A Sensitivity Approach for Eliminating Clashes From Computer Aided Design Model Assemblies

Clashes occur when components in an assembly unintentionally violate others. If clashes are not identified and designed out before manufacture, product function will be reduced or substantial cost will be incurred in rework. This paper introduces a novel approach for eliminating clashes by identifying which parameters defining the part features in a computer aided design (CAD) assembly need to change and by how much. Sensitivities are calculated for each parameter defining the part and the assembly as the change in clash volume due to a change in each parameter value. These sensitivities give an indication of important parameters and are used to predict the optimum combination of changes in each parameter to eliminate the clash. Consideration is given to the fact that it is sometimes preferable to modify some components in an assembly rather than others and that some components in an assembly cannot be modified as the designer does not have control over their shape. Successful elimination of clashes has been demonstrated in a number of example assemblies.

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A trans-femoral brim adapter for CAD CAM measurements

Prosthetics and Orthotics International ◽

10.3109/03093649409164669 ◽

1994 ◽

Vol 18 (1) ◽

pp. 40-42 ◽

Cited By ~ 1

Author(s):

D. Nielen ◽

E. D. Lemaire ◽

L. Goudreau

Keyword(s):

Cost Saving ◽

Computer Aided Design ◽

Substantial Cost ◽

Substantial Cost Saving ◽

Computer Aided ◽

Cad Cam ◽

Aided Design

A computer aided design/computer aided manufacture (CAD CAM) brim measurement adapter was designed for use with a Berkeley casting stand. This measurement adapter accommodates all IPOS/CANFTT-PLUS transfemoral brim sizes and shapes, allows brim positioning, provides adequate stability, and provides a substantial cost saving by using existing, functional hardware as a base.

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3D Multi-Material Printing of an Anthropomorphic, Personalized Replacement Hand for Use in Neuroprosthetics Using 3D Scanning and Computer-Aided Design: First Proof-of-Technical-Concept Study

Prosthesis ◽

10.3390/prosthesis2040034 ◽

2020 ◽

Vol 2 (4) ◽

pp. 362-370

Author(s):

Jana Baron ◽

Simon Hazubski ◽

Andreas Otte

Keyword(s):

Computer Aided Design ◽

Concept Study ◽

Hand Model ◽

Flexible Material ◽

Novel Approach ◽

Computer Aided ◽

Flexible Part ◽

3D Printed ◽

Material Printing ◽

Aided Design

Background: This paper presents a novel approach for a hand prosthesis consisting of a flexible, anthropomorphic, 3D-printed replacement hand combined with a commercially available motorized orthosis that allows gripping. Methods: A 3D light scanner was used to produce a personalized replacement hand. The wrist of the replacement hand was printed of rigid material; the rest of the hand was printed of flexible material. A standard arm liner was used to enable the user’s arm stump to be connected to the replacement hand. With computer-aided design, two different concepts were developed for the scanned hand model: In the first concept, the replacement hand was attached to the arm liner with a screw. The second concept involved attaching with a commercially available fastening system; furthermore, a skeleton was designed that was located within the flexible part of the replacement hand. Results: 3D-multi-material printing of the two different hands was unproblematic and inexpensive. The printed hands had approximately the weight of the real hand. When testing the replacement hands with the orthosis it was possible to prove a convincing everyday functionality. For example, it was possible to grip and lift a 1-L water bottle. In addition, a pen could be held, making writing possible. Conclusions: This first proof-of-concept study encourages further testing with users.

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Solving Driving Forces of 2(3-SPR) Serial-Parallel Manipulator by CAD Variation Geometry Approach

Journal of Mechanical Design ◽

10.1115/1.2338577 ◽

2006 ◽

Vol 128 (6) ◽

pp. 1349-1351 ◽

Cited By ~ 25

Author(s):

Yi Lu ◽

Bo Hu

Keyword(s):

Computer Aided Design ◽

Parallel Manipulator ◽

Driving Forces ◽

Virtual Work ◽

Central Force ◽

Virtual Displacement ◽

Novel Approach ◽

Computer Aided ◽

Design Variation ◽

Aided Design

A novel 2(3-SPR) serial-parallel manipulator is proposed. A novel approach for solving driving forces of the 2(3-SPR) parallel manipulator is proposed by using the virtual work theory and the computer aided design variation geometry. The solving procedure of this method is divided into following steps: First, constitute an initial simulation mechanism by using link dimension chains and driving dimensions of driving limbs; and then constitute a workloads simulation mechanism by using central force and central torque on initial simulation mechanism; finally constitute the force/torque simulation mechanism by giving a virtual displacement to one of the driving limbs, so that the virtual displacement about force and torque can be drawn, the driven force of this driven limb can be calculated by using the virtual work theory. In the same way, the others driven forces can be gotten.

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Innovative approach to computer-aided design of horizontal axis wind turbine blades

Journal of Computational Design and Engineering ◽

10.1016/j.jcde.2016.11.001 ◽

2016 ◽

Vol 4 (2) ◽

pp. 98-105 ◽

Cited By ~ 6

Author(s):

Seyed Farhad Hosseini ◽

Behnam Moetakef-Imani

Keyword(s):

Wind Turbine ◽

Computer Aided Design ◽

Turbine Blades ◽

Hausdorff Metric ◽

Horizontal Axis ◽

Wind Turbine Blades ◽

Horizontal Axis Wind Turbine ◽

Novel Approach ◽

Computer Aided ◽

Aided Design

Abstract The design of horizontal axis wind turbine (HAWT) blades involves several geometric complexities. As a result, the modeling of these blades by commercial computer-aided design (CAD) software is not easily accomplished. In the present paper, the HAWT blade is divided into structural and aerodynamic surfaces with a G1 continuity imposed on their connecting region. The widely used method of skinning is employed throughout the current work for surface approximation. In addition, to ensure the compatibility of section curves, a novel approach is developed based on the redistribution of input airfoil points. In order to evaluate deviation errors, the Hausdorff metric is used. The fairness of surfaces is quantitatively assessed using the standard strain energy method. The above-mentioned algorithms are successfully integrated into a MATLAB program so as to enhance further optimization applications. The final surfaces created by the procedure developed during the present study can be exported using the IGES standard file format and directly interpreted by commercial CAD and FE software. Highlights A new skinning approach is presented based on redistribution of input data points. The developed skinning method is successfully applied to the design of horizontal axis wind turbine blades. It has been shown that the blade surface constructed using the developed method is fair and visually pleasing. Special attention has been paid to construct a smooth surface in the transition area between the root and the section with maximum chord.

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