold made of a RP plastic material combined with a PCM material. The process being studied here uses melted paraffin wax as the injection material. Numerical simulation of transient heat transfer was conducted with COMSOL multi-physics software. The behavior of the melting and heat absorption of PCM was simulated by modifying the specific heat of the material to account for the increased amount of energy in the form of latent heat of fusion over its melting temperature range. ABS plastic mold was made through FDM Rapid Prototyping process and a carefully prepared experiment was successfully conducted. To confirm the validity of the numerical simulation, the data acquired during the experiment was compared with the numerical results and the outcome was satisfactory. [ABSTRACT FROM AUTHOR]

COMPUTER-aided design, RAPID prototyping, COMPUTER-aided engineering, GEOMETRIC modeling, and COMPUTER simulation

The role of computers and of computer-aided design tools for the creation geometrical shapes that will be judged primarily by aesthetic considerations is reviewed. Examples are the procedural generation of abstract geometrical sculpture or the shape optimization of constraint curves and surfaces with some global "cost" functional. Different possibilities for such "beauty functionals" are discussed. Moreover, rapid prototyping tools based on layered manufacturing now add a new dimension to the visualization of emerging designs. Finally, true interactivity of the CAD tools allows a more effective exploration of larger parts of the design space and can thereby result in an actual amplification of the creative process. [ABSTRACT FROM AUTHOR]

COMPUTER-aided design, COMPUTER-aided engineering, TEXTILE design, COMPUTER graphics, COMPUTER simulation, and INDUSTRIAL textiles

Virtual prototyping of cloth has recently become a topic of increasing interest both in computer graphics and computer-aided design for industrial fabric or apparel production. Aiming at an accurate simulation of garment shapes, this paper presents a physics-based system for virtual cloth modelling, specifically conceived for design purposes and targeted to the clothing industry. This environment should allow the designer/modellist to validate her/his style and design options through the analysis of garment virtual prototypes and simulation results in order to reduce the number and role of physical prototypes. To this end, a complete physics-based model has been defined, oriented to actual complex-shaped apparel, incorporating aspects related to garment's shape and structure (e.g., 2D profiles of basic patterns and multi-layered parts), mechanical/structural properties of fabric materials and multi-layered parts, and design/manufacturing processes (e.g., ironing, starching). The physical garment's model has been developed upon a particle-based model embedded in constrained Newtonian dynamics with collision management. The system has been validated within European and national projects, simulating several female and male garments with different levels of design complexities and directly provided from involved clothing companies. [ABSTRACT FROM AUTHOR]

RAPID prototyping, MATHEMATICAL models, FEASIBILITY studies, MATHEMATICAL optimization, CONSTRAINTS (Physics), and MECHANICAL behavior of materials

Toolpath planning is vital to multi-material layered manufacturing (MMLM), particularly for improvements in fabrication efficiency and quality of prototypes. This paper proposes a toolpath design platform (TDP) for planning and validation of toolpaths in MMLM. The TDP consists of three constraint modelling modules to represent common operational and mechanical constraints of an MMLM process, and subsequently generate feasible and efficient toolpaths for digital fabrication of multi-material prototypes in a built-in virtual prototyping (VP) module. The material deposition speeds and priorities can also be adjusted to suit various material properties and optimize the toolpaths. Simulations show that the TDP is an effective tool to model and simulate MMLM processes, and accordingly generate practicable toolpath strategies for different application requirements. [ABSTRACT FROM AUTHOR]

ALGORITHMS, COMPUTER-aided design, SIMULATION methods & models, VOLUMETRIC analysis, and SURFACES (Geometry)

In this paper, detailed algorithms are presented for eliminating inconsistency in a tri-dexel volumetric models and reconstructing a water-tight polyhedral surface model from the tri-dexel volumetric model. By using the surface normal information saved in each dexel grid node, a refinement process is applied to reconstructing sharp edges and apex vertices in polyhedral surface models. The advantage of tri-dexel model is its balance in modeling accuracy and memory consumption. It is a challenge problem to convert it to a water-tight polyhedral surface model for downstream applications. The proposed techniques can be used as a geometric representation kernel in Computer-Aided Design and Manufacturing (CAD/CAM) and Computer Numerically-Controlled process simulation systems. [ABSTRACT FROM AUTHOR]

RAPID prototyping, MANUFACTURING processes, GEOMETRIC modeling, PIXELS, NUMERICAL analysis, and EXPERIMENTAL design

Slicing contour generation for geometric model is a vital process in rapid prototyping manufacturing. When slicing a heterogeneous object (HO), we take into account not only the geometric slicing but also the gradient material information. In this paper, we develop a new method to slice a heterogeneous object where the geometric contours are taken as constraints to resample the heterogeneous information through pixel overlap interpolation and tri-linear interpolation, which can maintain the original heterogeneous material information as much as possible and the slicing boundary as accurate as possible. The novelty of our method is that the gradient material resampling with geometry constraint can guarantee the crisp boundary of the HO slices when the gradient information is converted for geometric space to image space. Experimental results validate that our method can create heterogeneous object slices with more accurate boundary than simple interpolation scheme. [ABSTRACT FROM AUTHOR]