Automatic Determination of Feature Interactions in Design-for-Manufacturing Analysis

1995 ◽  
Vol 117 (1) ◽  
pp. 2-9 ◽  
Author(s):  
R. Gadh ◽  
F. B. Prinz

The current paper discusses a fundamentally new approach to defining and finding interactions in computer-aided design (CAD) forms or features. Feature classes are defined using a high-level abstract entity called a loop. Loops define features in a general manner and aid in the definition of feature boundaries as well. Interactions between features exist due to interactions between their boundaries. Several types of interactions are defined and automatically determined from the boundary representation solid model of the part subsequent to performing feature extraction.

Author(s):  
Thomas R. Langerak ◽  
Joris S. M. Vergeest

Modeling with free form features has become the standard in Computer-Aided Design (CAD). With the increasing complexity of free form CAD models, features offer a high-level approach to modeling shapes. However, in most commercial modeling packages, only a static set of free form features is available. Researchers have tried to solve this problem by coming up with methods for user-driven free form feature definition, but failed to connect their methods to a means to instantiate these user-driven free form features on a target surface. Reversely, researchers have proposed tools for modeling with free form features, but these methods are time-intensive in that they are as of yet unsuitable for pre-defined features. This paper presents a new method for user-driven feature definition, as well as a method to instantiate these user-defined features on a target surface. We propose the concept of a dual environment, in which the definition of a feature is maintained simultaneously with its instance on a target surface, allowing the user to modify the definition of an already instantiated feature. This dual environment enables dynamic feature modeling, in which the user is able to change the definition of instantiated features on-the-fly. Furthermore, the proposed instantiation method is independent from the type of shape representation of the target surface and thereby increases the applicability of the method. The paper includes an extensive application example and discusses the results and shortcomings of the proposed methods.


Author(s):  
Thomas R. Langerak ◽  
Joris S. M. Vergeest

Modeling with freeform features has become the standard in computer-aided design. Features offer a high-level approach to modeling shapes. However, in most commercial modeling packages, only a static set of freeform features is available. A new method for user-driven feature definition is presented, as well as a method to instantiate these user-defined features on a target surface. We propose the concept of a dual environment, in which the definition of a feature is maintained parallel to its instance on a target surface. This dual environment enables dynamic feature modeling, in which the user is able to change the definition of instantiated features on-the-fly.


Author(s):  
Rajit Gadh ◽  
Fritz B. Prinz

Abstract The current paper discusses a fundamentally new approach to defining and finding interactions in computer-aided design (CAD) forms or features. The paper provides a classification of the various interactions found among CAD forms. The paper also illustrates a robust approach to defining and recognizing stand-alone as well as interacting forms. The problem of generic form definition is resolved using a set of high-level abstract entities called loops and links. The computational difficulty in finding the forms is resolved using a mathematically defined geometric filter called the Differential Depth Filter.


Author(s):  
Romain Desplats ◽  
Timothee Dargnies ◽  
Jean-Christophe Courrege ◽  
Philippe Perdu ◽  
Jean-Louis Noullet

Abstract Focused Ion Beam (FIB) tools are widely used for Integrated Circuit (IC) debug and repair. With the increasing density of recent semiconductor devices, FIB operations are increasingly challenged, requiring access through 4 or more metal layers to reach a metal line of interest. In some cases, accessibility from the front side, through these metal layers, is so limited that backside FIB operations appear to be the most appropriate approach. The questions to be resolved before starting frontside or backside FIB operations on a device are: 1. Is it do-able, are the metal lines accessible? 2. What is the optimal positioning (e.g. accessing a metal 2 line is much faster and easier than digging down to a metal 6 line)? (for the backside) 3. What risk, time and cost are involved in FIB operations? In this paper, we will present a new approach, which allows the FIB user or designer to calculate the optimal FIB operation for debug and IC repair. It automatically selects the fastest and easiest milling and deposition FIB operations.


2018 ◽  
Vol 875 ◽  
pp. 71-76
Author(s):  
Victor Kryaskov ◽  
Andrey Vashurin ◽  
Anton Tumasov ◽  
Alexey Vasiliev

This paper is dedicated to the issues of designing of outriggers for avoidance of vehicle tilting during its stability tests. An analysis of existing types of outriggers was done by authors as well as legislative requirements on them. The reliable and well-timed operation of outriggers largely depends on the height of their positioning on a vehicle. In order to determine this important parameter a special methodic of determining the tipping angle of the vehicle with the use of computer-aided design (CAD) was composed by authors. The article also contains some main principles of strength analysis of the structure a very important part of which became the necessity of determination of coefficient of friction between the outrigger sliders and the supporting surface. This coefficient has a direct impact on the value of transverse forces appearing at the ends of outrigger beams.


Author(s):  
Andreas Apostolatos ◽  
Altuğ Emiroğlu ◽  
Shahrokh Shayegan ◽  
Fabien Péan ◽  
Kai-Uwe Bletzinger ◽  
...  

AbstractIn this study the isogeometric B-Rep mortar-based mapping method for geometry models stemming directly from Computer-Aided Design (CAD) is systematically augmented and applied to partitioned Fluid-Structure Interaction (FSI) simulations. Thus, the newly proposed methodology is applied to geometries described by their Boundary Representation (B-Rep) in terms of trimmed multipatch Non-Uniform Rational B-Spline (NURBS) discretizations as standard in modern CAD. The proposed isogeometric B-Rep mortar-based mapping method is herein extended for the transformation of fields between a B-Rep model and a low order discrete surface representation of the geometry which typically results when the Finite Volume Method (FVM) or the Finite Element Method (FEM) are employed. This enables the transformation of such fields as tractions and displacements along the FSI interface when Isogeometric B-Rep Analysis (IBRA) is used for the structural discretization and the FVM is used for the fluid discretization. The latter allows for diverse discretization schemes between the structural and the fluid Boundary Value Problem (BVP), taking into consideration the special properties of each BVP separately while the constraints along the FSI interface are satisfied in an iterative manner within partitioned FSI. The proposed methodology can be exploited in FSI problems with an IBRA structural discretization or to FSI problems with a standard FEM structural discretization in the frame of the Exact Coupling Layer (ECL) where the interface fields are smoothed using the underlying B-Rep parametrization, thus taking advantage of the smoothness that the NURBS basis functions offer. All new developments are systematically investigated and demonstrated by FSI problems with lightweight structures whereby the underlying geometric parametrizations are directly taken from real-world CAD models, thus extending IBRA into coupled problems of the FSI type.


2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Andrew Johnson ◽  
Xianwen Kong ◽  
James Ritchie

The determination of workspace is an essential step in the development of parallel manipulators. By extending the virtual-chain (VC) approach to the type synthesis of parallel manipulators, this technical brief proposes a VC approach to the workspace analysis of parallel manipulators. This method is first outlined before being illustrated by the production of a three-dimensional (3D) computer-aided-design (CAD) model of a 3-RPS parallel manipulator and evaluating it for the workspace of the manipulator. Here, R, P and S denote revolute, prismatic and spherical joints respectively. The VC represents the motion capability of moving platform of a manipulator and is shown to be very useful in the production of a graphical representation of the workspace. Using this approach, the link interferences and certain transmission indices can be easily taken into consideration in determining the workspace of a parallel manipulator.


Mechanik ◽  
2018 ◽  
Vol 91 (7) ◽  
pp. 529-531
Author(s):  
Jolanta Krystek ◽  
Sara Alszer ◽  
Szymon Bysko

Presented is the concept of paint shop operation for the automotive industry – Paint Shop 4.0, based on the ideas of Industry 4.0 and Digital Factory. A new approach to the issue of car body sequencing, taking into account the actual structure of the paint shop department with buffers, has been presented. In the created application, proprietary car body sequencing algorithms were implemented.


2006 ◽  
Vol 12 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Vladimir Popov ◽  
Saulius Mikalauskas ◽  
Darius Migilinskas ◽  
Povilas Vainiūnas

With the growth of information technologies in the field of construction industry, the concept of CAD (Computer Aided Design), which denotes just design operations using a computer acquires a new meaning and changes the contents lightening design process based on product modelling and further numerical simulation construction process and facility managing. New definitions as Building Information Modelling (BIM) and Product Lifecycle Management (PLM) are more and more usable as the definition of a new way approaching the design and documentation managing of building projects. The presented computer aided design technology based on the concept of graphical ‐ information modeling of a building, is combined with resource demand calculations, comparison of alternatives and determination of duration of all the stages of investment project life. The software based on this combined 4D PLM model is to be created as a means to manage effectively the investment project, starting from planning, designing, economical calculations, construction and afterwards to manage the finished building and to utilize it.


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