On the Performance of Welded, Riveted and Adhesive Bonded Al/Mg Sheet Metal Joints

2011 ◽  
Vol 473 ◽  
pp. 237-242 ◽  
Author(s):  
Marco Alfano ◽  
Giuseppina Ambrogio ◽  
Luigino Filice ◽  
Franco Furgiuele ◽  
Enrico Gallus ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Adhesive Bonding ◽  
State Of The Art ◽  
Mg Alloys ◽  
The Other ◽  
Fuel Saving ◽  
Mig Welding ◽  
Technical Problems ◽  
Hybrid Joints ◽  
Joining Process

Aluminum (Al) and Magnesium (Mg) alloys are nowadays widely employed in order to produce lightweight automotive and aeronautical components and to gain fuel saving and reduced emissions. However, the joining of Al and Mg alloys poses well known technical problems and the application of conventional joining techniques, e.g. welding, may be ineffective. On the other hand, adhesive bonding may be considered as a candidate replacement of the traditional techniques and for this reason it has been recently proposed as an alternative technology for Al/Mg joints. In particular, it has been demonstrated that adhesive bonding, in conjunction with state-of-the-art surface treatments, can provide Al/Mg joint with enhanced strength. However, in order to evaluate the potential of adhesive bonding to outperform the conventional joining techniques a systematic comparative analysis is needed. Therefore, the aim of this work is to supplement the existing studies on Al/Mg bonding providing a comparative analysis between Al/Mg joints prepared using gas metal arc (MIG) welding, riveting and adhesive bonding. Probably, the use of adhesive bonding as complementary joining process will be the industrial answer to the hybrid joints performance needs.

Adhesive Distribution and Global Deformation between Hybrid Joints

2015 ◽  
Vol 651-653 ◽  
pp. 1465-1471 ◽  
Author(s):  
Dirk Landgrebe ◽  
Bernd Mayer ◽  
Stephan Niese ◽  
Holger Fricke ◽  
Ivo Neumann ◽  
...  
Keyword(s):  
Automotive Industry ◽  
High Speed ◽  
Adhesive Bonding ◽  
Measurement Technology ◽  
Detailed Knowledge ◽  
Small Surface ◽  
Mechanical Joining ◽  
Hybrid Joint ◽  
Hybrid Joints ◽  
Joining Process

In multi-material-design, e.g. in the automotive industry, mechanical joining processes like self-pierce riveting are well established, because of their amount of advantages. However, adhesive bonding with one-component structural adhesives is increasingly being used. The combination of the specific advantages of both joining techniques in the form of hybrid joints leads to synergies of quality and reliability, such as high corrosion resistance and better damping properties. A critical issue is the generation of global deformations of the different parts of the mechanical joints. These global deformations of the sheet metal between two or more mechanical connectors (e.g. rivets) are caused by the formation of adhesive bags during the riveting process, before the adhesive curing takes place. This research focuses on the time-dependent formation process of these bags. The aim is to achieve a reduction of global deformations based on detailed knowledge of the adhesive flow during the manufacturing of the joint by means of experiments and simulations. For this purpose experimental techniques and measurement methods for deformations over time are presented for different setups of hybrid joint types of self-piercing rivets in combination with adhesive bonding. The challenge is to track rapid and small surface deformations very accurately in the ongoing mechanical joining process. High-speed optical measurement technology like Point-Tracking and surface scanning are used to track the resulting deformations experimentally. Numerical investigations, which include the interaction of the solid matter influenced in the mechanical joining process and the fluid adhesive, are presented. On the basis a fully coupled fluid-structure interaction simulation of a single hybrid joint, a surrogate model for a multi-point hybrid joint is developed. The comparison of experimental data with simulations allows deriving the pressure distribution and flow velocities inside the adhesive layer. The influence of various parameters can be interpreted based on the physics of the interacting system, ultimately resulting in optimization helpful to the automotive industry.

Case‐Oriented Configura‐Tional Research: Qualitative Comparative Analysis (Qca), Fuzzy Sets, and Related Techniques

2009 ◽  
Author(s):  
Benoît Rihoux
Keyword(s):  
Comparative Analysis ◽  
Best Practices ◽  
Fuzzy Sets ◽  
State Of The Art ◽  
Qualitative Comparative Analysis ◽  
Short Description ◽  
The Other ◽  
Technical Advances ◽  
The One ◽  
Cross Fertilization

This article investigates the tradition of case-oriented configurational research, focusing specifically on qualitative comparative analysis (QCA) as a tool for causal inference. It first presents two analytic procedures commonly used by comparative researchers. A short description of the state-of-the-art of QCA applications is offered, in terms of discipline, types of cases, models, combinations with other methods, and software development. It then reviews different uses of QCA, as well as generic ‘best practices’. Some key recent evolutions are illustrated: on the one hand the development, beyond dichotomous ‘crisp set’ QCA (csQCA), of multi-value QCA (mvQCA), fuzzy sets, and fuzzy-set QCA (fsQCA), and on the other hand technical advances and refinements in the use of the techniques. Finally, the article gives some concluding reflections as to expected developments, upcoming innovations, remaining challenges, expansion of fields of application, and cross-fertilization with other approaches.

Computer Vision and robotics in postal automation

1999 ◽  
Vol 18 (3-4) ◽  
pp. 265-273
Author(s):  
Giovanni B. Garibotto
Keyword(s):  
Image Processing ◽  
Computer Vision ◽  
Pattern Recognition ◽  
Material Handling ◽  
State Of The Art ◽  
Short Description ◽  
The Other ◽  
Functional Requirements ◽  
Postal Automation ◽  
And Robotics

The paper is intended to provide an overview of advanced robotic technologies within the context of Postal Automation services. The main functional requirements of the application are briefly referred, as well as the state of the art and new emerging solutions. Image Processing and Pattern Recognition have always played a fundamental role in Address Interpretation and Mail sorting and the new challenging objective is now off-line handwritten cursive recognition, in order to be able to handle all kind of addresses in a uniform way. On the other hand, advanced electromechanical and robotic solutions are extremely important to solve the problems of mail storage, transportation and distribution, as well as for material handling and logistics. Finally a short description of new services of Postal Automation is referred, by considering new emerging services of hybrid mail and paper to electronic conversion.

Occupant pre-crash kinematics in rotated seat arrangements

2021 ◽  
pp. 095440702110045
Author(s):  
Alexander Diederich ◽  
Christophe Bastien ◽  
Karthikeyan Ekambaram ◽  
Alexis Wilson
Keyword(s):  
State Of The Art ◽  
The Other ◽  
Human Model ◽  
Multi Objective ◽  
Emergency Braking ◽  
Seating Arrangement ◽  
Current State ◽  
Occupant Comfort ◽  
Occupant Kinematics ◽  
Belt System

The introduction of automated L5 driving technologies will revolutionise the design of vehicle interiors and seating configurations, improving occupant comfort and experience. It is foreseen that pre-crash emergency braking and swerving manoeuvres will affect occupant posture, which could lead to an interaction with a deploying airbag. This research addresses the urgent safety need of defining the occupant’s kinematics envelope during that pre-crash phase, considering rotated seat arrangements and different seatbelt configurations. The research used two different sets of volunteer tests experiencing L5 vehicle manoeuvres, based in the first instance on 22 50th percentile fit males wearing a lap-belt (OM4IS), while the other dataset is based on 87 volunteers with a BMI range of 19 to 67 kg/m2 wearing a 3-point belt (UMTRI). Unique biomechanics kinematics corridors were then defined, as a function of belt configuration and vehicle manoeuvre, to calibrate an Active Human Model (AHM) using a multi-objective optimisation coupled with a Correlation and Analysis (CORA) rating. The research improved the AHM omnidirectional kinematics response over current state of the art in a generic lap-belted environment. The AHM was then tested in a rotated seating arrangement under extreme braking, highlighting that maximum lateral and frontal motions are comparable, independent of the belt system, while the asymmetry of the 3-point belt increased the occupant’s motion towards the seatbelt buckle. It was observed that the frontal occupant kinematics decrease by 200 mm compared to a lap-belted configuration. This improved omnidirectional AHM is the first step towards designing safer future L5 vehicle interiors.

scholarly journals All-gather Algorithms Resilient to Imbalanced Process Arrival Patterns

2021 ◽  
Vol 18 (4) ◽  
pp. 1-22
Author(s):  
Jerzy Proficz
Keyword(s):  
Experimental Evaluation ◽  
Data Exchange ◽  
State Of The Art ◽  
Monitoring And Evaluation ◽  
The Other ◽  
Early Data ◽  
Cluster Architecture ◽  
Novel Algorithms

Two novel algorithms for the all-gather operation resilient to imbalanced process arrival patterns (PATs) are presented. The first one, Background Disseminated Ring (BDR), is based on the regular parallel ring algorithm often supplied in MPI implementations and exploits an auxiliary background thread for early data exchange from faster processes to accelerate the performed all-gather operation. The other algorithm, Background Sorted Linear synchronized tree with Broadcast (BSLB), is built upon the already existing PAP-aware gather algorithm, that is, Background Sorted Linear Synchronized tree (BSLS), followed by a regular broadcast distributing gathered data to all participating processes. The background of the imbalanced PAP subject is described, along with the PAP monitoring and evaluation topics. An experimental evaluation of the algorithms based on a proposed mini-benchmark is presented. The mini-benchmark was performed over 2,000 times in a typical HPC cluster architecture with homogeneous compute nodes. The obtained results are analyzed according to different PATs, data sizes, and process numbers, showing that the proposed optimization works well for various configurations, is scalable, and can significantly reduce the all-gather elapsed times, in our case, up to factor 1.9 or 47% in comparison with the best state-of-the-art solution.

scholarly journals Development of Multiple Behaviors in Evolving Robots

Robotics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Victor Massagué Respall ◽  
Stefano Nolfi
Keyword(s):  
Evolutionary Algorithms ◽  
State Of The Art ◽  
Evolutionary Robotics ◽  
The Other ◽  
Evolutionary Strategies ◽  
Multiple Behaviors ◽  
Pareto Fronts ◽  
Expected Fitness

We investigate whether standard evolutionary robotics methods can be extended to support the evolution of multiple behaviors by forcing the retention of variations that are adaptive with respect to all required behaviors. This is realized by selecting the individuals located in the first Pareto fronts of the multidimensional fitness space in the case of a standard evolutionary algorithms and by computing and using multiple gradients of the expected fitness in the case of a modern evolutionary strategies that move the population in the direction of the gradient of the fitness. The results collected on two extended versions of state-of-the-art benchmarking problems indicate that the latter method permits to evolve robots capable of producing the required multiple behaviors in the majority of the replications and produces significantly better results than all the other methods considered.

scholarly journals Density Guarantee on Finding Multiple Subgraphs and Subtensors

2021 ◽  
Vol 15 (5) ◽  
pp. 1-32
Author(s):  
Quang-huy Duong ◽  
Heri Ramampiaro ◽  
Kjetil Nørvåg ◽  
Thu-lan Dam
Keyword(s):  
Lower Bound ◽  
State Of The Art ◽  
The State ◽  
The Other ◽  
Exact Methods ◽  
Practical Solution ◽  
Novel Approach ◽  
Wide Range ◽  
Real World Datasets ◽  
Tensor Data

Dense subregion (subgraph & subtensor) detection is a well-studied area, with a wide range of applications, and numerous efficient approaches and algorithms have been proposed. Approximation approaches are commonly used for detecting dense subregions due to the complexity of the exact methods. Existing algorithms are generally efficient for dense subtensor and subgraph detection, and can perform well in many applications. However, most of the existing works utilize the state-or-the-art greedy 2-approximation algorithm to capably provide solutions with a loose theoretical density guarantee. The main drawback of most of these algorithms is that they can estimate only one subtensor, or subgraph, at a time, with a low guarantee on its density. While some methods can, on the other hand, estimate multiple subtensors, they can give a guarantee on the density with respect to the input tensor for the first estimated subsensor only. We address these drawbacks by providing both theoretical and practical solution for estimating multiple dense subtensors in tensor data and giving a higher lower bound of the density. In particular, we guarantee and prove a higher bound of the lower-bound density of the estimated subgraph and subtensors. We also propose a novel approach to show that there are multiple dense subtensors with a guarantee on its density that is greater than the lower bound used in the state-of-the-art algorithms. We evaluate our approach with extensive experiments on several real-world datasets, which demonstrates its efficiency and feasibility.

scholarly journals Fast Accurate and Automatic Brushstroke Extraction

2021 ◽  
Vol 17 (2) ◽  
pp. 1-24
Author(s):  
Yunfei Fu ◽  
Hongchuan Yu ◽  
Chih-Kuo Yeh ◽  
Tong-Yee Lee ◽  
Jian J. Zhang
Keyword(s):  
Neural Network ◽  
Efficient Algorithm ◽  
Deep Neural Network ◽  
High Efficiency ◽  
State Of The Art ◽  
High Reliability ◽  
The Other ◽  
Manual Annotation ◽  
Stroke Extraction ◽  
Art Research

Brushstrokes are viewed as the artist’s “handwriting” in a painting. In many applications such as style learning and transfer, mimicking painting, and painting authentication, it is highly desired to quantitatively and accurately identify brushstroke characteristics from old masters’ pieces using computer programs. However, due to the nature of hundreds or thousands of intermingling brushstrokes in the painting, it still remains challenging. This article proposes an efficient algorithm for brush Stroke extraction based on a Deep neural network, i.e., DStroke. Compared to the state-of-the-art research, the main merit of the proposed DStroke is to automatically and rapidly extract brushstrokes from a painting without manual annotation, while accurately approximating the real brushstrokes with high reliability. Herein, recovering the faithful soft transitions between brushstrokes is often ignored by the other methods. In fact, the details of brushstrokes in a master piece of painting (e.g., shapes, colors, texture, overlaps) are highly desired by artists since they hold promise to enhance and extend the artists’ powers, just like microscopes extend biologists’ powers. To demonstrate the high efficiency of the proposed DStroke, we perform it on a set of real scans of paintings and a set of synthetic paintings, respectively. Experiments show that the proposed DStroke is noticeably faster and more accurate at identifying and extracting brushstrokes, outperforming the other methods.

scholarly journals Representing the victorious past: Chinese revolutionary TV drama between propaganda and marketization

2021 ◽  
pp. 016344372110227
Author(s):  
Yingzi Wang ◽  
Thoralf Klein
Keyword(s):  
Comparative Analysis ◽  
The Other ◽  
Market Reforms ◽  
Fictional Characters ◽  
Production Environment ◽  
Cultural Transformations ◽  
The One ◽  
Political Economic ◽  
Revolutionary History ◽  
Over Time

This paper examines the changes and continuities in TV representations of Chinese Communist Party’s revolutionary history and interprets them within the broader context of China’s political, economic and cultural transformations since the 1990s. Drawing on a comparative analysis of three state-sponsored TV dramas produced between the late 1990s and mid-2010s, it traces how the state-sanctioned revolutionary narratives have changed over time in response to the Party’s propaganda imperatives on the one hand, and to the market-oriented production environment on the other. The paper argues that while recent TV productions in the new century have made increasing concessions to audience taste by adopting visually stimulating depictions and introducing fictional characters as points of identification for the audience, the revolutionary narratives were still aligned with the Party’s propaganda agenda at different times. This shows the ongoing competition between ideological and commercial interests in Chinese TV production during the era of market reforms.

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