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The hydrosoluble salts are one of the products used for the treatment in depth of the wood that come using for decades with excellent results. Nevertheless, realized investigations, principally with CCA, for Cross, J. and Bailey, G. (1989), among others, demonstrates that it can be corrosive for the metallic fasteners used in the construction in wood, because of some of the chemical products that they contain and the protection system with which Autoclave is applied.In Spain, the Real Decreto 1406/1989, that prohibits the marketing and the use of compounds of arsenic from 30/06/2004, except exceptions, has forced to the companies to replace definitively the products used up to this moment that were containing toxic substances as the chrome and the arsenic (CCB, CCA, etc.) for products consisted of other not toxic substances, as the ACQ (salts of quaternary ammonium). Of these new products scanty information is had on their behaviour and specially, on their compatibility with the metals which are made the fasteners used for the current construction in wood.This work does a comparative study of the corrosive behaviour of three hydrosoluble protectors (CCA, CCB and ACQ) towards different metals (galvanized steel and stainless steel). The evaluation has been realized across the result of a test of accelerated corrosion in the short time in artificial atmosphere of rapid corrosion. The conclusions of the work lead to affirm that the treatments of wood hydrosolubles accelerate the speed of corrosion of the metals, though with some differences between them. Las sales hidrosolubles son uno de los productos empleados para el tratamiento de la madera en profundidad que se vienen utilizando desde hace décadas con excelentes resultados. Sin embargo, investigaciones realizadas, principalmente con CCA, por Cross, J. & Bailey, G. (1989) entre otros, demuestran que pueden ser corrosivas para los herrajes metálicos empleados en la construcción en madera, a causa de algunos de los productos químicos que contienen y el sistema de protección con el que se aplican -Autoclave-.En España, la entrada en vigor del Real Decreto 1406/1989 prohíbe la comercialización y el uso de compuestos de arsénico desde el 30/06/2004, salvo excepciones. Esto ha obligado a las empresas a reemplazar definitivamente a productos utilizados hasta ese momento que contenían sustancias tóxicas como el cromo y el arsénico (CCB, CCA, etc.) por productos compuestos de otras sustancias no tóxicas, como el ACQ (sales de amonio cuaternarias). De estos nuevos productos se tienen escasos datos sobre su comportamiento y en concreto, sobre su compatibilidad con los metales con los que están fabricados los herrajes utilizados para la construcción actual en madera.Este trabajo hace un estudio comparativo del comportamiento corrosivo de tres protectores hidrosolubles (CCA, CCB y ACQ) hacia distintos metales (acero galvanizado y acero inoxidable). La evaluación se ha realizado a través del resultado de un ensayo de corrosión acelerada a corto plazo en atmósfera artificial de corrosión rápida. Las conclusiones del trabajo llevan a afirmar que los tratamientos de madera hidrosolubles aceleran la velocidad de corrosión de los metales, aunque con algunas diferencias entre ellos.

Arterial stenosis is a high-risk disease accompanied by large amounts of calcified deposits and plaques that develop inside the vasculature. These deposits should be reduced to improve blood flow. However, current methods used to reduce stenosis require externally-controlled actuation systems resulting in limited workspace or patient risks. This results in an unexplored preference regarding the revascularization strategy for symptomatic artery stenosis. In this paper, we propose a novel internally-actuated solution: a magnetic spring-loaded rotablation catheter. The catheter is developed to achieve stenosis-debulking capabilities by actuating drill bits using two internal electromagnetic coils and a magnetic reciprocating spring-loaded shaft. The state-space model of the catheter is validated by comparing the simulation results of the magnetic fields of the internal coils with the experimental results of a fabricated prototype. Contact forces of the catheter tip are measured experimentally, resulting in a maximum axial force of 2.63 N and a torque of 5.69 mN-m. Finally, we present interventions in which the catheter is inserted to a vascular target site and demonstrate plaque-specific treatment using different detachable actuator bits. Calcified deposits are debulked and visualized via ultrasound imaging. The catheter can reduce a stenosis cross-sectional area by up to 35%, indicating the potential for the treatment of calcified lesions, which could prevent restenosis.

Master of Science Pallets are used all over the world in the field of distribution. The strength values associated with a pallet have been thoroughly investigated by many different researchers; however, the stiffness values associated with pallet joints have not. The goal of this work was to investigate the stiffnesses associated with pallets joints made with lag screws and carriage bolts. It is important to understand that different materials, fastening methods, and design considerations can have a huge impact on the stiffness of the joint. This paper will discuss the various tests that were used to measure the actual stiffness of pallet joints and the results of those tests. Afterwards, the researchers detail their attempt to predict the stiffness using an equation created from the actual test data. Finally, by understanding the effects of these various factors, better pallet designs can be created that are both safer and stronger using the investigated alternative fasteners.

This article investigates the development of the following material properties of concrete with time: compressive strength, tensile strength, modulus of elasticity, and fracture energy. These properties were determined at seven different hydration ages (18 h, 30 h, 48 h, 72 h, 7 days, 14 days, 28 days) for four pure cement concrete mixes totaling 336 specimens tested throughout the study. Experimental data obtained were used to assess the relationship of the above properties with the concrete compressive strength and how these relationships are affected with age. Further, this study investigates prediction models available in literature and recommendations are made for models that are found suitable for application to early age concrete. Results obtained indicate that the relationship between the splitting tensile strength and concrete compressive strength can be approximated with a power function between 0.7 and 0.8, and this correlation is not affected by age. Fracture energy of the concrete and modulus of elasticity values obtained in this study correlate well with the square root of the compressive strength and it was found that this relationship holds true for all hydration ages investigated in this paper. Inverse analysis on the wedge-splitting test was conducted to determine the direct tensile strength. Values of tensile strength obtained from the inverse analysis have been validated numerically by carrying out finite element analysis on the wedge split, and anchor pull-out tests. The ratio of the tensile strength obtained from the inverse analysis to the splitting tensile strength was found to be in the range of 0.5&ndash, 0.9 and 0.7 on average.

This paper presents a polymer micromachined transmission from small translational displacement to large rotational displacement, which has the potential for further miniaturizing a variety of micro robot applications such as insect-inspired flapping wing nano air vehicles (FWNAVs). Innovative claims include (1) the transmission mechanism using a geometrically nonlinear bending, (2) the microfabrication process consisting of only the standard steps such as the deposition, the photolithography, the curing, and the release without any post-assembling, and (3) the stroke angle of about 40° without any dynamic effect., 15th IEEE Int’l Conference on Nano/Micro Engineered & Molecular Systems (IEEE-NEMS 2020), September 27-30, 2020, San Diego, CA, USA （新型コロナ感染拡大に伴い、現地開催中止）

In this paper, an experimental investigation is presented for sandwich panels with various core layer materials (polyisocyanurate foam, mineral wool, and expanded polystyrene) when subjected to a justified blast load. The field tests simulated the case for when 5 kg of trinitrotoluene (TNT) is localized outside a building’s facade with a 5150 mm stand-off distance. The size and distance of the blast load from the obstacle can be understood as the case of both accidental action and a real terroristic threat. The sandwich panels have a nominal thickness, with the core layer equal 100 mm and total exterior dimensions of 1180 mm × 3430 mm. Each sandwich panel was connected with two steel columns made of I140 PE section using three self-drilling fasteners per panel width, which is a standard number of fasteners suggested by the producers. The steel columns were attached to massive reinforced concrete blocks via wedge anchors. The conducted tests revealed that the weakest links of a single sandwich panel, subjected to a blast load, were both the fasteners and the strength of the core. Due to the shear failure of the fasteners, the integrity between the sandwich panel and the main structure is not provided. A comparison between the failure mechanisms for continuous (polyisocyanurate foam and expanded polystyrene) and non-continuous (mineral wool) core layer materials were conducted.

A consortium study, Energy Resistance of Commercial Roofs, was developed by the National Research Council Canada (NRC) with support from roofing contractor associations, roofing and accessories manufacturers, insulation manufacturers, and roofing consultants to develop scientifically supported performance data on energy resistance of roofing systems that are constructed according to field practices. This study has two major tasks. This paper presents and discusses the results from Task 1, in which 36 roofing assemblies representing seven climatic zones in North America were designed and tested to evaluate their effective thermal resistance and to validate their performance relative to the code requirements. The test matrix comprised mechanically attached roofing system, partially adhered roofing system, and adhesive applied roofing system designed with three different insulation types—polyisocyanurate, expanded polystyrene, and stone wool. The test protocol involved measurement of the thermal resistance of the insulation component and effective thermal resistance of the roofing assemblies at four different mean temperatures representing a very cold climate to solar-heated climatic conditions. All the testing was conducted at NRC's Dynamic Roofing Facility–Energy. The experimental research highlighted two influencing parameters that are currently not considered in the energy design of the roof. One is the temperature dependency performance of insulation and its impact on the effective R-value, and the second is the thermal bridging of fasteners. The measured data showed a decreasing trend of the effective R-value with increasing fastener density. The combined effect of insulation performance and thermal bridging lowered the effective R-value of some of the tested assemblies by 2% to 20% below the target design values. The current design practice needs to acknowledge the thermal bridging effects of fasteners and plates and accommodate them appropriately at the design stage of the roofs. Excluding this could lead to repercussions on the overall energy performance of the roof., 9th Symposium on Roofing Research and Standards Development, December 8, 2019, Houston

[EN] The objective of this paper is to use electromagnetic-based computer-aided design (CAD) tools to investigate the maximum tuning range of channel filters, typically used in satellite payloads. Both circular and rectangular waveguide technologies are investigated. The results of the investigation show that single-mode rectangular waveguide implementations offer substantially wider tuning range, as opposed to classical dual-mode circular waveguide implementations. In addition to simulations, measurements are also presented indicating very good agreement with theory, thereby fully validating the CAD procedure., This work was supported in part by MINECO (Spanish Government) under Research and Development Project TEC2016-75934-C4-1-R and in part by Research and Development Technicians under Grant PTA2015-10839-I.

The safety of buildings located in seismic zones is related to the proper design of both the structural and the non-structural components. In recent seismic events, the collapse of the non-structural parts clearly demonstrated how they may represent a risk not only for the life safety but also the majority of the economical losses. Light cladding panels are a common solution to built facades in framed systems with rigid infills, particularly in reinforced concrete structures with masonry walls. They are usually fixed to the supporting structures by means of plastic anchors through angle brackets. Within this context, an experimental campaign was carried out to investigate their behaviour under seismic action. Starting from dynamic tests on real size facades, a new test protocol was proposed for the assessment of plastic anchors for fixing facade claddings. The scope of the present paper is to provide a theoretical background for the aforementioned test protocol.

I dagsläget finns ingen bearbetad beräkningsmodell för fästplåtar enligt Eurokod. Syftet med detta examensarbete är att utforma en fungerande och lättförståelig beräkningsmodell för dessa fästplåtar. Arbetet har begränsats till fästplåtar med fyra och sex förankringar bestående av varmvalsat stål samt armeringsstänger som förankring. Beräkningsmodellen är uppbyggt med hjälp av studier på gamla beräkningar samt nya aspekter som anses vara relevanta som sedan översatts till Eurokod. Fästplåten har analyserats utifrån normalkraft, tvärkraft och moment samt samverkan mellan dessa krafter. Varje ingående konstruktionsdels kraftkapacitet har kontrollerats och sedan sammanställts till en totalt tillåten kraft. För att ytterligare underlätta beräkningsmodellen har ett beräkningsprogram i Excel utarbetats. För att slutligen verifiera beräkningsmodellen har verkliga tester utförts. In the current situation there´s no finished analytical model for fasteners according to Eurocode. The purpose of this paper is to develop a workable and comprehensive analytical model for these fasteners. The paper has been limited to fasteners with four and six anchors consisting of hot rolled steel and steel bars as anchorage. The analytical model is built with support from old calculations and new aspects considered relevant and then translated into Eurocode. The fasteners have been analyzed for normal force, shear force and moment, also the interaction between these forces have been taken into account. The force capacity of each detailed part has been checked and converted into a total force. To make the analytic model even easier to follow a computational program in Excel been designed. Real test were made to finally verify the analytical model.

Kernel-based methods for support vector machines (SVM) have shown highly advantageous performance in various applications. However, they may incur prohibitive computational costs for large-scale sample datasets. Therefore, data reduction (reducing the number of support vectors) appears to be necessary, which gives rise to the topic of the sparse SVM. Motivated by this problem, the sparsity constrained kernel SVM optimization has been considered in this paper in order to control the number of support vectors. Based on the established optimality conditions associated with the stationary equations, a Newton-type method is developed to handle the sparsity constrained optimization. This method is found to enjoy the one-step convergence property if the starting point is chosen to be close to a local region of a stationary point, thereby leading to a super-high computational speed. Numerical comparisons with several powerful solvers demonstrate that the proposed method performs exceptionally well, particularly for large-scale datasets in terms of a much lower number of support vectors and shorter computational time.

This paper presents compliant transmission mechanisms for a flapping-wing micro air vehicle. The purpose of this mechanism is to reduce power consumption, a critical issue in this kind of vehicles, as well as to minimize the peak input torque required by the driving motor, which helps to maintain flight stability and reduces mechanical shocks of the structure. We first describe the development of pseudo-rigidbody model of the mechanism and the analysis of the corresponding kinematics. Second, we compute the required input torque for driving stable flapping motions, from the perspectives of work and energy. For this computation, two methods are applied, one based on the principle of virtual work and another one based on rigid-body dynamics. Our mathematical analysis demonstrates that both methods are consistent with each other in terms of the resulting input torque from the motor. Finally, according to the results from the input torque analysis, the main parameters characterizing the compliant joints, the torsional stiffness of virtual spring and initial neutral angular position, are optimized. The experimental results carried out with two different mechanical setups, one with rigid components, and another one with flexible components, demonstrate the relationship between the input voltage (that is directly related to flapping frequency) and power saving of the compliant mechanism. The average power consumption is reduced of up to 4%, and peak power consumption is reduced up to 25% using the compliant transmission mechanisms compared to the rigid mechanism. The experiments also show a clear relationship between flapping frequency and power savings., The work of C. Zhang was supported by the China Scholarship Council (CSC). The work of C. Rossi was supported in part by the RoboCity2030-III-CM Project (S2013/MIT-2748, Robotica aplicada a la mejora de la calidad de vida de los ciudadanos, fase III), through the Programas de Actividades I+D en la Comunidad de Madrid, and in part by the Structural Funds of the EU.

Compliant mechanisms can be reconfigured with variation of compliance performance, by changing the positions of each compliant module thereof within its position space. This paper synthesizes the compliance of two types of parallelogram mechanisms by changing the positions of compliant joints within their position spaces. Through analytical modelling, detailed analysis is implemented to uncover the influence of positions on compliance characteristics. Finally, some desired designs are presented.

International audience; This paper presents the control of air supply of a Proton Exchange Membrane Fuel Cell-PEMFC-system. This control is based on a species balance model in the cathode (oxygen) compartment which must be controlled to stay not only at a constant pressure but also to follow a desired air flow. Desired air flow combined with sufficient hydrogen flow allows producing a maximal desired current for electrical load. In the context of a transport application (Tramway in this paper) pressure is increased from atmosphere to 1.5bar absolute, with a controlled compressor. The Moto-compressor group is based on a screw type compressor driven with a Permanent Magnet Synchronous Machine fed with a Pulse Width Modulation inverter. The non linear drive control structure is described and the compressor characteristics is used to have an accurate control of the air loop supply allowing to let the Fuel Cell in their own settings and to furnish power following the desired power profile.

Tutkimuksessa kehitettiin kokeellisesti varmennettuja suunnittelumenetelmiä valituille austeniittisesta ruostumattomasta teräksestä valmistetuille R30- ja R60-paloluokan puurakenteiden liitoksille. Lähtökohtana olivat kilpailukykyiset tappivaarna-, pultti-, vinotanko- ja palkkikenkäliitokset sekä uudentyyppiset holkkiliitokset. Tutkimuksessa tehtiin ruostumattomasta teräksestä valmistettujen palkkikenkä-, vinotanko-, tappivaarna- ja holkkiliitosten kuormituskokeita standardipalorasituksella ja normaalilämpötilassa. Palonkestävyyskokeiden yhteydessä tehtiin myös pienempiä kokeita tappivaarnojen lämpenemisen sekä ruuvien ja naulojen tartunnan selvittämiseksi korkeissa lämpötiloissa. Tutkimukseen kuului myös puikkoliitosten palonkestävyyttä koskeva kirjallisuusselvitys sekä liitosten lämpötilakentän laskennallisia mallinnuksia 30 min ja 60 min palorasituksella. Normaalilämpötilan kokeet osoittivat, että austeniittisista ruostumattomista teräksistä valmistettujen puurakenteiden liitosten mitoituksessa voidaan soveltaa Eurocode 5:tä. Liitosten paloteknisessä suunnittelussa tulee huomioida rst-materiaalin lujuuden ja kimmokertoimen alenemisen lisäksi myös mahdollinen liitoksen toimintatavan muuttuminen palotilanteessa sekä puun hiiltymisestä aiheutuva väljyys liitoksessa. Merkittävä puurakenteiden liitosten palonkestävyyden paraneminen voidaan saavuttaa hyödyntämällä ruostumattomien teräslaatujen hyviä lujuus- ja jäykkyysominaisuuksia korkeissa lämpötiloissa. Ruostumattomasta teräksestä valmistetuissa liitoksissa mitoittavaksi tekijäksi tulee yleensä puun hiiltyminen, joka on rst-levyn alla tai jopa suljetun rst-holkin sisällä yhtä nopeaa kuin suojaamattoman puupinnan hiiltyminen. Suojaamattomilla ulkopuolisilla rst-levyllisillä liitoksilla, kuten muotolevykiinnikkeillä ja holkkiliitoksilla, päästään ilman normaalilämpötilan ylimitoitusta R30-luokan palonkestävyyteen, kun liittimet ovat yli 60 mm pitkiä ja niiden reunaetäisyydet ovat riittävän suuria. Monileikkeisellä tappivaarnaliitoksella saavutetaan 60 min palonkestävyys ilman tappivaarnojen päiden suojausta ja ilman normaalilämpötilan ylimitoitusta, kun tappivaarnat ja puun sisään sijoitetut teräslevyt valmistetaan ruostumattomasta teräksestä. Tutkimustuloksiin perustuvat rst-liitosten rakennesuunnitteluohjeet on esitetty erillisessä VTT Working Papers 38 -julkaisussa.

In this paper, a novel design approach for the development of robot hands is presented. This approach can be considered alternative to the "classical" one for several reasons. First, the overall project addresses, besides the widespread specifications of dexterity and anthropomorphism, issues that some time are neglected or not fully considered in the design of robotic end-effectors, e.g. the structural complexity of the system, its reliability and costs. In order to achieve these results the tools used are also different from the traditional ones: compliant structures (e.g. elastic hinges) have been preferred to more standard robotic technologies, like pin bearing joints. Last, to cope with the problems due to the adopted mechanical technology (for instance undesired compliance effects) a mechatronic approach has been followed, which takes into account the all the possible interactions between mechanics, electronics and above all control. In the paper, this research activity is presented and the preliminary experimental tests on a first prototype are reported and discussed.

The excitation and vibration triggered by the long-term operation of railway vehicles inevitably result in defective states of catenary support devices. With the massive construction of high-speed electrified railways, automatic defect detection of diverse and plentiful fasteners on the catenary support device is of great significance for operation safety and cost reduction. Nowadays, the catenary support devices are periodically captured by the cameras mounted on the inspection vehicles during the night, but the inspection still mostly relies on human visual interpretation. To reduce the human involvement, this paper proposes a novel vision-based method that applies the deep convolutional neural networks (DCNNs) in the defect detection of the fasteners. Our system cascades three DCNN-based detection stages in a coarse-to-fine manner, including two detectors to sequentially localize the cantilever joints and their fasteners and a classifier to diagnose the fasteners' defects. Extensive experiments and comparisons of the defect detection of catenary support devices along the Wuhan-Guangzhou high-speed railway line indicate that the system can achieve a high detection rate with good adaptation and robustness in complex environments.

In the last decades, fastening systems have become an essential part of the construction industry. Post-installed mechanical anchors are frequently used in concrete members to connect them with other load bearing structural members, or to attach appliances. Their performance is limited by the concrete related failure modes which are highly influenced by the concrete mix design. This paper aims at investigating the effect that different aggregates used in the concrete mix have on the capacity of an undercut anchor under tensile quasi-static loading. Three concrete batches were cast utilising three different aggregate types. For two concrete ages (28 and 70 days), anchor tensile capacity and concrete properties were obtained. Concrete compressive strength, fracture energy and elastic modulus are used to normalize and compare the undercut anchor concrete tensile capacity employing some of the most widely used prediction models. For a more insightful comparison, a statistical method that yields also scatter information is introduced. Finally, the height and shape of the concrete cones are compared by highly precise and objective photogrammetric means.

OpenMP is the de facto standard application programming interface (API) for on-node parallelism. The most popular OpenMP runtimes rely on POSIX threads (pthreads) implementations that offer an excellent performance for coarse-grained parallelism and match perfectly with the current hardware. However, a recent trend in runtimes/applications points in the direction of leveraging massive on-node parallelism in conjunction with fine-grained and dynamic scheduling paradigms. It has been demonstrated that lightweight thread (LWT) solutions are more appropriate for these new parallel paradigms. We have developed GLTO, an OpenMP implementation over the recently-emerged Generic Lightweight Threads (GLT) API. GLT exports a common API for LWT libraries that offers the possibility of running the same application over different native LWT solutions. In this paper we use GLTO to analyze different scenarios where OpenMP implementations may benefit from the use of either LWT or pthreads. Our study reveals that none of the threading approaches obtains the best performance in all the scenarios, but that there are important gaps among them. The Researchers from the Universitat Jaume I de Castelló were supported by project TIN2014-53495-R of the MINECO and FEDER, the Generalitat Valenciana fellowship programme Vali+d 2015. Antonio J. Peña is cofinancied by the Spanish Ministry of Economy and Competitiveness under Juan de la Cierva fellowship number IJCI-2015-23266. This work was partially supported by the U.S. Dept. of Energy, Office of Science, Office of Advanced Scientific Computing Research (SC-21), under contract DE-AC02-06CH11357. We gratefully acknowledge the computing resources provided and operated by the Joint Laboratory for System Evaluation (JLSE) at Argonne National Laboratory.

Near to its official publication, Eurocode 2 part 4 (EN 1992-4) does not account for design of anchor plates under seismic action. Anchor plates, with cast in place fasteners, are commonly used in nuclear power plants to connect equipment to reinforced concrete structures. Such solutions provide a flat surface where the support of equipment may be welded, furthermore cast in place fasteners require no drilling holes thus avoiding additional sealing operations. Classic anchor plates typically use at least four fasteners, thus complicating the installation when high density of reinforcement is expected. New specific solutions with only one headed anchor are investigated in this paper: a more classic solution made with a single stud welded in the centre of the steel plate, and a more innovative one made with a piece of an IPE profile, welded in the centre of the steel plate. An experimental campaign was carried out by adapting existing European protocols for the assessment of post-installed anchors under seismic action. Static tests, pulsating tension load tests and tests with constant tension load and varying crack width were carried out in unconfined condition and in cracked concrete under different load conditions. Capacity reduction after cyclic tests is evaluated and compared with Concrete Capacity Design method (CCD) to prove its applicability as design method to these innovative solutions.

International audience; L-stubs are commonly used to model the tensile parts of ring flange bolted connections. Contact between opposite flanges has a significant effect on the elastic and plastic behaviour of these tensile joints. In the present paper, the effects of contact between flange plates are modelled via a refined beam model which has been previously applied with success to represent the elastic behaviour of non-preloaded L-stubs and T-stubs. Taking into account the behaviour of the flange in the contact area and bolt bending, a model is developed to predict the plastic resistance of L-stub joints. Simplifications are proposed to facilitate the determination of the contact zone and the ultimate resistances corresponding to failure modes involving flange and bolt. The comparison between analytical results with 3D finite element elasto-plastic analyses and experimental tests indicates that the proposed model provides good capacity predictions. Effects of contact, and therefore of the prying force, are particularly important in the case of relatively thin flanges. © 2017

There is an ongoing shift in industries from mass production to low-batch-production with highly individualized goods. This increases the programming effort required for the producing machines and robots, which is currently carried out by robot experts. For keeping the production economical, new programming approaches are required, allowing shop-floor workers to instruct robots. One approach is to develop robotic skills, which are pre-programmed software modules that only need to be parametrized by the shop-floor user. In this paper, a new software architecture for robot skills is presented, which aims at robustness and human-robot interaction. In addition, four basic demands on the skill parametrization are described that fasten up the process and increase intuitiveness for the user. We give several examples and implement a screwing skill and a pick & place skill, which are demonstrated in two case studies.

International audience; The condition based maintenance is an increasing challenge for flight control systems. In this paper, a methodology for the diagnosis of a roller screw in an electromechanical actuator is proposed. As this component is critical, its diagnosis is essential to use it on aircrafts. The methodology is based on the extraction of features by identifying a model of the actuator. First, a specific waveform, made of increasing steps of speed, is run on the actuator. Then, the measurements are processed to reduce the noise and the bias of the different sensors. In order to accelerate the identification, an equivalent point is calculated for each step of the waveform. Then, the identification is realized and the identified parameters are gathered in a feature vector. Finally, a model including backlash and deformation of the stem is used to validate the approach and to generate a set of data. The aging is simulated by making assumptions on the evolution of parameters. Classification is made by using k-Nearest Neighbors (kNN). Performances of the algorithm on this application are evaluated in terms of precision and robustness.

Fog computing is rapidly changing the distributed computing landscape by extending the Cloud computing paradigm to include wide-spread resources located at the network edges. This diffused infrastructure is well suited for the implementation of data stream processing (DSP) applications, by possibly exploiting local computing resources. Storm is an open source, scalable, and fault-tolerant DSP system designed for locally distributed clusters. We made it suitable to operate in a geographically distributed and highly variable environment; to this end, we extended Storm with new components that allow to execute a distributed QoS-aware scheduler and give self-adaptation capabilities to the system. In this paper we provide a thorough experimental evaluation of the proposed solution using two sets of DSP applications: the former is characterized by a simple topology with different requirements; the latter comprises some well known applications (i.e., Word Count, Log Processing). The results show that the distributed QoS-aware scheduler outperforms the centralized default one, improving the application performance and enhancing the system with runtime adaptation capabilities. However, complex topologies involving many operators may cause some instability that can decrease the DSP application availability.

In recent years important research activity has been undertaken in order to determine the earthquake performance of light gauge steel house structures. Usually, studies approach the problem of earthquake performance through experiments on wall panels conducted either under monotonic or cyclic loads. All studies underline the overwhelming importance that the behavior of the connections has in determining the overall performance of wall panels. However, although these studies focused on the global behavior of the panel, they did not try to characterize the behavior of and provide design criteria for connections, as components of the structural system, and to provide relevant design criteria. The present paper attempts to fill this gap.

International audience; Faced with an increasingly fast-changing market, airplane manufacturers have to reduce the development time of their new programs whilst dealing with more and more complex composite structures. The European project Maaximus (More Affordable Aircraft Structure Lifecycle through eXtended, Integrated & Mature nUmerical Sizing) aims at providing methods and tools to enable the fast development and right-first-time validation of a highly optimized composite airframe. In this context, accurate models of fasteners are crucial to ensure correct structure modeling at a higher level. The present study focuses on the mechanical behavior of a threaded assembly subjected to an axial tensile load. After a review of the state-of-the-art in this domain, the first part of the paper shows what benefits can be expected from explicit simulation for large quasistatic models. Parallelization strategies for High-Performance Computing (HPC) are presented, bringing out the need for consistency between the parallelization strategy and the computation structure. These simulation techniques are then applied to the modeling of a tensile test of a fastener. The results of corresponding experiments for two fastener diameters are presented. A successful correlation between simulations and experiments is found, both qualitatively and quantitatively. This study shows the efficiency of a well-chosen resolution algorithm in a coherent HPC environment for solving large non-linear models.

INSPEC Accession Number: 10364160; International audience; This paper presents ABLE, an innovative exoskeleton for the upper limb currently under development at CEA-LIST Interactive Robotics Unit (Fig 1). Its distinctive high performance mechanical transmissions-screw and cable patented arrangement [9]-and its integrated architecture makes it the very first of its category. The first 4 axis model is described here but more complete models are already planned: a 7 axis model as well as portable versions. Its back-drivable, high efficiency, low inertia actuators provide a high capacity (around 40 N continuous effort at the hand) and allow hybrid force-position control without requiring any force sensor. Its first application is currently a research program in rehabilitation (BRAHMA project) and professional use is already in view. Assistance tasks for disabled persons (carrying a bottle) are also typical tasks to be performed by ABLE as well as intuitive telerobotics, haptic device for VR, and sport training, etc. Furthermore, its versatility and simple design allow industrial versions to become soon available. Fig 1. CEA-LIST 4 axis exoskeleton actuated by screw-and-cable actuators (SCS actuator) I. THE GENESIS OF ABLE-A SHORT STORY OF THE SCS ACTUATOR ABLE exoskeleton is directly related to electrical master-slave manipulator (EMSM) teleoperation technology in which our laboratory has played a historical role. Fig 2 shows a quick summary of well-known pioneering machines [8], [11], [12], [13], [14], [15], [16] illustrated with their mechanical solutions. Model E1Î circa 1954 (ANL/CRL) Joint transmission cable Motors (multiples) Spur gears Model E1Î circa 1954 (ANL/CRL) Joint transmission cable Motors (multiples) Spur gears Joint transmission cable Motors (multiples) Spur gears MA 23 circa 1974 (CEA/La Calhène) Motor Cabstan (positive) Block-and-tackle Joint transmission cable MA 23 circa 1974 (CEA/La Calhène) Motor Cabstan (positive) Block-and-tackle Joint transmission cable Motor Cabstan (positive) Block-and-tackle Joint transmission cable Hand Controller circa 1990 (JPL) Capstan (adherence) e Joint transmission cable Hand Controller circa 1990 (JPL) Capstan (adherence) e Joint transmission cable Capstan (adherence) Capstan (adherence) e e Joint transmission cable Fig 2. Landmarks in torque amplification for back-drivable electrical master-slave telemanipulator (EMSM) The first principle has been used by R. Goertz (ANL) in his E1-E4 and Model M. Motor torque is amplified using high-precision spur gears driving the joints either directly (translation joints) or, like the scheme shows, trough transmission cable (for remote rotation joints). The second is due to J. Vertut and is team (CEA) for the MA 23. Motor

Tutkimuksessa kehitettiin kokeellisesti varmennettuja suunnittelumenetelmiä valituille austeniittisesta ruostumattomasta teräksestä valmistetuille R30- ja R60-paloluokan puurakenteiden liitoksille. Lähtökohtana olivat kilpailukykyiset tappivaarna-, pultti-, vinotanko- ja palkkikenkäliitokset sekä uudentyyppiset holkkiliitokset. Tutkimuksessa tehtiin ruostumattomasta teräksestä valmistettujen palkkikenkä-, vinotanko-, tappivaarna- ja holkkiliitosten kuormituskokeita standardipalorasituksella ja normaalilämpötilassa. Palonkestävyyskokeiden yhteydessä tehtiin myös pienempiä kokeita tappivaarnojen lämpenemisen sekä ruuvien ja naulojen tartunnan selvittämiseksi korkeissa lämpötiloissa. Tutkimukseen kuului myös puikkoliitosten palonkestävyyttä koskeva kirjallisuusselvitys sekä liitosten lämpötilakentän laskennallisia mallinnuksia 30 min ja 60 min palorasituksella. Normaalilämpötilan kokeet osoittivat, että austeniittisista ruostumattomista teräksistä valmistettujen puurakenteiden liitosten mitoituksessa voidaan soveltaa Eurocode 5:tä. Liitosten paloteknisessä suunnittelussa tulee huomioida rst-materiaalin lujuuden ja kimmokertoimen alenemisen lisäksi myös mahdollinen liitoksen toimintatavan muuttuminen palotilanteessa sekä puun hiiltymisestä aiheutuva väljyys liitoksessa. Merkittävä puurakenteiden liitosten palonkestävyyden paraneminen voidaan saavuttaa hyödyntämällä ruostumattomien teräslaatujen hyviä lujuus- ja jäykkyysominaisuuksia korkeissa lämpötiloissa. Ruostumattomasta teräksestä valmistetuissa liitoksissa mitoittavaksi tekijäksi tulee yleensä puun hiiltyminen, joka on rst-levyn alla tai jopa suljetun rst-holkin sisällä yhtä nopeaa kuin suojaamattoman puupinnan hiiltyminen. Suojaamattomilla ulkopuolisilla rst-levyllisillä liitoksilla, kuten muotolevykiinnikkeillä ja holkkiliitoksilla, päästään ilman normaalilämpötilan ylimitoitusta R30-luokan palonkestävyyteen, kun liittimet ovat yli 60 mm pitkiä ja niiden reunaetäisyydet ovat riittävän suuria. Monileikkeisellä tappivaarnaliitoksella saavutetaan 60 min palonkestävyys ilman tappivaarnojen päiden suojausta ja ilman normaalilämpötilan ylimitoitusta, kun tappivaarnat ja puun sisään sijoitetut teräslevyt valmistetaan ruostumattomasta teräksestä. Tutkimustuloksiin perustuvat rst-liitosten rakennesuunnitteluohjeet on esitetty erillisessä VTT Working Papers 38 -julkaisussa.

Fixing hardware made of carbon, high-carbon, and alloyed wires is one of the widespread critical parts in mechanical engineering. The characteristics of fixtures and fasteners and their performance figures are assessed at all stages of steel-making operation, from the choice of burden stock for metal smelting to the method of preparing calibrated rolled metal parts and upsetting end products. Material used for producing long high-duty bolts must be both sufficiently strong and ductile, have homogeneous mechanical properties and chemistry, and no inner or surface defects. When manufacturing fasteners, hot-rolled metal is often plastically deformed by drafting before cold upsetting, and all unacceptable defects are removed by the expensive procedure of lathe-turning. Moreover, this technology of metal processing entails losses of up to 5.5 % in chips. This paper suggests a resource-efficient and environmentally friendlier fabrication method for calibrated rolled metal items made of steel 38XA, 9.65 mm diameter, for cold die-forging of high-duty bolts used in automotive engines, which helps spare expensive lathe-machining processes. Moreover, rolled steel produced using this technology is characterized by high resistance to plastic deformation when cold, which leads to increase n wear-resistance of tools in cold die-forging of bolts.