Models Sequencing Optimization for an Automated Fully Flexible Assembly System (F-FAS)

Sequencing optimization is historically related to the case assembly lines.Is possible to consider a particular single station system where the models sequencing optimization is a critical problem:The Fully Flexible Assembly System (F-FAS) (Rosati et al., Assembly Automation Vol.1- 2, 2013),an answer in case of high flexibility/low volumes scenarios.The system relies on a fullyflexible feeder,responsible for the parts delivery for assembly. Since in the F-FAS the feeding process is stochastic in nature,the defined sequence of model to assembly is critical in the complete order execution time

Effects of corrosion on low-cycle fatigue (seismic) behaviour of high-strength steel reinforcing bars (Rusteel)

The dissipative capacity of modern r.c. and composite steel/concrete structures is directly related to the rotational capacity of the elements in which plastic hinges are located: it strictly depends on the geometrical and mechanical characteristics of the sections and, moreover, on the ductile capacity of the steel reinforcing bars (deformation and dissipated energy). Nowadays the lowcycle fatigue/seismic behaviour of steel reinforcing bars is not well known and, at European level, no production control tests are prescribed for the mechanical characterisation of the seismic performance of reinforcing steels. This situation is well reflected in the framework of the revision of European standard EN10080 and in Mandate M115 which tends to harmonise production control for reinforcing steels also introducing low-cycle fatigue tests. Full knowledge about the effective ductility requirements imposed on bars by real seismic events is necessary: a detailed analysis of the ductility demand on reinforcements, considering both r.c. and composite steel/concrete structures, is consequently necessary and deeply analysed in the project. At the same time, the ductility capacity of steel reinforcing bars has been investigated considering also the detrimental effects due to aggressive environmental conditions, generally resulting in a progressive decrease of the mechanical characteristics of deformation, strength and dissipative capacity. The evaluation of the ability of corroded steel bars to still sustain the ductile requirements due to seismic action has been analysed, finally providing practical indications for the protection of bars from corrosion, in addition to what was already suggested by Eurocode

Compared analysis of two different software for iron overload quantification in cardiac MRI

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Fatigue damage control and assessment for railways bridges (FADLESS)

The functionality maintenance of infrastructures like bridges is acquiring more and more importance due to the huge economic losses related to the interruption of their regular service. In particular, fatigue represents one of the more diffused failure modes occurring in steel and composite steel-concrete bridges: in fact, about 80 to 90 % of failures in steel structures are related to fracture and fatigue. Railway bridges endure millions of stress cycles during their life and they are expected to be highly vulnerable to such phenomena. The fatigue assessment of railway bridges; both considering the design of new bridges and the assessment of existing ones, is one of the main issues in current practice. In fact, phenomena like ‘vibration induced’ and ‘distortion induced’ fatigue are still not completely covered by current design codes and represent a critical aspect for the assessment of steel bridges. The objective of the project was the development of a modern procedure for the evaluation of the structural integrity of steel railway bridges which may be affected by fatigue damage under the application of a large number of load cycles during their lifetime. To this aim, an innovative methodology for advanced fatigue assessment was developed and calibrated on six suitable case studies which were representative of typical European steel solutions for railway bridges subjected to vibration/distortion phenomena. The application of the proposed methodology to case studies confirmed its capabilities in providing reliable and extensive information concerning the current fatigue damage and the remaining life of bridge component

Applications of Learning Algorithms to Industrial Robotics

Learning algorithms are becoming popular in industrial manufacturing thanks to their promise to make a robot conscious of its surroundings and capable of human-like abilities, gaining greater flexibility with respect to traditional robotic systems. The aim is to operate also complex tasks without the need for explicit instructions, permitting the creation of fully autonomous systems where human operators are not included. A panoramic of the current state of the art in industrial fields is presented, starting from object recognition and grasping pose detection, to task planning and applications based on demonstrations by the operator

Mixed-model sequencing optimization for an automated single-station fully flexible assembly system (F-FAS)

Flexible automated assembly is an emerging need in several industries. In the case of a very wide set of models and a total medium/low derived production volume, the proper assembly system to use is a single cell with high flexibility capabilities. An innovative concept in flexible automated assembly has recently been introduced: the fully flexible assembly system (F-FAS). The F-FAS relies on a single-station robotized assembly system, where a unique fully flexible feeder is responsible for the delivery of the parts needed for assembly, guaranteeing a higher level of flexibility than the traditional automated FAS. The mixed-model sequencing (MMS) problem is typically related to the assembly line system. The aim of this paper is to introduce a new class of MMS problem: the single-station mixed-model sequencing problem that arises when the parts to assemble are randomly presented on the working plane, as in the F-FAS. The authors first define theMMS in such a single-station assembly system and then propose different sequencing algorithms in order to solve it. The authors first define the problem and then propose different sequencing algorithms. With the aim of finding the best sequencing approach to use in such an assembly system, the algorithms are compared through ad hoc developed benchmarking tests, using a dedicated software application that simulates the real behavior of the work cell