A solving tool for fuzzy quadratic optimal control problems

In this paper we propose an iterative method to solve an optimal control problem, with fuzzy target and constraints. The algorithm is developed in such a way as to satisfy the target function and the constraints. The algorithm can be applied only if a method exists to solve a crisp parametric sub-problem obtained by the original one. This is the case for a quadratic-linear target function with linear constraints, for which some well established solvable methods exist for the crisp associated sub-problem. A numerical test confirmed the good convergence properties.fuzzy, mathematical programming

Study of an intrinsically safe infrastructure for training and research on nuclear technologies

Within European Partitioning & Transmutation research programs, infrastructures specifically dedicated to the study of fundamental reactor physics and engineering parameters of future fast-neutron-based reactors are very important, being some of these features not available in present zero-power prototypes. This presentation will illustrate the conceptual design of an Accelerator-Driven System with high safety standards, but ample flexibility for measurements. The design assumes as base option a 70MeV, 0.75mA proton cyclotron, as the one which will be installed at the INFN National Laboratory in Legnaro, Italy and a Beryllium target, with Helium gas as core coolant. Safety is guaranteed by limiting the thermal power to 200 kW, with a neutron multiplication coefficient around 0.94, loading the core with fuel containing Uranium enriched at 20% inserted in a solid-lead diffuser. The small decay heat can be passively removed by thermal radiation from the vessel. Such a system could be used to study, among others, some specific aspects of neutron diffusion in lead, beam-core coupling, target cooling and could serve as a training facility

Panzerwerke : Teoria, história e técnica dos fortes couraçados modernos na frente sudoeste da Áustria-Hungria. 1900-1915

Tese de doutoramento, Arquitetura (Teoria e História), Universidade de Lisboa, Faculdade de Arquitetura, 2022Os primeiros anos do século XX foram caraterizados per um período de paz e de relativo bem-estar. Mas atrás da cortina de normalidade, os governos e as hierarquias militares estavam experimentando novas tecnologias que, dali a uns anos, revelariam por inteiro a sua capacidade de extermínio e destruição. Em particular na Áustria-Hungria desenvolveu-se uma Teoria das Fortificações, sendo também cúmplices as novas capacidades tecnológicas no campo siderúrgico, que, em poucos anos, produziram uma série de fortes couraçados, filhos do debate teórico na Ciência das Fortificações que se estendeu entre o séc. XIX e o séc. XX e que de facto são descendentes das realizações no âmbito da fortificação permanente europeia. Esta investigação teórica e histórica pretendeu estudar a Ciência das Fortificações na Áustria, como também, em paralelo, a teorização e prática na Europa da época, observando depois quais foram as obras couraçadas projetadas e realizadas ao longo das fronteiras do Süd-Tirol italiano no Império Austro-Húngaro. O trabalho da tese baseou-se igualmente na pesquisa de arquivos em Itália e na Áustria, na observação direta dos fortes e também, em parte, na consulta da documentação original do Génio Militar e do Ministério da Guerra austríacos, dos textos originais da época, italianos e austríacos, sobre a fortificação permanente. Foi também consultada uma bibliografia apropriada. A tese aborda o tema das posições fortes em montanha segundo a teoria militar, destacando o momento da sua aplicação prática à fronteira sudtirolesa, descrevendo depois a linguagem específica da Ciência das Fortificações, e o desenvolvimento das obras couraçadas permanentes de montanha, vistos no contexto histórico, cultural e ambiental do tempo, compreendendo como estas foram consequência das realizações a nível europeu, o que evidencia a natureza e as dimensões do “fenómeno dos Fortes Couraçados” na fronteira Sul do Império, fazendo-o entrar de pleno direito na História da Arquitetura Moderna do início de ‘900.N/

BIM a scala urbana, ricerche, analisi e interazione tra dati per l’organismo Venezia

2noLa costruzione di un sistema informativo che includa anche modelli geometrici è un tema di lunga data, più volte trattato nella letteratura scientifica a partire dalla metà degli anni Ottanta ma ancora attuale. Il fine comune è rimasto quello dell’utilizzo della computazione per migliorare la gestione dell’ambiente costruito. La disponibilità di informazioni, geometriche e numeriche, legate ad una posizione geografica specifica, è di interesse tanto per ambiti tipicamente di pubblica utilità (gestione del territorio e degli edifici pubblici, infrastrutture, ecc.), quanto per settori industriali (telecomunicazioni, distribuzione di energia elettrica, gas e petrolio, agricoltura, progettazione paesaggistica, ecc.). La ricerca accademica in questo senso viene presentata sia da geografi, interessati a traslare le proprie tecniche in ambito digitale, sia da programmatori, per ipotizzare l’uso di database in ambito spaziale. Il contributo ipotizza l'impiego di metodologie Bim applicate alla città di Venezia, considerando tale luogo come un organismo vivente inserito nel suo sistema lagunare, al fine di migliorare la gestione della città e del territorio.openopenAlessio Bortot; Paolo BorinBortot, Alessio; Borin, Paol

The determination of flow stress of tubular material for hydrofoming applications

3Tube hydroforming (THF) process is nowadays a developed and successful way for forming of complex shapes with less operations required compared to conventional tube forming processes. FE simulations are powerful tools which allow a remarkable saving in time and money when developing a feasibility study or a prototype phase for a new THF operation. However the successful use of FE simulations depends on several factors such as interface friction or material properties. While in the past flow stress used as input in FE simulations was generally obtained from tensile test conducted on the sheet prior to rolling and welding operations in case of rolled and welded tubes, or tensile test conducted on the whole tube for extruded or seamless tubes, in the last years tube bulge test has been widely used. In this research test experiments, coupled with suitable analytical model of the process, are used to identify the flowstress of tubes (under biaxial stress state) by measuring geometrical features of the tube under study as the fluid pressure increases. In the present paper a new approach to tube bulge test is described. The innovative aspect is related to the fact that the tube ends are blocked and so the equilibrium expression in axial direction normally used to calculate stresses is no more valid. The stress state is therefore derived from the flow rule and the volume constancy. The new proposed analytical model was validated by means of FE simulations. Results of test conducted on seamless tubes show that bulge test allows to obtain material properties for high strain thus avoiding possible errors in extrapolating flow stress for FE simulations.reservedmixedP.BORTOT; E. CERETTI; C.GIARDINIBortot, Paolo; Ceretti, Elisabetta; Giardini, Claudi

The determination of flow stress of tubular material for hydroforming applications

Tube hydroforming (THF) process is nowadays a developed and successful way for forming of complex shapes with less operations required compared to conventional tube forming processes. FE simulations are powerful tools which allow a remarkable saving in time and money when developing a feasibility study or a prototype phase for a new THF operation. However the successful use of FE simulations depends on several factors such as interface friction or material properties. While in the past flow stress used as input in FE simulations was generally obtained from tensile test conducted on the sheet prior to rolling and welding operations in case of rolled and welded tubes, or tensile test conducted on the whole tube for extruded or seamless tubes, in the last years tube bulge test has been widely used. In this research test experiments, coupled with suitable analytical model of the process, are used to identify the flow stress of tubes (under biaxial stress state) by measuring geometrical features of the tube under study as the fluid pressure increases. In the present paper a new approach to tube bulge test is described. The innovative aspect is related to the fact that the tube ends are blocked and so the equilibrium expression in axial direction normally used to calculate stresses is no more valid. The stress state is therefore derived from the flow rule and the volume constancy. The new proposed analytical model was validated by means of FE simulations. Results of test conducted on seamless tubes show that bulge test allows to obtain material properties for high strain thus avoiding possible errors in extrapolating flow stress for FE simulations

Design of a feedback algorithm to control axial actuators movement in tube hydroforming process

Tube Hydroforming (THF) process is nowadays gaining more and more importance especially in automotive industry. Several companies developed dedicated equipments for the THF series production and THF is becoming a reference technology due to its advantages. This paper deals with the development and testing of a feedback algorithm to control axial actuators movement in a THF equipment. The algorithm and the whole THF device were designed and manufactured by the Technologies and Manufacturing Systems Research Group of University of Brescia and Bergamo with the cooperation of several companies, and it is currently working in the University of Brescia lab