bluuebunny/crossref_metadata_2025 huggingface dataset:
Recognizing Algorithm for Digitized Rotational Parts
Authors: Manolescu Alexandru , Fota Adriana , Oancea Gheorghe
Published: August 2013

It is a well known fact that Reverse Engineering techniques involve the following steps: scanning the object, pre-processing a cloud of points, processing the cloud of points, redesigning, and manufacturing the part.

Difficulties arise when processing clouds of points resulted from digitization, obtaining geometrical parameters of the scanned object itself and getting the final associated CAD model.

This paper presents an algorithm for the recognition of a rotational part form. The part has been previously scanned and will be redesigned for re-manufacturing.

To determine the surfaces of a rotational part, it is necessary to scan the part in order to obtain the cloud of points which is afterwards cleared of noise points. Beginning with the cloud of points, an algorithm is built that automatically determines the part’s axis. The axis is then used to generate the required sections. The same tool also facilitates the recognition of simple, basic shapes like cylinders, cones and spheres.

The points cloud data are stored in a text file. The text file contains all the points’ coordinates of the cloud. After running the software on the data file we obtain the geometrical data necessary for the parametric model. This data can then be exported to a 3D design environment to redesign the digitized part.

This paper contains two case studies in which a part was scanned and then, following the steps outlined above, the geometrical data of the part are obtained. With the geometrical data, the part can be modelled like a parameterized object.
Computer Support for the Identification of Solution Patterns for the Conceptual Design of Advanced Mechatronic Systems
Authors: Dumitrescu Roman , Anacker Harald , Bauer Frank , Gausemeier Jürgen
Published: August 2013

Within the last years mechatronics as a self-contained discipline doubtlessly shaped the development of technical systems. Mechatronics means the close interaction of mechanics, electronics, control engineering and software engineering in order to achieve a better systems behavior. Due to the outstanding deployment of information and communication technologies, the functionality of mechatronic systems will go far beyond the known standards with the intention to increase their robustness, flexibility and reliability. The objective is to develop intelligent systems that react autonomously on changing environmental conditions and optimize their behavior during operation. The design of such advanced mechatronic systems is a challenge. Additionally to mechanical, electrical, control and software engineers also expertise from mathematical optimization, artificial intelligence and even cognitive science is necessary. This requires an effective and continuous cooperation and communication between developers from different domains during the whole development process. As a consequence a domain-spanning methodology is necessary in order to guarantee an effective work flow between the participating developers from various domains and their domain-specific methods, terminologies and solutions. For this purpose an ontology-based computer support will be presented, that facilitates the systems engineer by analyzing the functional system model and identifying convenient solutions. This includes the generation and storage of once proven design solutions as well as the search for the effective and domain-spanning reuse.
Design and Development of an Instrument for Measurement of Biting Force in Human Beings
Authors: Vaz Anand , Jha Mayank Shekhar , Seth Rishi , Saxena Ambuj
Published: August 2013

The gnathodynamometer is a device meant for the measurement of biting force and the assessment of masticator performance. The devices reported in the literature have not been very convenient to use, and have often undergone modifications. In this paper, a systematic mechatronic approach has been followed in the design and development of a gnathodynamometer, to overcome reported inadequacies. The design problem imposes several constraints of size, access, loading, safety, hygiene, and so on. The gnathodynamometer developed in this work is designed for a maximum biting force of 600 N, and a maximum deflection of 1 mm. Design of the main component, which is the fork, has been elaborately explained. Strain gauges located at the root of the inner surface of each prong have been used to sense the strains arising due to the application of biting force. The complete electronic circuit has been designed. Readings of biting force are displayed on a digital readout. The circuit includes selection of strain gauges, design of Wheatstone bridge, preamplifier. The device is then calibrated and a relationship between applied biting force and output voltage is obtained.
Stiffness Analysis and Comparison of 3-PPR Planar Parallel Manipulators With Actuation Compliance
Authors: Wu Guanglei , Bai Shaoping , Kepler Jørgen A.
Published: August 2013

In this paper, the stiffness of 3-PPR planar parallel manipulator (PPM) is analyzed with the consideration of nonlinear actuation compliance. The characteristics of the stiffness matrix pertaining to the planar parallel manipulators are analyzed and discussed. Graphic representation of the stiffness characteristics by means of translational and rotational stiffness mapping is developed. The developed method is illustrated with an unsymmetrical 3-PPR PPM, being compared with its structure-symmetrical counterpart.
Application of Laser Technology for Measurement and Verification of Marine Propellers
Authors: Cavada Javier , Fadón Fernando
Published: August 2013

Marine propellers are geometrically complex elements, formed by multiple blades and one central hub. Their measurement during manufacturing process will determine their future performance. The state-of-the-art measurement methods used in the majority of the propeller manufacturers require physical contact between the measuring tool and the surface.

In front of these excessively rigid and inflexible mechanical system, Laser scanning offers a vast number of advantages for marine propeller measurement like high precision and small size of the equipment required, and this paper describes several practical tests carried out on real propellers.

Besides these multiple advantages, this paper identifies a remarkable list of constraints found during measuring tests, caused in principal by the high sensitivity of laser scanners to vibrations, noise, roughness, reflections and metallic particles floating in the air.

This paper concludes offering detailed recommendations for the application of laser techniques in propellers verification, as well as suggestions for further research.
Study the Effects of Different Surfactants on Hydrophilicity of Polydimethylsiloxane (PDMS)
Authors: Madadi Hojjat , Casals-Terré Jasmina
Published: August 2013

The outstanding characteristics of polydimethylsiloxane (PDMS) caused its extensive use as base material to manufacture microfluidic devices. PDMS has numerous advantages coming from instinct properties such as its low cost, simple fabrication procedure, and robust nature that make it a compatible material in many applications such as biological and biomedical engineering. In spite of favorable physical and chemical properties, hydrophobic surface of PDMS is sometimes debatable. Because of PDMS is highly hydrophobic, pumping aqueous solution through microchannels using only capillary forces might be difficult. Although many surface treatments methods have been proposed to modify and increase the hydrophilicity of PDMS [Oxygen plasma [1], UV-radiation [2], Silanization and Chemical vapour deposition [3],…], the use of surfactants is the most effective and easiest method to overcome the hydrophobicity compared to more complex protocols which require expensive facilities [4,5]. The hydrophilic behavior of surfactant-added PDMS and especially its biocompatibility has allowed many microfluidic bio-applications such as separation of biomolecules [6,7], blood cell separation [8] and cell-based assay [9,10]. This paper discusses about the efficiency of adding different surfactants on the wettability of PDMS.
Product Design Variants and Customization: Dealing With Conflicting Requirements
Authors: Hundal Mahendra
Published: August 2013

Product variety is necessary to satisfy the market. The change from a vendor market to a customer market has led to increased competition among manufacturers, benefiting the customer. Accordingly, less busy market niches are sought and more specific customer wishes are fulfilled. Rapid improvements or design of new products generate new incentives to buy. This market trend increases the variety of product variants while simultaneously leading to smaller number and lot size per variant. An increase in the number of variants and a decrease in the lot size tend to lead to longer throughput and delivery times and problems of quality assurance, and to higher direct and indirect costs per variant. The paper discusses this problem and provides a set of recommendations for controlling the multiplicity of variants within an enterprise.
Selecting Future Development Partners Through Monitoring of Existing Collaborations
Authors: Nass Susanne , Anderl Reiner
Published: August 2013

Cross-company collaboration in product development is currently faced with major challenges because of varieties of reasons. Companies depend on acquiring the know-how for innovative future products from outside the company while the support is not limited on the product development but rather on continuous collaboration over product life cycle and consequently are planned for long term normally. These development partners have to get an early and deep read into product and process design of the company for a goal-oriented cooperation. Despite these far-reaching knowledge of the development partner about the own company, the selection of a development partners is still founded on subjective criteria or random acquaintances yet. This approach uses data from ERP systems for the business view and of PDM systems representing the technical view for the monitoring of current cooperation and development partners. It becomes possible to monitor actual collaborations continuously and targeted for their suitability and also serves to gather and analyze information in order to select suitable development partners.
Application of the Flexible Link Model (FLM) and Quantum Computing-Based Algorithm for the Optimum Synthesis of Partially Compliant Mechanisms
Authors: Smaili Ahmad , Hassanieh Mazen , Diab Nadim
Published: August 2013

The purpose of this paper is to integrate the concept of the flexible link model (FLM) with a modified real coded quantum inspired evolutionary algorithm (MRQIEA) for the optimum synthesis of partially compliant mechanisms. The purpose is to synthesize the compliant and rigid members of a partially compliant mechanism in a single optimization run. The compliant member parameters are defined by the FLM which facilitates the integration of the design variables associated with compliant members and rigid links in one solution vector. Four examples are presented to demonstrate the approach.
Three-Dimensional Voronoi and Multigrid Model for Microstructure Contact Problem
Authors: Boffy H. , Sainsot P. , Baietto M. C. , Lubrecht T.
Published: August 2013

The prediction of both the tribological behaviour and mechanical analysis of the wear resistance are still of great research interest in order to improve the lifetime of material surfaces. This concerns both bulk and coated materials although coating processes have been often developed in order to protect substrates from tribological solicitations. The wear resistance of coated materials has been the subject of many studies which show that it is possible to protect and improve significantly the durability of substrates. A straightforward discretisation of the multi-scale problem of graded coatings on substrates exceed the memory and CPU capacity of current (and next generation) computers. The authors have proposed an efficient numerical model that can handle this multi-scale problem: using billion points and locally refined grids.
Simulation of a Finishing Operation: Milling of a Turbine Blade and Influence of Damping
Authors: Lorong Philippe , Coffignal Gerard , Balmes Etienne , Guskov Mikhail , Texier Anthony
Published: August 2013

Milling is used to create very complex geometries and thin parts, such as turbine blades. Irreversible geometric defects may appear during finishing operations when a high surface quality is expected. Relative vibrations between the tool and the workpiece must be as small as possible, while tool/workpiece interactions can be highly non-linear. A general virtual machining approach is presented and illustrated. It takes into account the relative motion and vibrations of the tool and the workpiece. Both deformations of the tool and the workpiece are taken into account. This allows predictive simulations in the time domain. As an example the effect of damping on the behavior during machining of one of the 56 blades of a turbine disk is analysed in order to illustrate the approach potential.
Energy Efficiency Design Method for Electrical and Electronic Equipments
Authors: Evrard Damien , Brissaud Daniel
Published: August 2013

Energy consumption during the use phase often contributes significantly to the overall energy demand and to the environmental impacts of an elect(on)ic product’s lifecycle. Therefore, regulations, standards, and customers tend to demand that the electronic industry supplies products with lesser consumption. However, manufacturers lack of systematic methods and tools to integrate energy consumption into their design projects from the early design phases.

This paper presents the Synergico method which is meant to be incorporated in the current design practices of manufacturing companies, therefore helping design more energetically efficient electr(on)ic products without compromising the other design criteria (ergonomics, performances, usage value, quality, cost, delay, etc.). This method is based on three tools to use from the earliest design phases.

Firstly, an In-Use Energy consumption indicator providing an assessment of the energy consumption during the use phase during each design phase. Thanks to the consideration of several use scenarios, it calculates values of the product’s energy consumption for each product sub-assembly, and each operating mode, thus monitoring the consumption and compliance of a product with design objectives. Secondly, a Guideline-based tool adapted to electronic products. These guidelines can easily be filtered to consider only the most relevant ones according to the context (design phase, expert concerned, scope of the guideline, etc.). Thirdly, a Lifecycle Check tool to verify that no pollution trade-offs, between life cycle phases, would hinder the design of an energy efficient product with good overall environmental performances. A case study illustrates the use and integration of the Synergico method and the way it coordinates the tools.
The Thermal Ageing Effect on Viscoplastic Behaviour of High Density Polyethylene (HDPE)
Authors: Ferhoum Rabah , Aberkane Meziane , Ould Ouali Mohand , Hachour Kamel
Published: August 2013

The degradation of polymers has a great influence on their characteristics. Two kinds of processes may be distinguished, physical and chemical. Both are strongly linked. The degradation may be for example induced by UV irradiation, thermal ageing, physico-chemical attacks (water, oxygen, etc.), and mechanical stress. To investigate the thermal ageing effect on the large deformation stress-strain behaviour of PE100, tensions tests were conducted on this material samples submitted to a temperature of 90°C during different hold times. These tests show that thermal ageing leads to an increase of the mechanical properties like the Young Modulus, the yield stress and the stress at break. We show in our work, by different investigations techniques like X-rays diffraction, Transform Infrared Spectroscopy (FTIR), that this increase of mechanical properties is not due to a chemical changes but is due to an increase of the rate of the crystallinity commonly designated by the post-crystallization phenomena.
Study of a Hydroelastic Instability Phenomenon: Flutter of Racing Yacht Keels
Authors: Balze Rémy , Devaux Hervé , Jézéquel Louis
Published: August 2013

In the field of aeroelasticity, flutter is a well known instability phenomenon. Flutter is a synchronized vibration which takes place in a flexible structure moving through a fluid medium. It occurs when two regular, rhythmic motions coincide in such a way that one feeds the other, drawing additional energy from surrounding flow. A classic case of wing flutter might combine wing bending with either wing twisting.

This article explores the flutter phenomenon in water. An important difference from the flutter phenomenon in air is the fact that the flexible structure is evolving in heavy fluid; this implies in particular added mass effects and important fluid damping.

Flutter appeared for the first time on racing yacht keels with composite fins, so in water, in 2004:

• On the IMOCA 60 feet boat POUJOULAT-ARMORLUX of Bernard STAMM during the transatlantic race ‘The Transat’: he lost his keel and capsized.

• On the IMOCA 60 feet boat SILL Rolland JOURDAIN: the keel and the boat were saved.

Following these problems — particularly following the loss of the keel of Bernard STAMM sailboat, accident that could have dramatic consequences for the skipper — HDS company focused on the phenomenon.

Flutter has occurred only for canting keels with composite fins on IMOCA 60 feet and Volvo 70 feet racing yacht. The main questions asked are “Why are composite keels susceptible to flutter, and is it possible to predict and prevent this behaviour?”, then “Can a fair indication of the flutter critical speed of the keel be given at low cost?”.

This presentation will introduce the strategy of HDS faced to the problem and the analytical and numerical methods implemented to estimate the flutter critical speed. Our model is based on a truncated modal basis for the most energetic modes which are generally, for a bulb keel, the lateral bending predominant mode and the torsion predominant mode. One of our requirements was to make a simple model in order to integrate the calculation of the flutter critical speed in the first design loops of a composite or steel keel.

This model has worked well for the two cases of flutter appeared on IMOCA sailboat keels. Besides, to verify the quality of the model and to complete our analysis of flutter phenomenon on racing yacht keels, a 3 dimensional multi-physics simulation has been developed using the software ADINA.
Adaptable Fixturing Heads for Swarm Fixtures: Discussion of Two Designs
Authors: Gagliardi Serena , Li Xiong , Zoppi Matteo , de Leonardo Luis , Molfino Rezia
Published: August 2013

Driven by the trend of life-cycle design and sustainable production, an innovative project called self-reconfigurable intelligent swarm fixtures (SwarmItFIX) funded by the European Commission is being developed. The project investigates the application of robotic multi agent fixtures for the support of automotive and airplane body panels during their manufacturing and assembly processes. This paper addresses the exploration and development of the adaptable heads, which are the end-effector of the intelligent fixture. The head is able to adapt to the shape of the workpiece and freeze its shape after adaptation to provide stable support. Two kinds of head designs are discussed. The first design uses the pseudo-phase-change properties of a volume of bulk grains (metal sand) which can be clustered using a hydrostatic pressure to conform to a given workpiece shape. The second design investigated uses phase-change magneto-rheological (MR) fluid in a network of channels to allow and block the motion of a crown of miniature pistons. The initial experiments are carried out and their results show the effectiveness of the design.
Walking Trajectory Optimization With Rotation of the Feet for a Planar Bipedal Robot With Four-Bar Knees
Authors: Hamon Arnaud , Aoustin Yannick
Published: August 2013

The design of a knee joint is a key issue in robotics and biomechanics to improve the compatibility between prosthesis and human movements and to improve the bipedal robot performances. We propose a novel design for the knee joint of a planar bipedal robot, based on a four-bar linkage. The dynamic model of the planar bipedal robot is calculated. We design walking reference trajectories with double support phases, single supports with a flat contact of the foot in the ground and single support phases with rotation of the foot around the toe. During the double support phase, both feet rotate. This phase is ended by an impact on the ground of the toe of one foot, the other foot taking off. The single support phase is ended by an impact of the swing foot heel, the other foot keeping contact with the ground through its toe. For both gaits, the reference trajectories of the rotational joints are prescribed by polynomial functions in time. A parametric optimization problem is presented for the determination of the parameters corresponding to the optimal cyclic walking gaits. The main contribution of this paper is the design of a dynamical stable walking gait with double support phases with feet rotation, impacts and single support phases for this novel bipedal robot.
Identification and Modeling of Variability in Fabrics Used as Reinforcement in Polymer Composites: Influence on Transport and Mechanical Properties
Authors: Binetruy Christophe , Comas-Cardona Sébastien , Zhang Fan
Published: August 2013

Variability in fiber architecture and content introduces randomness in transport and mechanical properties of textile reinforcements and composites. Assessment of robustness of both manufacturing processes and composite parts require to link fabric variability to dominant properties. Irregular injection flow patterns or defects in the final products often occur due to the high variability in the fibrous media. Therefore, manufacturing robustness and part reliability have to be studied to avoid trial and error procedures. This study focuses on spatial variability in the fiber volume fraction and architecture and their influence on permeability of fiber reinforcements and mechanical performance of textile composite, relating these important properties to variation in reinforcement architecture. Methods to capture experimentally and model numerically the fabric randomness are presented and illustrated on typical non-woven fabrics. An efficient numerical approach is presented for the simulation of mold filling process with random fibrous permeability as input. Numerical examples for different injection schemes are presented to demonstrate the ability of the current approach in predicting the variability in mold filling results.
Functionally Graded Material (FGM) Parts: From Design to the Manufacturing Simulation
Authors: Muller Pierre , Mognol Pascal , Hascoet Jean-Yves
Published: August 2013

Recent developments in additive manufacturing processes add opportunities to manufacture metallic parts. One of major recent evolutions of additive manufacturing is the ability to produce parts with functionally graded materials (FGM). These materials can be characterized by the variation in composition and structure gradually over the volume. The use of these materials is particularly attractive in fields such as aeronautical or biomedical where the multi-material parts allow modifying locally mechanical, chemical, physical or biochemical properties. Today, main of parts with FGM which are manufactured with these processes are not functional, with simple morphology, small dimensions and discrete multi-material repartition. To move from these samples to functional parts it is necessary to have a global control of the process used. It includes the control of all parameters — laser power, powder and gas flow rates, axis motions — and a manufacturing with an optimal strategy. A methodology to manufacture multi-material complex parts is proposed so as to have this global approach.
Consideration of the Manufacturing Trajectories in a Global Design for Additive Manufacturing Methodology
Authors: Ponche R. , Kerbrat O. , Mognol P. , Hascoet J. Y.
Published: August 2013

Additive Manufacturing (AM) is a new way of part production which opens up new perspectives of conception as mass and cost reduction and increase of functionalities. However these processes have their own characteristics which as for all the manufacturing processes have a direct impact on the manufactured parts quality. Especially, because the manufacturing trajectories have a influence on the physical phenomena during the process, they have also a strong impact on the quality of the produced parts in terms of geometry.

In this paper, the choice of manufacturing trajectories and their impacts on the final shape and quality of the parts is integrated into a global Design For Additive Manufacturing (DFAM) methodology which allows to move from functional specifications of a design problem to a proposition of an adapted part for AM processes.
Influence of Layer Thickness on the Properties of Multifunctional Tribological Coatings
Authors: Lara Luciano de Oliveira Castro , Costa Henara Lillian , de Mello José Daniel Biasoli
Published: August 2013

Multifunctional coatings, widely used in tribological applications, have their properties strongly influenced by the interaction of the system coating/substrate. The use of multi-layered coatings has been pointed out as a solution for the problem of high internal stresses that can be generated in coated systems, in particular in the case of soft substrates. In multilayered coatings, a decrease in the stress gradient between substrate and coating improves adhesion. Moreover, the thickness of the coating has shown a strong influence on the tribological behavior of the coated system. This paper, through widely used and efficient techniques, seeks to assess the influence of the thickness of different layers (DLC and CrN) on the response of a multifunctional coating. Si-rich DLC and CrN multi-layered coatings with different thicknesses were deposited on a steel substrate (AISI 1020) by Plasma Enhanced Magnetron Sputtering (PECVD). Scanning electron microscopy (SEM) and Raman spectroscopy (RS) were used in order to characterize the chemical composition and microstructure of the coatings. Instrumented indentation and scratch test techniques were used to measure hardness, elastic modulus, and adhesion of each layer. Critical loads were determined by visual analysis, using SEM in conjunction with the curves obtained in the scratch tests. The evaluation of the effect of the thicknesses of the layers allowed an optimized design of the multifunctional coated systems with improved durability.
A New Integration Framework for Modeling and Optimizing Systems in Preliminary Design Phase
Authors: Matar Jad , Chenouard Raphael , Bernard Alain
Published: August 2013

In this paper we propose a new integration framework model for simplifying the feasible space exploration and product optimization in early design phases. Hence, modeling and optimizing tasks are core activities in this framework. Currently, system engineering problems are modeled and optimized using a wide range of domain-specific languages. One should not duplicate these languages by creating a new system engineering language capable of modeling and optimizing every aspect of a system. Thus we combine the UML2 language and the formalism of Constraint Optimization Problems (COPs). UML2 is a visual modeling language, which provides a set of diagrams and constructs for modeling the major aspects of a product. In order to optimize design parameters, we reformulate some of this modeling knowledge into a COP. A COP may be defined as a regular constraint satisfaction problem (CSP) augmented with a set of objective functions. Thus the optimization problem to be solved is stated declaratively with acausal constraints. Then, COP solvers are based on generic solving algorithms computing a set of optimal solutions. In this paper, generic concepts integrating variability modeling concepts and based on architecture description languages are introduced. We also briefly describe transformation strategy using ATL language to perform a bidirectional mapping between UML2 constructs and the corresponding COP models.
Vibration-Assisted Grinding of Mild and Hardened Steel: A Novel Design Vibrating Jig and Process Performance
Authors: Tsiakoumis Vaios , Batako Andre
Published: August 2013

Grinding is always one of the most significant processes in manufacturing sector due to its high precision and accuracy and especially nowadays where the demand for higher quality products has been raised. Its importance lies on the fact that it stands at the final stages of a component’s manufacturing chain and therefore, the possibility of errors must be at the lowest levels. Heretofore, the improvement of this process has motivated a number of researchers to develop different techniques. In the current work a novel method of vibration-assisted surface grinding of mild and hardened steel using aluminium oxide grinding wheels is examined. More specifically, the design concept along with the dynamic characteristics of a simplified vibrating jig is presented. The purpose of this jig was to accommodate and oscillate the workpiece at a certain frequency during surface grinding in order to improve the performance of the process in terms of achieving lower grinding forces and thus lower power consumption, higher material removal rates and better product surface finish. Two grinding wheels and two workpiece materials with different properties were employed during conventional and vibration-assisted surface grinding and the results are compared. The benefits of this non-conventional, advanced grinding process are also illustrated.
Effect of Axial Preload on Double-Lap Bolted Joints: Numerical Study
Authors: Benhaddou Taha , Stephan Pierre , Daidie Alain , Chirol Clément , Tuery Jean-Baptiste
Published: August 2013

This paper presents the numerical study of double-lap bolted joint behavior. This type of joint is mainly used in aeronautical structures to transfer the given loads (by both adhesion and by deformation-shearing). Recent articles, based on experimental fatigue tests conducted by AIRBUS, have shown the beneficial effects of preloading on the fatigue life of these joints.

Finite element analyses were performed using ABAQUS® to study the behavior of a double-lap single-bolted joint with different plate thicknesses (joint thickness = 0.5d, 1d, 1.5d, 2d 2.5d, 3d, 3.5d and 4d, where d is the bolt diameter).

The numerical model provides several important results. In the case of static loads, elasto-plastic constitutive laws of the bolt and the plate materials allowed the process to be simulated on the basis of tension tests.

Mechanical aspects of this type of assembly are numerically identified; from the initial state of adhesion to the state of plastic deformation of parts in contact including the stage of generalized slippage. We note that the fracture load increases slightly when the bolted joint is preloaded while the failure area remains the same. In the case of large plate thickness, the connection is subjected to significant bending stresses and this involves strong local plasticization associated with the loss of preload.

In the case of cyclic loading, we consider a numerical model based on the simulation of one loading/unloading cycle. A noticeable decrease in initial preload is observed for certain configurations, in particular those with the largest plate thickness. This phenomenon is related to the effect of strain hardening of the bolt during the first loading cycles. Some experimental work by AIRBUS has shown that the fatigue life of assemblies is dependent on the material plate thicknesses.

An extension to the case of a multiple-bolted joint (three rows of three bolts) is finally discussed and highlights the evolution of the rate of load transmission with respect to the applied load.
A Knowledge Capitalization Methodology Based on Automatic Knowledge Extraction From 3D CAD Models
Authors: Lebouteiller Mathieu , Boxberger Jérémy , Gomes Samuel , Lebaal Nadhir , Schlegel Daniel
Published: August 2013

The issue of improving quality, costs and delays indicators in design and manufacturing is more relevant than ever in the industry. After lean manufacturing, well known in production process, the lean engineering approach is being implemented today in the field of design, taking the name of lean product development.

The management of knowledge and know-how (existing, new or to be acquired) is the heart of lean engineering. In our suggested methodology this is implemented through a new generation of tools called Knowledge Configuration Management (KCM) and Knowledge Extraction Assistant (KEA).

KCM tools are lean engineering components that provide analytical approach to knowledge management and knowledge-based engineering. These tools require a highly integrated approach that involves, for example, predefined geometrical parametric 3D models, such as CAD templates. But this approach cannot be deployed in all engineering sites.

We propose to complete this KCM approach introducing a semantic network approach, coupling with Feature Identity Card (FIC). FIC contains a set of metadata and information existing in the Product Data Management (PDM), connected with information extracted from 3D CAD (Computer Aided Design) models. It allows contextualizing information and ensures semantic connections, in order to manipulate the right parameters with mathematical algorithms. Those algorithms will search candidate relationships between design parameters extracted from CAD models.

Our suggested approach aims at extracting knowledge in cases where design never came out of Knowledge Based Engineering (KBE) applications. In those situations, it seems important to complete classical knowledge management approach, and to find out the implicit knowledge embedded in 3D CAD models. This is achieved through a global approach, focusing on the product’s 3D definitions.

We suggest introducing the latter approach by a suite of digital KEA tools (interfaced with KCM tools). Extracting knowledge from projects information stored in the Product Data Management does this.

More precisely, the methodology is based on a commercial 3D similarity search tools for CAD models and on mathematical algorithms that search relationships between extracted design parameters. The goal is to submit new rules to the process and design experts.

Implementing this methodology, a deeper knowledge of the product and its associated process can be acquired. This ensures a more productive and efficient design process.
Intelligent Reverse-Engineering Segmentation: Automatic Semantic Recognition of Large 3D Digitalized Cloud of Points Dedicated to Heritage Objects
Authors: Laroche Florent , Lefèvre Daniel , Servières Myriam , Hervy Benjamin , Bernard Alain
Published: August 2013

In this article we present a multidisciplinary experimentation realized between a mechanical laboratory, a computer scientist laboratory and a museum.

Our goal is to provide automatic tools for non-expert people who want to use 3D digitized elements. After scanning an objet, we obtain a huge amount of points. In order to manipulate it, it is necessary to decimate it. However, when doing this operation, we can optimize the algorithms for creating semantic topology; obviously we can do it automatically. Consequently, we are going to do what we name segmentation: we extract meaning from 3D points and meshes.

Our experimentation deals with a physical mock-up of Nantes city that have been designed in 1900. After digitalization, we have created a software that can:

1. use the whole 3D cloud of points as an input;

2. fill a knowledge database with an intelligent segmentation of the 3D virtual models: ground, walls, roofs…

This use case is the first step of our research. At the end, we aim to deploy our method to complex mechanical parts. Nowadays, when designing CAD parts we use as well as volume parts than surface parts or meshes. We know is it not necessary to reconstruct all the triangles. It is a lost of time and we can directly use cloud of points for CAD design. However, the design tree will not be updated. So, with our method, imagine that one day we can digitalize a motor and a system could automatically create the 3D mock-up and the design tree.
Objective Assessment of Surgical Skills
Authors: Cifuentes Jenny A. , Pham Minh Tu , Moreau Richard , Prieto Flavio , Boulanger Pierre
Published: August 2013

Minimally Invasive Surgery (MIS) has definitively changed the procedures performed in operating rooms. In many cases, MIS has become the recommended standard technique, replacing the traditional open surgery. Effective training and objective assessment of surgeons in these techniques become a major concern in hospitals in recent years, encouraged primarily by patients and a society that demands safer surgical procedures, which is associated with better surgeons training. In the framework of surgery, the difficulty of defining objective metrics for performance evaluation lies in the strict dependency between tasks and the difficulty of defining the meaning of optimal performance, related to the characterization of gestures made by the experts. An objective method to compare 3D gestures between an expert and novice surgeons through multidimensional data analysis is proposed in this paper. A survey of different algorithms for surgical gestures analysis in time domain is carried out. These ones include the Multi-dimensional Dynamic Time Warping (MD-DTW) and Multi-Dimensional Derivative Dynamic Time Warping (MD-DDTW). Simulation and experimental results are given with this different techniques.
Knowledge Based Reverse Engineering Methodology
Authors: Remy Sébastien , Laroche Florent , Durupt Alexandre , Bernard Alain
Published: August 2013

In Reverse Engineering, commercial solutions such as Geomagic™ or RapidForm™ or CAD software such as CATIA™ provide very efficient toolboxes that enable to rebuild geometry. Moreover, some of them provide segmentation algorithms, sketchers and/or many other facilities rebuilding tools in order to help to recover the original surface. Those software’s enable to rebuild the geometry of a technical object as a set of functions (protrusion, revolution, sweep…), they enable to add colours and textures, and they enable realistic kinematical animation and many other things. Unfortunately, all those toolboxes present a lack of geometry analysis tools. The geometry of a given product is the consequence of a complete process, it is important, considering Reverse Engineering activities, to try to recover any evidence of its past life (including socio-economical aspects, the design intents of the former designer, its different uses…) from its geometry in order to produce a good quality 3D model. Such models can provide important possibilities for Reverse Engineering. It enables to study the product more efficiently than a geometrical model based on a mesh or on free form surfaces.

This paper proposes approaches and methodologies for using knowledge to rebuild CAD model to the best closer to the original CAD model that could have been obtained by the original designer. Such a model is feature based. They can be functional features or manufacturing features. For a good rebuilt of 3D model, the geometry of these features is driven by parameters, rules and relationships that are provided by the former designer.
A Fluid-Structure Case Study in Simulation Lifecycle Management
Authors: Kibamba Yannick , Derigent William , Eynard Benoît
Published: August 2013

This paper aims at presenting an approach to structuring interactions within product, through a graph, for simulation purposes. This approach has been developed for specific needs on Simulation Lifecycle Management (SLM) dedicated to aircraft engine development. The paper also illustrates the implementation of this approach on a case study which concerns a compressor design.
Survey on Configuration Management of Modular Mechatronics Products
Authors: Li Jing , Tong Shurong , Bricogne Matthieu , Troussier Nadège
Published: August 2013

Configuration management of modular mechatronics products is an effective way of rapid development for the modular mechatronics industry. By summarizing the relevant literature, the concept of product configuration is illustrated. Then this article sums up the latest research progress for configuration design process modeling, configuration knowledge management, implementation method for configuration management methods. Finally, the weak aspects of present research are discussed, and the following research topics are determined.
Study of Thermo-Physical Properties of Selected Nickel-Based Superalloys With Use of DTA Method
Authors: Dobrovska Jana , Zla Simona , Kavicka Frantisek , Smetana Bedrich , Vodarek Vlastimil
Published: August 2013

The presented paper deals with study of thermo-physical properties of cast complex alloyed nickel based superalloys IN713LC, IN738LC and IN792-5A. In this work the technique of Differential Thermal Analysis was selected for acquisition and comparison of the phase transformation temperatures. The samples taken from superalloys in as received state were analysed at heating and cooling rates of 1, 5, 10, and 20 K/min using the experimental system Setaram SETSYS 18TM. Moreover, the transformation temperatures for zero heating/cooling rate were calculated. Based on a comparison of these temperatures it is possible to make the following conclusions: (i) The alloy IN792-5A has the highest temperature of solubility of the strengthening phase γ′ (1235°C); (ii) the highest liquidus temperature (heating) obtained by extrapolation was found in the alloy IN713LC (1349°C), the lowest solidus temperature (heating) was found for the alloy IN738LC (1212°C); (iii) At cooling an undercooling occurred in all alloys. In general it may be stated that the biggest under-cooling (TS, 47°C) was recorded in the alloy IN792 5A; (iv) The width of the interval of the heat treatment window was the biggest in alloy IN713LC (44°C); (v) The alloy IN738LC is characterised by the widest interval of melting (124°C) and solidification (134°C), while the alloy IN792 5A has the narrowest interval of melting (82°C) and at the same time almost the same interval of solidification as the alloy IN738LC (129°C); (vi) The obtained phase transformation temperatures were compared with the values of phase transformations temperatures calculated on the basis of established relationships. In order to obtain more precise description of the behaviour of Ni-based superalloys, during controlled heating/cooling of the initial material (as received state) during DTA analyses, all the samples of superalloys were subjected to a phase analysis using scanning electron microscopy. The course of phase transformations, in all the studied superalloys (IN713LC, IN738LC, IN792 5A) is likely to run according to the following reaction scheme (L = melt): L ↔ γ, L ↔ γ + MC, L ↔ γ/γ′, L ↔ γ + minority phases (such as M3B2, phase η), γ ↔ γ′.
Analysis of the Dynamic Performance of Multibody Mechanical Systems With Multiple Lubricated Revolute Joints
Authors: Haroun A. F. , Megahed S. M.
Published: August 2013

In this work a method is proposed for modeling and simulation of multibody mechanical systems with multiple lubricated revolute joints with the aid of CAD and dynamic simulators softwares. The hydrodynamic forces produced between joint components due to lubrication are obtained by integrating Reynolds’ equation that is used for evaluating the fluid pressure distribution in the journal–bearing joint. The resulted force equations are combined with Hertz contact model to make a complete model for lubricated revolute joints. This model is used with the aid of SolidWorks/CosmosMotion software package to simulate multibody systems with multiple lubricated revolute joints and a computational algorism is developed in the frame of multibody dynamics methodology. A slider–crank mechanism with two lubricated revolute joints is used as an application example to demonstrate the efficiency and versatility of the proposed method. The simulation results point out that the introduction of a lubricant at the joint clearance makes the performance of the mechanism so close to that of the ideal mechanism that does not suffer from the clearance problem, as well as improves the overall system performance.
Computer Simulation-Based Modeling of the Pharmaceutical Intervention of Postmenopausal Osteoporosis by Denosumab
Authors: Scheiner Stefan , Pivonka Peter , Smith David W. , Dunstan Colin R.
Published: August 2013

Postmenopausal osteoporosis (PMO), leading to a higher bone fracture risk, is characterized by a significantly increasing bone porosity. Recently, denosumab, which is able to efficiently interfere with bone resorption, has been approved for the treatment of PMO. In order to optimize the design of drug administration regimes, we propose a computational methodology, based on mechanistic mathematical modeling of bone remodeling, considering the governing biochemical and biomechanical regulation mechanisms, and the targeted action of denosumab. The time-dependent serum concentration of denosumab, obtained from a pharmacokinetics model, is fed into a bone cell population model, allowing for prediction of porosity evolution in PMO patients. In order to account for the mechanobiology of bone remodeling, we utilize the concept of continuum micromechanics, which accurately provides the actual (microscopic) strain state of the investigated bone. Finally, different drug administration regimes are simulated, and their effect on the bone microarchitecture is discussed.
Evaluation of CT‐based lean‐body SUV
Authors: Hamill James J. , Sunderland John J. , LeBlanc Amy K. , Kojima Cheryl J. , Wall Jonathan , Martin Emily B.
Published: August 2013

Purpose:

The authors introduce a novel method for defining standardized uptake values (SUVs) in PET/CT based on routinely collected CT data. The goal of the study is to reduce, if possible, the variability of SUV in a heterogeneous population. Two well established methods for defining SUV are based on body weight (BW) and lean body mass, calculated as a function of height, weight, and sex with an empirical formula (LBM). The authors investigate two novel models, CT1 and CT2, that estimate the lean mass from CT Hounsfield Unit values. The authors compare the four methods, assessing the variability of hepatic SUV in18F‐FDG studies.

Methods:

CT images from 252 cancer patients were segmented into regions representing lean tissues, fat, and bone. The fraction of lean tissue in the scanned region was extrapolated to the entire body with a naive method (CT1) and a method that modeled typical FDG uptake patterns (CT2). For each method, SUV‐based measurements of the liver were calculated for all patients and dependence on body weight was assessed. Coefficients of variation (CVs) were evaluated. Several sub‐cohorts were analyzed, including those with low and high body mass index (BMI). The extrapolation technique was tested in 19 melanoma patients who received head to toe PET/CT scans. CT‐based weight predictions were compared with actual patient weight in melanoma studies and in PET/CT scans of pigs.

Results:

Only the SUV based on BW method depended significantly on body weight. CVs for the BW, LBM, CT1, and CT2 methods were, respectively, 18.0%, 15.5%, 15.9%, and 14.9%. In the high‐BMI cohort, CVs were 18.2%, 16.2%, 16.2%, and 15.1%. Mean SUV of the 14 most obese patients agreed most closely with mean SUV of 120 lean patients when the CT2 method was used. SUV based on truncated CT agreed with head to toe predictions within 5% for the CT1 method and 1% for the CT2 method. CT‐based weight estimate recovered 97.4% of the weight in head to toe studies of humans and 99.7% in pig studies.

Conclusions:

The novel CT1 and CT2 methods were less variable than the BW method and were comparable to the LBM method. SUV were little affected by missing CT data.