Physical modeling and geometry configuration simulation for flexible cable in a virtual assembly system

2019 ◽  
Vol 40 (6) ◽  
pp. 905-915
Author(s):  
Du Hongwang ◽  
Wei Xiong ◽  
Wang Haitao ◽  
Wang Zuwen
Keyword(s):  
Boundary Conditions ◽  
Computer Aided Design ◽  
Experimental Results ◽  
Content Type ◽  
Flexible Cable ◽  
Computer Aided ◽  
Geometry Configuration ◽  
Cable Assembly ◽  
Configuration Simulation ◽  
Kirchhoff Theory

Purpose In this paper, a novel and unified method for geometry configuration simulation of flexible cable under certain boundary conditions is presented. This methodology can be used to realize cable assembly verification in any computer-aided design/manufacturing system. The modeling method, solution algorithm, geometry configuration simulation and experimental results are presented to prove the feasibility of this proposed methodology. The paper aims to discuss these issues. Design/methodology/approach Considering the gravity, bending and torsion, modeling of cable follows the Kirchhoff theory. For this purpose, Euler quaternions are used to describe its spatial geometry configuration by a carefully chosen set of coordinates. Then the cable is discretized by the FEM, and the equilibrium condition per element is computed. In this way, the global static behavior is independent of the discretization. The static evolution of the cable is obtained by numerical integration of the resulting Kirchhoff equations. Then the manner is demonstrated, in which this system of equations can be decoupled and efficiently solved. Geometry configuration simulation examples with different boundary conditions are presented. Finally, experiment validation are given to describe the effectiveness of the models and algorithms. Findings The method presented in this paper can be adapted to computer-aided assembly verification of flexible cable. The experimental results indicate that both of the model and algorithm are efficient and accurate. Research limitations/implications The method should be extended to flexible cables with multiple branches and more complex constraints (holes, curved surfaces and clamps) and non-circular sections. Dynamic assembly process simulation based on the Kirchhoff theory must be considered in the future. Originality/value Unlike in previous approaches, the cable behavior was independent of the underlying discretization, and the finite element approach enables physically plausible cable assembly verification.

Constraints and limitations of concrete 3D printing in architecture

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chien-Ho Ko
Keyword(s):  
3D Printing ◽  
Manufacturing Process ◽  
Computer Aided Design ◽  
Research Approach ◽  
Layer By Layer ◽  
Content Type ◽  
Improve Design ◽  
Study Results ◽  
Computer Aided ◽  
Property Control

Purpose Additive manufacturing of concrete (AMoC) is an emerging technology for constructing buildings. However, due to the nature of the concrete property and constructing buildings in layers, constraints and limitations are encountered while applying AMoC in architecture. This paper aims to analyze the constraints and limitations that may be encountered while using AMoC in architecture. Design/methodology/approach A descriptive research approach is used to conduct this study. First, basic notions of AMoC are introduced. Then, challenges of AMoC, including hardware, material property, control and design, are addressed. Finally, strategies that may be used to overcome the challenges are discussed. Findings Factors influencing the success of AMoC include hardware, material, control methods, manufacturing process and design. Considering these issues in the early design phase is crucial to achieving a successful computer-aided design (CAD)/computer-aided manufacturing (CAM) integration to bring CAD and CAM benefits into the architecture industry. Originality/value In three-dimensional (3D) printing, objects are constructed layer by layer. Printing results are thus affected by the additive method (such as toolpath) and material properties (such as tensile strength and slump). Although previous studies attempt to improve AMoC, most of them focus on the manufacturing process. However, a successful application of AMoC in architecture needs to consider the possible constraints and limitations of concrete 3D printing. So far, research on the potential challenges of applying AMoC in architecture from a building lifecycle perspective is still limited. The study results of this study could be used to improve design and construction while applying AMoC in architecture.

Parametric geometry model design of a wingsuit

2020 ◽  
Vol 32 (5) ◽  
pp. 691-705
Author(s):  
Nazanin Ansari ◽  
Sybille Krzywinski
Keyword(s):  
Computer Aided Design ◽  
Early Stage ◽  
Three Dimensional ◽  
Production Costs ◽  
Process Chain ◽  
Content Type ◽  
Geometry Model ◽  
Computer Aided ◽  
2D Pattern ◽  
Aided Design

PurposeThis paper aims to introduce a process chain spanning from scanned data to computer-aided engineering and further required simulations up to the subsequent production. This approach has the potential to reduce production costs and accelerate the procedure.Design/methodology/approachA parametric computer-aided design (CAD) model of the flyer wearing a wingsuit is created enabling easy changes in its posture and the wingsuit geometry. The objective is to track the influence of geometry changes in a timely manner for following simulation scenarios.FindingsAt the final stage, the two-dimensional (2D) pattern cuts were derived from the developed three-dimensional (3D) wingsuit, and the results were compared with the conventional ones used in the first stages of the wingsuit development.Originality/valueProposing a virtual development process chain is challenging; apart from the fact that the CAD construction of a wingsuit flyer – in itself posing a complicated task – is required at a very early stage of the procedure.

The current status on 3D scanning and CAD/CAM applications in textile research

2019 ◽  
Vol 32 (6) ◽  
pp. 891-907
Author(s):  
Ivana Špelic
Keyword(s):  
Computer Aided Design ◽  
Textile Industry ◽  
Future Trend ◽  
Current Status ◽  
New Production ◽  
Initial Development ◽  
Content Type ◽  
Computer Aided ◽  
Cad Cam ◽  
Cam Systems

Purpose In order to present a significant usage of the computer-aided design (CAD)/computer-aided manufacturing (CAM) systems in the apparel and textile industry, the current literature has been observed. Although the CAD/CAM systems have also been increasingly applied to all fields apparel and textile manufacturing for the last few decades, improving the precision, productivity and the organization of the information flow, they have not been fully utilized in these industrial fields. The paper aims to discuss these issues. Design/methodology/approach The paper is structured in three main sections showing the vast applicability of the CAD/CAM systems, the benefits provided by them and the future trend in their development. Findings Although the initial development of the CAD/CAM systems strived to completely eliminate manual and time-consuming operations, they have not been accepted in practice due to their inflexibility at making changes and the time needed for regenerating a complex parametric model. The textile and apparel industries show slow progress in acquiring the CAD/CAM systems. Originality/value This CAD/CAM technology enabled the customization in the design process according to individual needs and directed the textile and the apparel industry to moving into new directions such as the mass customization to personalization. The paper makes clear that although this technological concept is rather old, the use of the CAD/CAM systems will inevitably broaden in terms of applicability to new production stages.

Rapid prototyping-assisted fabrication of the customized metatarsophalangeal joint implant (SamKu)

2014 ◽  
Vol 20 (4) ◽  
pp. 270-279 ◽  
Author(s):  
Sameer C. Raghatate ◽  
Abhaykumar M. Kuthe ◽  
Tushar R. Deshmukh ◽  
Sandeep W. Dahake
Keyword(s):  
Rapid Prototyping ◽  
Computer Aided Design ◽  
Surgical Planning ◽  
Metatarsophalangeal Joint ◽  
Content Type ◽  
Advanced Technologies ◽  
Joint Implant ◽  
Computer Aided ◽  
Aided Design ◽  
Practical Implications

Purpose – The main purpose of this paper is to report the successful treatment modality for patients suffering from arthritis of the metatarsophalangeal joint (MTPJ) of the foot which otherwise could not be treated through traditional surgeries. Design/methodology/approach – The unique capabilities of the computer-aided design and the rapid prototyping (RP) technology are used to develop the customized MTPJ implant (SamKu). Findings – This approach shows good results in the fabrication of the MTPJ implant. Postoperatively, the patient experienced normalcy in the movement of the MTPJ of the foot. Practical implications – Advanced technologies made it possible to fabricate the customized MTPJ implant (SamKu). The advantage of this approach is that the physical RP model assisted in designing the final metallic implant. It also helped in the surgical planning and the rehearsals. Originality/value – This case report illustrates the benefits of imaging/computer-aided manufacturing/RP to develop the customized implant and serve those patients who could not be treated in the traditional way. This is a pioneered attempt toward implementation of a customized implant for patients suffering from arthritis of the MTPJ.

CONSTRUCTING SURFACE FEATURES THROUGH DEFORMATION

2010 ◽  
Vol 10 (01) ◽  
pp. 41-56
Author(s):  
XIAOPING WANG ◽  
SHENGLAN LIU ◽  
LIYAN ZHANG
Keyword(s):  
Computer Graphics ◽  
Computer Aided Design ◽  
Mechanical Design ◽  
Computational Cost ◽  
Experimental Results ◽  
Mathematical Approach ◽  
Computer Aided ◽  
Aided Design ◽  
Low Computational Cost ◽  
Frequent Problem

A frequent problem in computer aided mechanical design is the construction of arbitrarily-shaped ribs and beads on surfaces, to increase their rigidity or for aesthetic reasons. We improve upon a previous mathematical approach for defining such ribs and beads, based on using so-called extension functions to define a deformation matrix, which is then applied to the underlying shape. Our improvements offer important practical advantages: firstly, by use of cosine extension functions, we get a greater control over, and flexibility of, rib shape, including the possibility of repeating ribs; secondly, we can directly control the spine curves. We give experimental results to demonstrate that the method is simple and intuitive, has low computational cost, and is potentially useful for computer aided design, computer graphics and other applications.

Personalized femoral component design and its direct manufacturing by selective laser melting

2016 ◽  
Vol 22 (2) ◽  
pp. 330-337 ◽  
Author(s):  
Changhui Song ◽  
Yongqiang Yang ◽  
Yunda Wang ◽  
Jia-kuo Yu ◽  
Di Wang
Keyword(s):  
Corrosion Resistance ◽  
Selective Laser Melting ◽  
Femoral Component ◽  
Computer Aided Design ◽  
Design Method ◽  
Laser Melting ◽  
Content Type ◽  
Computer Aided ◽  
Biological Corrosion ◽  
Aided Design

Purpose This paper aims to achieve rapid design and manufacturing of personalized total knee femoral component. Design/methodology/approach On the basis of a patient’s bone model, a matching personalized knee femoral component was rapidly designed with the help of computer-aided design method, then manufactured directly and rapidly by selective laser melting (SLM). Considered SLM as manufacturing technology, CoCrMo-alloyed powder that meets ASTM F75 standard is made of femoral component under optimal processing parameters. The feasibility of SLM forming through conducting experimental test of mechanical properties, surface roughness, biological corrosion resistance was analyzed. Findings The result showed that the tensile strength, yield strength, hardness and biological corrosion resistance of CoCrMo-alloyed personalized femoral component fulfill knee joint prosthesis standard through post-processing. Originality/value Traditional standardized prosthesis implantation manufacturing approach was changed by computer-aided design and personalized SLM direct manufacturing, and provided a new way for personalized implanted prosthesis to response manufacturing rapidly.

Isogeometric independent coefficients method for fast reanalysis of structural modifications

2019 ◽  
Vol 37 (4) ◽  
pp. 1341-1368 ◽  
Author(s):  
Chensen Ding
Keyword(s):  
Real Time ◽  
Computer Aided Design ◽  
Numerical Solutions ◽  
Control Point ◽  
Structural Geometry ◽  
Content Type ◽  
Computer Aided ◽  
Practical Engineering ◽  
Cad Models ◽  
Local Modification

Purpose This paper aims to provide designers/engineers, in engineering structural design and analysis, approaches to freely and accurately modify structures (geometric and/or material), and then quickly provide real-time capability to obtain the numerical solutions of the modified structures (designs). Design/methodology/approach The authors propose an isogeometric independent coefficients (IGA-IC) method for a fast reanalysis of structures with geometric and material modifications. Firstly, the authors seamlessly integrate computer-aided design (CAD) and computer-aided engineering (CAE) by capitalizing upon isogeometric analysis (IGA). Hence, the authors can easily modify the structural geometry only by changing the control point positions without tedious transformations between CAE and CAD models; and modify material characters simply based on knots vectors. Besides, more accurate solutions can be obtained because of the high order degree of the spline functions that are used as interpolation functions. Secondly, the authors advance the proposed independent coefficients method within IGA for fast numerical simulation of the modified designs, thereby significantly reducing the enormous time spent in repeatedly numerical evaluations. Findings This proposed scheme is efficient and accurate for modifying the structural geometry by simply changing the control point positions, and material characters by knots vectors. The enormous time spent in repeated full numerical simulations for reanalysis is significantly reduced. Hence, enabling quickly modifying structural geometry and material, and analyzing the modified model for practicality in design stages. Originality/value The authors herein advance and propose the IGA-IC scheme. Where, it provides designers to fasten and simple designs and modify structures (both geometric and material). It then can quickly in real-time obtain numerical solutions of the modified structures. It is a powerful tool in practical engineering design and analysis process for local modification. While this method is an approximation method designed for local modifications, it generally cannot provide an exact numerical solution and its effectiveness for large modification deserves further study.

scholarly journals A CAD and AM process for maxillofacial prostheses bar-clip retention

2016 ◽  
Vol 22 (1) ◽  
pp. 170-177 ◽  
Author(s):  
Steffan Daniel ◽  
Dominic Eggbeer
Keyword(s):  
Computer Aided Design ◽  
Laser Scanning ◽  
Retention Mechanism ◽  
Additive Manufacture ◽  
Major Step ◽  
Content Type ◽  
Retention Mechanisms ◽  
Computer Aided ◽  
Patient Consultation ◽  
Consultation Time

Purpose – This paper aims to present novel techniques for designing maxillofacial prostheses using computer-aided design (CAD) and additive manufacture (AM), focusing on the integration of osseointegrated retention components. A fully computer-aided approach is considered as a major step towards reducing patient consultation time and an efficient workflow. Design/methodology/approach – The workflow was illustrated through a phantom model. 3D laser scanning was used to capture the phantom anatomy and pre-fabricated geometric features, which enabled the implant positions to be precisely reverse engineered in the data. A novel CAD workflow was used to design the retention mechanisms and a mould. The individual components were fabricated using AM. A definitive silicone prosthesis that incorporated a bar/clip retention mechanism was then fabricated. Findings – The research demonstrated that retention components can be integrated into prostheses using appropriate CAD and AM technologies. Originality/value – This study demonstrates the feasibility of a computer-aided workflow for designing facial prostheses that incorporate osseointegrated retention mechanisms. Novel techniques were developed to: digitise abutment details using custom scanning locators; design retention components; manufacture retention components using AM; integrate retention components into a CAD and AM prosthesis mould. This overcomes limitations identified in previously published cases and demonstrated significant potential to reduce patient consultation time and create a clinically viable process.

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