analysis of debonding in bio inspired interfaces obtained by additive manufacturing

Abstract The present work is focused on the analysis of fracture in adhesive bonded Double Cantilever Beam (DCB) specimens with 3D printed nylon substrates. The substrates were obtained using selective laser sintering of polyamide powder and embed sub-surface channels with circular and square cross-section. The proposed strategy allows to mimic the crack trapping effect already observed in a multitude of biological materials, that is originated by the spatial modulation of the driving force available for crack growth. Mechanical tests have shown that the channels induce load fluctuations in the global load-displacement response. A significant increase in the total dissipated energy was observed with respect to bulk samples, i.e. no channels. The observed fluctuations in the global response were associated to the sequential storage and sudden release of elastic energy. Indeed, the spatial modulation of the stiffness around the interfacial region ultimately affects the crack driving force

Surveying pasture communities in diachronic analyses by 3D models: the diachronic canopy variation model

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Performance-Driven Engineering Design Approaches Based on Generative Design and Topology Optimization Tools: A Comparative Study

The advent of Additive Manufacturing (AM) is uncovering the limits of the current CAD systems and, at the same time, is highlighting the potentials of the Topology Optimization (TO) and Generative Design (GD) tools that had not been fully exploited until now. Differently from the traditional design approach in which designers occupy a predominant role in each stage of the design process, the introduction of such tools in the product development process pushes toward simulation-driven design approaches which imply a significant change in the role of the designer. To this end, the paper presents a comparison of two different design methods for Additive Manufacturing based on the adoption of TO and GD tools. The comparison aims to offer a reflection on the evolution of the traditional approach when TO and GD tools are used, and to highlight the potential and limitations of these optimization tools when adopted in an integrated manner with the CAD systems. Furthermore, this comparative study can be a useful and practical source for designers to identify the most appropriate approach to adopt based on their needs and project resources. The comparative study is carried out through the design study of a prototype of a rocker arm and a brake pedal for the Formula Student race car. Their results, compared in terms of mechanical performances, show that both TO and especially GD tools can be efficiently adopted early in a design process oriented to AM to redesign components to make them lighter and stronger

Identifying Partners And Organizational Logical Structures For Collaborative Conceptual Design

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Innovative methodologies and tools for the interaction with Virtual Prototypes

Dottorato di Ricerca in Igegneria Meccanica XX Ciclo,a.a. 2006-2007Università della Calabri

Studio del comportamento dinamico dei veicoli da competizione mediante analisi parametrica in ambiente multibody

Dottorato di Ricerca in Ingegneria Meccanica, Ciclo XIX a.a. 2004-2006Università della Calabri

Strumenti e metodi di prototipazione virtuale nella progettazione dell'autoveicolo: dal reverse engineering all'integrazione FEM/Multibody

Dottorato di Ricerca in Ingegneria Meccanica, Ciclo XIX, a.a. 2004-2006Università della Calabri

Functional behaviour simulation of industrial products in virtual reality

VR (Virtual Reality) is a powerful tool for the simulation of virtual prototypes, because it allows engineers to enhance the analysis and validation of the digital product before manufacturing any physical mock-up. Unfortunately, VR software tools are not able to fully simulate the behaviour of a virtual product, because they are mainly conceived to reproduce the visual appearance of the product: the functional simulation is limited to basic behaviours related to the animation of the objects in the virtual world (e.g.: part movements). This paper describes an innovative approach to create functional behaviour simulations in VR using the same models and the same software employed by the engineers in the design phase. Our approach is based on the run-time connection between the VR software and the simulators used for product design and analysis. This means that there is no need to write code for describing the product behaviour, and any modification done on the behaviour models is immediately testable in VR. It is apparent that these advantages allow to reduce the time needed to implement the virtual prototyping, thus achieving a more efficient design process. © Organizing Committee of TMCE 2010 Symposium.status: publishe

A Comparative Analysis between Active and Passive Techniques for Underwater 3D Reconstruction of Close-Range Objects

In some application fields, such as underwater archaeology or marine biology, there is the need to collect three-dimensional, close-range data from objects that cannot be removed from their site. In particular, 3D imaging techniques are widely employed for close-range acquisitions in underwater environment. In this work we have compared in water two 3D imaging techniques based on active and passive approaches, respectively, and whole-field acquisition. The comparison is performed under poor visibility conditions, produced in the laboratory by suspending different quantities of clay in a water tank. For a fair comparison, a stereo configuration has been adopted for both the techniques, using the same setup, working distance, calibration, and objects. At the moment, the proposed setup is not suitable for real world applications, but it allowed us to conduct a preliminary analysis on the performances of the two techniques and to understand their capability to acquire 3D points in presence of turbidity. The performances have been evaluated in terms of accuracy and density of the acquired 3D points. Our results can be used as a reference for further comparisons in the analysis of other 3D techniques and algorithms

Mixed Prototyping for Products Usability Evaluation

Mixed prototyping is an industrial practice that combines virtual and real components in order to realize a prototype of a product used to evaluate and assess the design choices. Recently, mixed prototypes have been also used to assess the usability of products interface. This particular application arises several problems related to the devices and the interaction techniques that, better than others, allow a natural interaction with the mixed prototype. This paper presents a mixed reality environment for usability evaluation that deals with two specific problems of this kind of application: the occlusion between real and virtual objects and the interpretation of the user's gestures while he/she is interacting with the elements of the product interface. In particular we propose a technique able to manage both the problems by using only commodity hardware and video processing algorithms, thus avoiding the use of expensive datagloves and tracking devices. The proposed approach has been validated through a user study addressed to establish whether and to what extent the augmented reality devices and the techniques proposed may distort the usability assessment of the product. Moreover, the user study compares the mixed reality environment adopted in this study with a classical virtual reality set-up. Copyright © 2010 by ASME.status: publishe