Computer Assisted Design and Structural Topology Optimization of Customized Craniofacial Implants

Author(s):  
Carlos A. Gómez Pérez ◽  
Hugo I. Medellín-Castillo ◽  
Raquel Espinosa-Castañeda

Modern design and manufacturing engineering technologies have greatly improved the way in which modern craniofacial implants are designed and fabricated. However, few efforts have been made in order to optimize their design. While the weight of polymer-based implants (e.g. PMMA implants) may not affect the patient’s comfort, the higher weight of metal-based implants (e.g. titanium implants), could greatly affect the patient’s comfort, causing in some cases nuisances and imbalance problems. Thus, the optimization of the implant becomes relevant in order to guarantee its structural stiffness but with a reduced weight. In this paper, the design and structural optimization of customized craniofacial implants based on the use of modern engineering technologies is presented. The aim is to introduce an engineering methodology for the design and optimization of customized craniofacial implants. The methodology starts from the patient’s medical images, obtained from a computerized tomography (CT), which are processed to reconstruct the digital 3D model. Next, the geometrical design of the implant is carried out in a computer aided design (CAD) system using the patient’s 3D model. Then, the structural analysis of the implant is performed using the Finite Element Method (FEM) and considering a quasi-static load. The topology optimization of the implant is made using the Solid Isotropic Material Penalization (SIMP) method. Finally, the optimized customized implant is fabricated in an additive manufacturing (AM) system. A case study of a craniofacial implant is presented and the results reveal that the proposed methodology is an effective approach to design and optimize craniofacial implants.

Author(s):  
Saurabh Srivastava ◽  
Sachin Salunkhe ◽  
Sarang Pande ◽  
Bhavin Kapadiya

Steering knuckle connects steering system, suspension system and braking system to the chassis. The steering knuckle contributes a significant weight to the total weight of a vehicle. Increasing the efficiency of an automobile without compromising the performances is the major challenge faced by the manufacturers. This paper presents an effective topology optimization of steering knuckle used in a vehicle with the primary objective of minimizing weight. The study on optimization of knuckle is divided into two phases, the first phase involves making of a computer-aided design model of the original steering knuckle and carry out finite element analysis on the knuckle by estimating the loads, which are acting on the component. In the second phase, design optimization of the model of steering knuckle is carried out, and excess material is removed at the region where induced stress is negligible as obtained in finite element analysis assuming standard boundary and loading conditions. The paper describes a research work carried out to optimize structural topology giving the essential details. The methodology may be applied to optimize structural components used in applications where the ratio of desired properties to the cost, generally in terms of weight, is to be optimized. In the case of automobiles, strength to weight ratio has to be maximized. New researchers working in the area will have an understanding of the procedures, and further, the techniques may be applied to design in general.


Author(s):  
E.V. Belov ◽  
E.A. Brusin

In this paper we propose the design of the receiving path of an advanced satellite modem. The receiver comprises only the components produced by Russian domestic companies. The parameters of the receiver are discussed in the paper. 3D model of the receiver board obtained using the Altium Designer integrated computer-aided design (CAD) system is also presented.


VCOT Open ◽  
2018 ◽  
Vol 01 (01) ◽  
pp. e12-e18
Author(s):  
Griselda Lam ◽  
Sun-Young Kim

Objective The main purpose of this study was to describe the use and benefits of 3-dimensional (3D) computer-assisted surgical planning (CASP) and printing in a complex articular fracture repair in a dog. Study Design Case report. Animals Client-owned dog. Results One dog with a closed, severely comminuted, distal femoral supracondylar and bicondylar fracture underwent a preoperative computed tomography scan. Three-dimensional CASP was performed using computer-aided design software. Three-dimensional CASP allowed for visualization of the fracture fragments and virtual surgery, including reduction of the fragments and implant placement. A 3D model of the affected femur was printed and a bone plate was pre-contoured to the model. Intraoperative fracture reduction and stabilization were performed without complications. Postoperative radiographs revealed successful execution of the planned procedure. Subsequent radiographs and clinical examination indicated that bone healing was achieved with return to normal function of the limb. Three-dimensional CASP and the printed 3D model allowed for improved understanding of the anatomical relationship between fracture fragments, preoperative implant selection and contouring, and the ability to practice fracture reduction and implant placement preoperatively. The model was also used for client education, and to teach students and residents. Conclusion Three-dimensional CASP and printed models are valuable tools in the preoperative planning of complex fracture repairs, educating clients and teaching students and residents.


Author(s):  
J F T Pittman

A review is provided of issues and techniques in design and optimization of profile extrusion dies for thermoplastics and rubber, with particular emphasis on unplasticized polyvinyl chloride and rubber compounds. Traditional profile die design methods are contrasted with computer-based ones, with respect to efficiency and economic benefits. The main types of die construction are outlined. Physical phenomena relevant to the design and performance of dies are summarized, including: rheology and kinematics of the flow, wall slip, extrusion instabilities, residence time and degradation, extrudate swell, draw-down, and thermal effects. Approaches and strategies for die design are explained, including: flow balancing – with guidance from analytic flow results, the Avoid-Cross-Flow strategy, use of flow separators, and designing for extrudate swell. Published computer simulations of die flow used to assist with design are reviewed. Introducing automatic die design, the structure and elements of a computerized design optimization environment are set out. Key components and options within this are described, including: objective functions, constraints, design variables, optimization algorithms, design parameterization and flow domain meshing, and optimization strategies. Published implementations of computerized profile die design optimization are described. Automatic design optimization is compared with the work of a designer assisted by flow simulations in the industrial environment, showing how substantial reductions in demands on the designer's time are possible. The nature and potential of robust design is outlined, with techniques for its implementation. Conclusions are drawn as to the present state of the art in computer-assisted profile die design and optimization, and potential advances.


Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 181 ◽  
Author(s):  
Dalibor Bartonek ◽  
Michal Buday

This article describes problems that occur when creating three-dimensional (3D) building models. The first problem is geometric accuracy; the next is the quality of visualization of the resulting model. The main cause of this situation is that current Computer-Aided Design (CAD) software does not have sufficient means to precision mapping the measured data of a given object in field. Therefore the process of 3D model creation is mainly a relatively high proportion of manual work when connecting individual points, approximating curves and surfaces, or laying textures on surfaces. In some cases, it is necessary to generalize the model in the CAD system, which degrades the accuracy and quality of field data. The article analyzes these problems and then recommends several variants for their solution. There are described two basic methods: using topological codes in the list of coordinates points and creating new special CAD features while using Python scripts. These problems are demonstrated on examples of 3D models in practice. These are mainly historical buildings in different locations and different designs (brick or wooden structures). These are four sacral buildings in the Czech Republic (CR): the church of saints Johns of Brno-Bystrc, the Church of St. Paraskiva in Blansko, further the Strejc’s Church in Židlochovice, and Church of St. Peter in Alcantara in Karviná city. All of the buildings were geodetically surveyed by terrestrial method while using total station. The 3D model was created in both cases in the program AUTOCAD v. 18 and MicroStation.


2014 ◽  
Vol 574 ◽  
pp. 167-172
Author(s):  
Zhe Zhang ◽  
Ying Chao Zhang ◽  
Jing Mei Jin ◽  
Bo Guo ◽  
Ming Chi ◽  
...  

According to the model devised by the design team of PACE Future Bus and the layout size of pure electric coaches in the market, we used CATIA to make a 3D model and made Topology optimization design by using HyperWorks. After that, we imposed loading according to specific conditions and made structural topology optimization and sized optimization design. Then we checked the coach skeleton beam element model and the strength of shell element model. Finally, the future bus frame was built completely.


2012 ◽  
Author(s):  
Syaimak Abd. Syukur ◽  
Masine Md Tap

Sistem Rapid Prototyping (RP) ialah teknologi yang menukar sesuatu reka bentuk yang dibina dalam Computer Aided Design (CAD) ke suatu komponen model 3D. Model CAD biasanya dibina dalam sistem CAD yang kemudiannya dihantar ke sistem RP. Antaramuka yang baik antara sistem CAD dan sistem RP adalah salah satu faktor penting dalam menghasilkan prototaip yang berkualiti tinggi. Kertas kerja ini melaporkan hasil uji kaji yang dijalankan untuk mengenal pasti masalah-masalah dalam memindahkan data antara satu sistem CAD (UNIGRAPHICS) dan satu sistem RP (QUICKSLICE). Berdasarkan hasil uji kaji dan analisis yang dijalankan, satu garis panduan dicadangkan untuk perpindahan data yang lebih berkesan antara sistem CAD (UNIGRAPHICS) dan sistem RP (QUICKSLICE). Kata kunci: CAD; CAM; CAD/CAM; Rapid Prototyping Rapid Prototyping (RP) is a technology that transform a design generated in Computer Aided Design (CAD) to a 3D model parts. CAD models are usually done on a CAD system and then transported into the RP system. A good interface between the CAD and the RP system is one of the key factors of producing a good quality prototype. This paper reports on the results of an experimentation carried out to identify the problems in transferring data between a CAD system (UNIGRAPHICS) and an RP system (QUICKSLICE). Based on the experimentation’s results and analysis, a basic guideline is proposed for a safer data transfer between the CAD system (UNIGRAPHICS) and an RP system (QUICKSLICE). Key words: CAD; CAM; CAD/CAM; Rapid Prototyping


2006 ◽  
Vol 116-117 ◽  
pp. 669-672
Author(s):  
Man Sig Kim ◽  
Eui Yeol Lee

Current practice in designing tooling components for semisolid processing requires extensive commitments of human resources. Even when utilizing currently available Computer Aided Design (CAD) systems, tool design remains a complex task requiring large amount of design knowledge. Considerations such as part material, tool material, characteristics of die filling, flow behavior of semisolid slurries must be carefully thought by the tool designer to reach an acceptable tooling solution. This paper proposes the framework for computer assisted tool design by integrating tool design domain knowledge into CAD system to help tool designers.


Author(s):  
Z. F. Z. Abidin ◽  
M. N. Osman Zahid

Object customization in Computer Aided Design (CAD) is a method used to modify the sketch parameters and change the model geometries. This method is one of important features in part modelling which empowered CAD user to simply modify their product. The conventional method of modifying CAD model is usually relied on the manual editing. This paper outlines a development of program than can be integrated in CAD/CAM system for real time object customization. It uses Visual Basic (VB) programming with custom Graphical User Interface (GUI) generated in NX10 (CAD/CAM software) interface. The main contribution of this research is a tool for real time object customization that capable to assist the modification of 3D model. In order to develop the tool, 3D model modification instructions are translated into programming codes by using Journaling tools in NX interface. Editable parameters are identified based on the model shapes. The related codes are reconstructed, modified and linked to the functional GUI.  This allows user to simply modify the model shapes in real time with minimum process steps. The performance of the method is evaluated in terms of the reduction of process steps and time in modifying the 3D model in CAD system. All the findings and details of approach are presented.


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