Valeria Machiunas (mmachiu@FI.UBA.AR)
Sun, 13 Jun 1999 00:07:20 -0300
Message-ID: <3.0.1.16.19990612054320.282f1b40@tron.fi.uba.ar>
Date: Sun, 13 Jun 1999 00:07:20 -0300
From: Valeria Machiunas <mmachiu@FI.UBA.AR>
Subject: fractura : Damage and Fracture Mechanics in Concrete,
To: CIVIL-L@hermes.csd.unb.ca
Excuse me if you had received this:
>From: pipina@uncoma.edu.ar
>Date: Fri, 11 Jun 1999 18:15:56 -0300
>To: fractura@ccc.uba.ar
>Subject: fractura:Damage and Fracture Mechanics in Concrete, Rocks and
Ceramics
>
>>From: Clare Bridle <cbridle@wessex.ac.uk>
>>To: cbridle@wessex.ac.uk
>>Date: Wed, 9 Jun 1999 16:48:20 BST
>>Subject: Damage and Fracture Mechanics in Concrete, Rocks and Ceramics
>>
>>Dear Colleague
>>
>>I enclose details of a short course on Damage and Fracture Mechanics
>>in Concrete, Rocks and Ceramics which will be held at the Wessex
>>Institute of Technology from 30 June to 2 July 1999.
>>
>>If you require any further information please do not hesitate to contact me.
>>
>>Yours sincerely
>>Clare Bridle
>>
>>Short Course
>>on
>>Damage and Fracture Mechanics in Concrete, Rocks and Ceramics
>>
>>Quasi-Brittle and Disordered Materials
>>
>>
>>Presented by Prof A Carpinteri
>>Politecnico di Torino
>>
>>
>>30 June - 2 July, 1999
>>
>>Ashurst, Southampton, UK
>>
>>Wessex Institute of Technology
>>Southampton, UK
>>
>>
>>OBJECTIVES
>>
>>The course intends to introduce the audience to the fundamental
>>concepts of damage and fracture mechanics for quasi-brittle and
>>disordered materials, i.e. concrete, rocks, ceramics, without
>>excluding polymers and high strength metallic alloys.
>>
>>After presenting the basic ideas of Linear Elastic Fracture Mechanics,
>>with its energy and stress-intensification approaches, the application
>>of dimensional analysis to the critical parameters of the material
>>enables us to predict the size effects on the parameters themselves,
>>i.e., tensile strength decrease and fracture toughness increase with
>>the specimen size.
>>
>>Different causes for stress-singularity attenuation are also
>>presented, like Ramberg-Osgood strain-hardening materials and
>>re-entrant corners, for which, as a limit case, the
>>stress-intensification vanishes when the material is rigid-perfectly
>>plastic and/or the corner angle is equal to 180o (i.e. flat). Weibull
>>statistics is applied to the strength size effects and analogous
>>results are obtained considering statistical populations of
>>microdefects, with suitable distributions in shape and size, embedded
>>in linear-elastic or strain-hardening materials.
>>
>>Then, the dissipative and nonlinear phenomena at the crack tip are
>>explicitly taken into account in the second part of the course:
>>plasticity, damage and strain-softening produce a process zone where
>>linear elasticity is violated. Different nonlinear crack models are
>>proposed, each one with its mechanical and morphological
>>peculiarities.
>>
>>The cohesive crack model can be properly applied to concrete-like
>>materials and represents the restraining mechanisms in the crack tip
>>region by closing forces, which are connected with the crack opening
>>displacements through a strain-softening cohesive law. The cohesive
>>crack model may be numerically implemented and reproduce the
>>ductile-brittle structural size-transition very consistently.
>>
>>The bridged crack model (with one or n fibres) is ideal for simulating
>>rupture mechanisms in fibre-reinforced materials. When the fibre is
>>single, the model can capture the principal mechanical characteristics
>>of steel bar reinforced concrete members and provide the minimum
>>amount of reinforcement without brittle behaviour. When the fibres
>>are many, the model may be compared with the preceding cohesive one.
>>
>>The elastic interaction between macrocrack and the cloud of
>>microcracks in the process zone is also analyzed, emphasizing the
>>shielding effects due to the disorder in the microcrack distribution.
>>
>>In the third and last part of the course the disordered and multiscale
>>characteristics of the material microstructure and of the mechanical
>>damage are considered. The self-similar or self-affine morphology of
>>fracture surfaces after rupture and of ligament cross-sections at the
>>peak load are emphasized. The rough fracture surfaces may be
>>represented as invasive fractals with noninteger dimensions higher
>>than two. In this way we define a renormalized scale-independent
>>fracture energy, whereas the nominal parameter is subjected to a
>>positive scaling law.
>>
>>Analogously, the rarefied ligament cross-sections at the peak load may
>>be represented as lacunar fractals with noninteger dimensions lower
>>than two. In this way we define a renormalized scale-independent
>>tensile strength, whereas the nominal parameter is subjected to a
>>negative scaling law.
>>
>>These very novel concepts are applied to practical cases and verified
>>by experimental results. Further developments for future research are
>>also highlighted.
>>
>>COURSE PRESENTER
>>
>>Professor Alberto Carpinteri
>>Professor Alberto Carpinteri is Chairman of Structural Mechanics and
>>Director of the Laboratory of Fracture Mechanics at the Politecnico di
>>Torino, Italy. He was Visiting Professor at Lehigh University, USA,
>>in the academic year 1982-83.
>>
>>Presently he is an Active Member of New York Academy of Sciences, the
>>Chairman of ESIS Technical Committee9 on Concrete and a member of the
>>editorial board or a reviewer of various international associations
>>and publications. He has given invited courses and lectures
>>throughout Europe and in the USA, Mexico, South Africa, India, Japan,
>>Australia, China, Malaysia.
>>
>>Professor Carpinteri has authored or edited 13 books on damage and
>>fracture mechanics and published over 200 papers on international
>>journals or proceedings.
>>
>>Among the awards he has received are: the Robert l'Hermite
>>International Prize from RILEM, the Japan Society of Mechanical
>>Engineers Medal, the Doctorate of Physics H.C. from Constantinian
>>University, USA, the International Cultural Diploma of Honor from
>>American Biographical Institute, the Professorship H.C. from Nanjing
>>Architectural and Civil Engineering Institute, China. His CV is
>>currently published by the Who's Who in the World, in Science and
>>Engineering and in France and Industry.
>>
>>
>>COURSE PROGRAMME
>>
>>DAY 1: 30th June, 1999
>>
>>QUASI-BRITTLE MATERIALS
>>
>>· Griffith and Irwin approaches to fracture mechanics
>>· Application of Dimensional Analysis: size effects on tensile
>> strength and fracture toughness
>>· Different kinds of stress-singularity attenuation: strain
>> hardening materials and re-entrant corners
>>· Statistical aspects of fracture mechanics: Weibull Theory and crack
>> length distribution of self-similarity
>>
>>DAY 2: 1st July, 1999
>>
>>NONLINEAR CRACK MODELS
>>
>>· Plasticity, damage and strain-softening in the crack tip region
>>· Cohesion crack model: size effect on structural brittleness
>>· Bridged crack model: evaluation of the minimum amount of
>> reinforcement
>>· Interaction between macrocrack and microcracks in the process zone.
>>
>>DAY 3: 2nd July, 1999
>>
>>DISORDERED MATERIALS
>>
>>· Multiscale characteristics of the mechanical damage and fractal
>> approach
>>· Scaling law for fracture energy
>>· Scaling law for tensile strength
>>· Applications and further developments
>>
>>COURSE STRUCTURE
>>
>>Each day is subdivided into four sessions and will commence at 9.15am
>>and finish at 4.45pm. Lunch break is from 12.15pm to 1.45pm. Coffee
>>will be served during the breaks.
>>
>>COURSE MATERIAL
>>
>>Fees include all lecture notes, working materials, lunch, coffee, tea,
>>all computer facilities used, where applicable
>>
>>LOCATION
>>
>>The course will take place at the Wessex Institute of Technology at
>>Ashurst Lodge, which is well situated in the beautiful New Forest, but
>>is also very accessible by road, rail and air link.
>>
>>CANCELLATIONS
>>
>>Participants who cancel their registration due to special
>>circumstances up to 30 days before the course will receive a complete
>>refund minus fixed expenses. Fees remain payable in full, for
>>cancellations received within the 30 days of the start of the course
>>even if you are unable to attend or send a representative from your
>>organisation.
>>
>>ACCOMMODATION
>>
>>If you require accommodation, please contact the Course Secretariat
>>who will supply a list of local hotels on request.
>>
>>
>>Course Secretariat
>>Wessex Institute of Technology, Ashurst Lodge, Ashurst, Southampton,
>>SO40 7AA, UK Tel: 44 (0) 23 80 293223 Fax: 44 (0) 23 80 292853
>>E-Mail: cbridle@wessex.ac.uk
>>
.................
Valeria Machiunas
mmachiu@fi.uba.ar
.................