Search results for "Computer Aided Design"
showing 10 items of 40 documents
Augmented Reality Aided 3D Modelling
2014
The purpose of the article is to introduce possibilities of using Augmented Reality instructions in order to better understand technical drawings. The aim of these instructions based on 3D models is to create AR training applications and analyze their impact on the users. These instructions consist in a 3D model, superimposed over the technical drawing. The AR application also offers step by step instructions for 3D modelling in CAD software, which are very useful in creating the 3D model starting from a technical drawing. The AR application was tested by students from the Faculty of Engineering in Sibiu, obtaining great improvements in their 3D modelling times. The results of a survey that…
Parametric Hull Design with Rational Bézier Curves and Estimation of Performances
2021
In this paper, a tool able to support the sailing yacht designer during the early stage of the design process has been developed. Cubic Rational Bézier curves have been selected to describe the main curves defining the hull of a sailing yacht. The adopted approach is based upon the definition of a set of parameters, say the length of waterline, the beam of the waterline, canoe body draft and some dimensionless coefficients according to the traditional way of the yacht designer. Some geometrical constraints imposed on the curves (e.g., continuity, endpoint angles, curvature) have been conceived aimed to avoid unreasonable shapes. These curves can be imported into any commercial Computer Aide…
SOFTWARE FOR DRILLING TOOL DESIGN AND MANUFACTURING
2007
Abstract The paper presents a software that allows the design and manufacturing of cutting tools for boring. The methodology contains several steps that can be taken only by using the software modules. The main stages are the geometrical and dimensional design of the cutting tool, the design and generation of the abrasive profiled disks, the management of abrasive disks and disk package, the generation of the manufacturing technology, the verification of the cutting tool using virtual simulation, testing the manufacturing process using virtual simulation, generating the CNC files and finally the transmission of the CNC files in real time to the CNC machine tool so that the tools can be manu…
On-Line Control of Single Point Incremental Forming Operations through Punch Force Monitoring
2006
Abstract Among the innovative sheet metal forming processes, Single Point Incremental Forming (SPIF) represents the simplest and the cheapest one. Despite its relevant advantages, up to now no specific CAE tools for SPIF were developed and the tool trajectory is generally defined utilizing CAD/CAM software developed for machining applications. In the paper an innovative monitoring and control approach, aimed to define and in-process update the most relevant process parameters during an industrial SPIF operation, is proposed. The strategy utilizes as monitoring variable the punch force trend: a set of preliminary tests demonstrated, in fact, its suitability as “spy variable” of the process m…
GPCALMA, a mammographic CAD in a GRID connection
2003
Purpose of this work is the development of an automatic system which could be useful for radiologists in the investigation of breast cancer. A breast neoplasia is often marked by the presence of microcalcifications and massive lesions in the mammogram: hence the need for tools able to recognize such lesions at an early stage. GPCALMA (Grid Platform Computer Assisted Library for MAmmography), a collaboration among italian physicists and radiologists, has built a large distributed database of digitized mammographic images (at this moment about 5500 images corresponding to 1650 patients). This collaboration has developed a CAD (Computer Aided Detection) system which, installed in an integrated…
Multi-objective optimization of nitinol stent design.
2017
Nitinol stents continuously experience loadings due to pulsatile pressure, thus a given stent design should possess an adequate fatigue strength and, at the same time, it should guarantee a sufficient vessel scaffolding. The present study proposes an optimization framework aiming at increasing the fatigue life reducing the maximum strut strain along the structure through a local modification of the strut profile.The adopted computational framework relies on nonlinear structural finite element analysis combined with a Multi Objective Genetic Algorithm, based on Kriging response surfaces. In particular, such an approach is used to investigate the design optimization of planar stent cell.The r…
HEMT for low-noise microwaves: CAD-oriented performance evaluation
1995
This paper shows how a graphic processing of low-noise HEMT's small signal parameters, allows evaluating and comparing the actual performance obtainable in front-end applications. HEMT's tradeoff charts which solve tradeoffs among the basic low-noise amplifier performance are reported. Figures of merit for microwave low-noise HEMT which represent a fast way of evaluating HEMT in actual working conditions and of selecting the proper transistor, are defined. As an example, the tradeoff charts and the figures of merit of two HEMT's (Fujitsu FHR02FH, Sony 2SK677) and a pseudomorphic-HEMT (Celeritek CFB001-03) are reported and compared with the data sheets. © 1995, IEEE. All rights reserved.
Fast automated design of waveguide filters using aggressive space mapping with a new segmentation strategy and a hybrid optimization algorithm
2005
Waveguide filters are key elements present in many microwave and millimeter-wave communication systems. In recent times, ever-increasing efforts are being devoted to the development of automated computer-aided design (CAD) tools of such devices. In this paper, a novel CAD tool based on modal analysis methods, which improves the efficiency and robustness of the classical aggressive space-mapping technique, is presented for those purposes. The use of a new segmentation strategy and the hybridization of a specific combination of several well-known optimization algorithms is proposed. The CAD tool has been successfully validated with the practical design of several H-plane coupled cavity filter…
Efficient Analysis and Design Strategies for Evanescent Mode Ridge Waveguide Filters
2006
In this paper, a research on the compromises arisen in the design of traditional evanescent mode waveguide filters is carried out. As a result, clear design methodologies for optimizing length, losses, power handling and spurious-free out-of-band response are developed. In addition, an efficient and very accurate modal analysis tool for this kind of structures is presented. Several filters have been designed according to the different strategies proposed, and a prototype has been finally manufactured. Measurements and filter dimensions validate the proposed design procedures.
Third-order accurate monotone cubic Hermite interpolants
2019
Abstract Monotonicity-preserving interpolants are used in several applications as engineering or computer aided design. In last years some new techniques have been developed. In particular, in Arandiga (2013) some new methods to design monotone cubic Hermite interpolants for uniform and non-uniform grids are presented and analyzed. They consist on calculating the derivative values introducing the weighted harmonic mean and a non-linear variation. With these changes, the methods obtained are third-order accurate, except in extreme situations. In this paper, a new general mean is used and a third-order interpolant for all cases is gained. We perform several experiments comparing the known tec…