scholarly journals Determination of contact pattern for double enveloping worm gear

2020 ◽  
Vol 44 (4) ◽  
pp. 145-154
Author(s):  
Piotr Polowniak ◽  
Mariusz Sobolak ◽  
Adam Marciniec
Keyword(s):  
Contact Area ◽  
Computer Aided Design ◽  
Worm Gear ◽  
Complete Analysis ◽  
Contact Pattern ◽  
Tooth Contact Analysis ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

AbstractThe paper presents the method of determining geometric contact pattern by using the direct computer-aided design (CAD) method for ideal globoid worm gear in which mounting deviations are considered. The tooth contact analysis was performed for all cycle of worm rotation. Based on the results of temporary contact pattern, graphical characteristics of the contact area size depending on worm position were made. A complete analysis of the correctness of gear meshing can be obtained based on presented method. If the worm or worm wheel is incorrectly designed in terms of the geometry, the meshing simulation of CAD models can indicate the collision. Geometric contact pattern analyses were made at two pressure angles of ideal gear. The analysis of the influence of mounting deviations was done against one selected pressure angle and one gear position.

Designing of Outriggers for the Needs of the Vehicles Stability Testing

2018 ◽  
Vol 875 ◽  
pp. 71-76
Author(s):  
Victor Kryaskov ◽  
Andrey Vashurin ◽  
Anton Tumasov ◽  
Alexey Vasiliev
Keyword(s):  
Coefficient Of Friction ◽  
Computer Aided Design ◽  
Strength Analysis ◽  
Direct Impact ◽  
Stability Testing ◽  
Supporting Surface ◽  
Stability Tests ◽  
Computer Aided ◽  
Aided Design

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.

scholarly journals Automatized Evaluation of Students’ CAD Models

2021 ◽  
Vol 11 (4) ◽  
pp. 145
Author(s):  
Nenad Bojcetic ◽  
Filip Valjak ◽  
Dragan Zezelj ◽  
Tomislav Martinec
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Computer Application ◽  
Test Cases ◽  
Cad Model ◽  
Computer Solution ◽  
3D Cad ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

The article describes an attempt to address the automatized evaluation of student three-dimensional (3D) computer-aided design (CAD) models. The driving idea was conceptualized under the restraints of the COVID pandemic, driven by the problem of evaluating a large number of student 3D CAD models. The described computer solution can be implemented using any CAD computer application that supports customization. Test cases showed that the proposed solution was valid and could be used to evaluate many students’ 3D CAD models. The computer solution can also be used to help students to better understand how to create a 3D CAD model, thereby complying with the requirements of particular teachers.

Determination of the Workspace of a Three-Degrees-of-Freedom Parallel Manipulator Using a Three-Dimensional Computer-Aided-Design Software Package and the Concept of Virtual Chains1

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Andrew Johnson ◽  
Xianwen Kong ◽  
James Ritchie
Keyword(s):  
Computer Aided Design ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Graphical Representation ◽  
Three Dimensional ◽  
Parallel Manipulators ◽  
Workspace Analysis ◽  
Computer Aided ◽  
Aided Design

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.

scholarly journals COMPLEX USAGE OF 4D INFORMATION MODELLING CONCEPT FOR BUILDING DESIGN, ESTIMATION, SHEDULING AND DETERMINATION OF EFFECTIVE VARIANT

2006 ◽  
Vol 12 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Vladimir Popov ◽  
Saulius Mikalauskas ◽  
Darius Migilinskas ◽  
Povilas Vainiūnas
Keyword(s):  
Computer Aided Design ◽  
Information Technologies ◽  
Investment Project ◽  
Building Design ◽  
Product Lifecycle Management ◽  
Information Modeling ◽  
Information Modelling ◽  
Computer Aided ◽  
Aided Design

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.

A New Family of Bricard-Derived Deployable Mechanisms

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Hailin Huang ◽  
Bing Li ◽  
Jianyang Zhu ◽  
Xiaozhi Qi
Keyword(s):  
Large Volume ◽  
Computer Aided Design ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
New Family ◽  
Revolute Joints ◽  
Computer Aided ◽  
Cad Models ◽  
Aided Design

This paper proposes a new family of single degree of freedom (DOF) deployable mechanisms derived from the threefold-symmetric deployable Bricard mechanism. The mobility and geometry of original threefold-symmetric deployable Bricard mechanism is first described, from the mobility characterstic of this mechanism, we show that three alternate revolute joints can be replaced by a class of single DOF deployable mechanisms without changing the single mobility characteristic of the resultant mechanisms, therefore leading to a new family of Bricard-derived deployable mechanisms. The computer-aided design (CAD) models are used to demonstrate these derived novel mechanisms. All these mechanisms can be used as the basic modules for constructing large volume deployable mechanisms.

Orthogonal Distance Fields Representation for Machine-Learning Based Manufacturability Analysis

2020 ◽  
Author(s):  
Aditya Balu ◽  
Sambit Ghadai ◽  
Soumik Sarkar ◽  
Adarsh Krishnamurthy
Keyword(s):  
Machine Learning ◽  
Computer Aided Design ◽  
Boundary Representation ◽  
Engineering Product ◽  
Distance Fields ◽  
Computer Aided ◽  
Cad Models ◽  
Product Design Process ◽  
3D Cnn ◽  
Aided Design

Abstract Computer-aided Design for Manufacturing (DFM) systems play an essential role in reducing the time taken for product development by providing manufacturability feedback to the designer before the manufacturing phase. Traditionally, DFM rules are hand-crafted and used to accelerate the engineering product design process by integrating manufacturability analysis during design. Recently, the feasibility of using a machine learning-based DFM tool in intelligently applying the DFM rules have been studied. These tools use a voxelized representation of the design and then use a 3D-Convolutional Neural Network (3D-CNN), to provide manufacturability feedback. Although these frameworks work effectively, there are some limitations to the voxelized representation of the design. In this paper, we introduce a new representation of the computer-aided design (CAD) model using orthogonal distance fields (ODF). We provide a GPU-accelerated algorithm to convert standard boundary representation (B-rep) CAD models into ODF representation. Using the ODF representation, we build a machine learning framework, similar to earlier approaches, to create a machine learning-based DFM system to provide manufacturability feedback. As proof of concept, we apply this framework to assess the manufacturability of drilled holes. The framework has an accuracy of more than 84% correctly classifying the manufacturable and non-manufacturable models using the new representation.

Paired Computer-Aided Design: The Effect of Collaboration Mode on Differences in Model Quality

2020 ◽  
Author(s):  
Hamza Arshad ◽  
Vrushank Phadnis ◽  
Alison Olechowski
Keyword(s):  
Computer Aided Design ◽  
Shared Control ◽  
Control Mode ◽  
Pair Programming ◽  
Design Teams ◽  
Model Quality ◽  
Computer Aided ◽  
Parallel Cad ◽  
Cad Models ◽  
Aided Design

Abstract We present the results of an experiment investigating two different modes of collaboration on a series of computer-aided design (CAD) tasks. Inspired by the pair programming literature, we anticipate that partners working in a fully synchronous collaborative CAD environment will achieve different levels of quality in CAD models depending on their mode of collaboration — one in which the pair is free to work in parallel, and another where the pair must coordinate to share one control. We found that a shared CAD control led to significantly better overall CAD quality than parallel CAD control. In addition, the shared control mode led to more complete and consistent CAD models, as well as the tendency for participants to follow instructions to correctly replicate features for the design task. As is predicted in the literature, a trade-off relationship (albeit weak) between quality and speed via the parallel collaboration was found. In contrast, the shared control mode shows no clear relationship between speed and quality. Collaborative CAD is increasingly seen as an appealing tool for modern product design teams. This study suggests that the benefits of this tool are not solely the effect of the tool itself, but result from the collaboration style of the designers using the tool.

A Method of Determining the Direction of Two Dimensional Curves

2014 ◽  
Vol 980 ◽  
pp. 159-164
Author(s):  
F. Wang ◽  
R.K.F. Abdelmaguid ◽  
H.M.A. Hussein
Keyword(s):  
Computer Aided Design ◽  
Tangent Vector ◽  
Two Dimensional ◽  
Linear Algorithm ◽  
Complete Cycle ◽  
Angular Change ◽  
Computer Aided ◽  
Aided Design ◽  
Relationship Of

Two-dimensional curves are represented by a list of vertices and other parameters that control the shape or curvature of the segments. In computer programming to deal with closed two-dimensional curves, it is often required to know the direction of the curve, which is reflected by the sequence of the vertex data. It can be anticlockwise or clockwise. This paper presents a robust, linear algorithm to determine the direction of a closed two-dimensional curve, by computing the total angular change of a tangent vector travelling along the curve for a complete cycle. A new, robust linear algorithm is proposed for the determination of the positional relationship of a point to a two-dimensional curve. For curves that consist of line and arc segments, which are most commonly used in engineering applications in computer aided design, the paper presents algorithms and procedures for solving the above problems.

Computation of Midsurface by Feature-Based Simplification–Abstraction–Decomposition

2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Yogesh H. Kulkarni ◽  
Anil Sahasrabudhe ◽  
Mukund Kale
Keyword(s):  
Computer Aided Design ◽  
Real Life ◽  
Boundary Representation ◽  
Manual Task ◽  
Computer Aided ◽  
Cad Models ◽  
Feature Based ◽  
Feature Information ◽  
Plastic Parts ◽  
Aided Design

Computer-aided design (CAD) models of thin-walled solids such as sheet metal or plastic parts are often reduced dimensionally to their corresponding midsurfaces for quicker and fairly accurate results of computer-aided engineering (CAE) analysis. Computation of the midsurface is still a time-consuming and mostly, a manual task due to lack of robust and automated techniques. Most of the existing techniques work on the final shape (typically in the form of boundary representation, B-rep). Complex B-reps make it hard to detect subshapes for which the midsurface patches are computed and joined, forcing usage of hard-coded heuristic rules, developed on a case-by-case basis. Midsurface failures manifest in the form of gaps, overlaps, nonmimicking input model, etc., which can take hours or even days to correct. The research presented here proposes to address these problems by leveraging feature-information available in the modern CAD models, and by effectively using techniques like simplification, abstraction, and decomposition. In the proposed approach, first, the irrelevant features are identified and removed from the input FbCAD model to compute its simplified gross shape. Remaining features then undergo abstraction to transform into their corresponding generic Loft-equivalents, each having a profile and a guide curve. The model is then decomposed into cellular bodies and a graph is populated, with cellular bodies at the nodes and fully overlapping-surface-interfaces at the edges. The nodes are classified into midsurface-patch generating nodes (called “solid cells” or sCells) and interaction-resolving nodes (“interface cells” or iCells). In a sCell, a midsurface patch is generated either by offset or by sweeping the midcurve of the owner-Loft-feature's profile along with its guide curve. Midsurface patches are then connected in the iCells in a generic manner, thus resulting in a well-connected midsurface with minimum failures. Output midsurface is then validated topologically for correctness. At the end of this paper, real-life parts are used to demonstrate the efficacy of the proposed approach.

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