1,721,104 research outputs found
A Framework for 3D Pattern Analysis and Reconstruction of Persian Architectural Elements
Full text linkPersian architecture is characterised by shapes and patterns, which can be analysed through mathematical models. Beside 2D patterns, many of the traditional geometric ornaments are realised on 3D surfaces such as domes or vaults. Literature mainly addresses the 3D problem by means of a 2D scheme, which is an important and synthetic representation but is not exhaustive and lacks of clarity. This paper proposes a framework based on the integration of 2D drawings, as in the traditional approach, and a photogrammetric 3D model based on a sample of standard resolution images (tourist pictures). The framework is tested on a muqarnas, a characteristic Persian ornament, in order to study and analyse its modular design and hierarchy of elements. As a case study, the entrance iwan of the Shah Mosque in Isfahan, Iran, is considered. The result is a link between the 3D patterns and the geometry of architectural elements, which completes and overcomes their schematic 2D representation
Multicriteria decision making methods in engineering design: an application on medical devices
Full text linkThe design of medical devices is challenging, due to strict geometry specifications and criteria belonging to several disciplines. Hence, design methods should be fol-lowed in a multicriteria decision making scenario, in order to satisfy constraints and select most suitable alternatives. The aim of this paper is to provide a design methodology which seems to lack in the literature of design of biomedical devic-es. This work attempts to highlight the peculiarities in the design of biomedical de-vices and the relative solution generation for a novel device. In particular, the case study proposed in this paper concerns with the design of Bone-Biopsy (BB) needle devices. Bone biopsy is a diagnostic procedure that involves taking a sam-ple of bone tissue to be analyzed in the laboratory. Following the design process of Pahl and Beitz, a functional analysis is carried out, to point out the interfaces between parts of existing bone biopsy needles. The core part of the product is the needle cannula holder, connecting the handle with the needle. Starting from a functional analysis of the components, a morphology matrix is used to generate alternatives. The Pugh’s Controlled Convergence method is used to score and rank alternatives in relation to the decision makers’ opinions. In this work, the de-sign peculiarities related to the BB needles which have been pointed out could be extended for guiding the design of other biomedical devices
Digital engineering methods for enhanced flexibility of robofacturing (robotic manufacturing) applications
No full textA digital engineering method was developed to enhance robotic cell flexibility in industrial manufacturing applications. Computer Aided 3D parametric modeling, behavioural simulation, offline programming were integrated into the design process to define and generate robotic cell virtual prototypes. Resulting information and data were primarily used during design and engineering stages for optimizing the cell layout and for assuring best performances in cycle time reduction and manufacturing path accuracy. Then digital models were simplified and fit within customizable virtual environment, developed for allowing final users to quick re-configure the robotic cell and re-program robots without any specific competence on robotics. The robotic deburring and finishing manufacturing of crankshaft for V8 and V12 high-performance engines was investigated through the method developed. A cell prototype was finally realized by R&D engineers from SIR S.p.A. (www.sir-mo.it) and researchers from the Department of Mechanical and Civil Engineering, sharing competences, experiences and technical resources within the Integrated Design and Simulation of Robotic Systems Lab, a novel Industry/University hybrid structure. Such digital engineering method applied to a robotic manufacturing problem leaded to the theorization of a “Design for Robotic Manufacturing (“Robofacturing”)” approach, finally called. Robotic cell flexibility was enhanced providing final users a digital engineering service for manufacturing cell re-configuration and robot re-programming
ANOVA OF 3D VARIATIONAL MODELS FOR COMPUTER AIDED TOLERANCING WITH RESPECT TO THE MODELING FACTORS
No full textSheet metal assemblies are subjected to errors as deformations due to material, thickness, geometries and process variations. Advanced simulations enable the optimization of product features, GD&T scheme and assembly process. The 3D error propagation due to the different contributors can be studied with Variational Models of the product and assembly system. However, the practical application of these methods is limited by the high number of factors in the models, which makes the operator experience fundamental to achieve their trustworthiness. Guidelines for modeling the sheet metal assemblies are needed. The present work aims at analysing the variations in the model with a Design of Computer Experiments (DoCE) plan. A case study on an automotive fender is discussed. The results demonstrate that the modeling strategy of clamping operation have the major effects, while the modeling of locators scheme, spot joints and FEM meshing are less important
REDESIGN FOR ENVIRONMENT OF WOODEN PACKAGING FOR BULK RECYCLING AND RECOVERY. ARPN Journal of Engineering and Applied Sciences VOL. 11, NO. 1, JANUARY 2016.
No full textSociety increasingly demands for effective waste management policies to make industries more environmentally
sustainable. Organizations are even issuing directives to drive choices about these policies. In particular, modern industries
produce a lot of packaging, which soon become waste, even before product usage. Research can face the problem with
improvements in recycling and recovery processes. However, even if recycling and recovery would enable waste to have
still a value, most costs and benefits are determined at the design stage. Therefore, Design for Environment criteria must be
adopted in the design tasks, from the early conceptual design when the main design solutions are defined. The design
criteria to assess possible design choices must consider all the environmental impacts of packaging over its lifecycle. The
present work focuses on Redesign for Environment of packaging solutions. Following a systematic design process, we use
different criteria to evaluate the effects of design solutions on packaging, since waste can be seen just as one of the main
phases of packaging life. To this purpose, we adopt the stages of the waste hierarchy set by the EU Waste Framework
Directive 2008/98/EC as design evaluation criteria. The waste hierarchy sets a priority order for five life cycle stages that a
packaging can go through. The stages of the hierarchy can be differently weighted according to the costs and benefits they
involve. The proposed Design for Environment method based on the waste hierarchy criteria is finally applied in the
redesign of an industrial case study. The packaging solution as foldable wooden crates were chosen for their capability to
already comply with the first stages of the hierarchy, that is reducing waste with high customization to customer
requirements and crate reuse. Hence, the case study improved the next stages with easing the wood recycle and recovery
processe
A review on decision-making methods in engineering design for the automotive industry
No full textDecision-making methods have proven to be an effective support to
engineering design. However, it is proved that very often designers
prefer tested procedures and experience-based approaches. Many
reasons have been discussed in the literature, dealing with consolidated
design habits of people and companies, high cost in terms
of time consumption, and lack of tools and knowledge. The paper
systematically investigates, through an extended critical review, how
decision-making methods can be used by automotive designers to
solve the most common engineering problems involved along the
design process. In particular, the paper proposes an original classification
of the most widely used decision-making methods in engineering
design, a match between such techniques with the typical
design phases, and a mapping of their application into the automotive
field. This research can be considered as a further step to
transfer the state-of-the-art knowledge on decision- making methods
to the industrial context, establishing a common background for
practitioners and researchers
Integrated Product and Process Design for Robotic Additive Manufacturing
No full textRobotic Additive Manufacturing is an emerging trend thanks to effective advances compared to traditional machines based on Cartesian movements. Reduction of the volume of supports and the related “staircase effect” increased inaccuracy and surface roughness, large printing volumes, more flexibility on the printing strategy, and use of multiple materials are just some of the potential benefits returned by robotic additive manufacturing. Nevertheless, the selection of suitable strategies, planning of the printing trajectories and definition of the related code to drive the robot movements are still managed by different digital tools that make it challenging to identify the optimal process. This work describes a Design for Robotic Additive Manufacturing approach to support the development of the printing process driven by complex machines such as robotic arms. Based on an available computer-aided design platform, the digital replica of the robotic system is recreated, and additive process alternatives are applied to simulate the fabrication of an automotive part. A first assessment of the design integration by the approach suggested is evaluated by the simulation of fuse material deposition for a simplified version of the selected use case
Guest editorial note: Special issue on human-robot collaboration in industrial applications
No full textFocusing on these challenges, this Special Issue in Mechatronics aims at providing an up-to-date overview of recent advanced solutions that can significantly promote HRC in industrial scenarios, with an emphasis on the mechatronic aspects related to the design of integrated systems, knowledge sharing between human and robots, modelling and simulation of interaction and safety countermeasures. The central theme of the Special Issue is the development of systems, methodologies, and new concepts for crossing the gap between laboratories and reality that will help foster the adoption of human-robot collaborative solutions to real-world industrial applications
Integrated Design of a Robotic Cell for Lasts Roughing.
No full textA computer simulation based methodology was elaborated for the integrated design and development of a footwear lasts roughing robotic cell, developed by DIMeC (University of Modena and Reggio Emilia, Italy) researchers and the design engineers of SIR S.P.A., an italian robot system integrator market-leader. The integration of different design and simulation software tools leads to a time and cost-saving procedure to be used in the design of high-performance robotic manufacturing cells, with increased machining quality, flexibility, low set-up time and ease of re-configurability. A Concurrent Engineering approach was followed throughout all the stages of the robotic cell development, while behavioral simulation and off-line programming performed on the definitive model allowed to close the Computer Integrated design process loop
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