L. Nobile - Academia.edu (original) (raw)

Papers by L. Nobile

Research paper thumbnail of Influence of Cracks on the Durability of RC Structures

Key Engineering Materials, 2008

To carry out maintenance and assessment of reinforced concrete (RC) structures, a good understand... more To carry out maintenance and assessment of reinforced concrete (RC) structures, a good understanding of the effect of the change in bond behaviour of reinforcement during service life is essential. Steel reinforcement is subjected to corrosion due to carbonation and chloride attack. The former ordinarily induces uniform corrosion, the latter induces generally localised corrosion at cracks level. The existence of cracks and the crack width affect the starting points of corrosion, as indicated by the results of the exposure test carried out by Shiessl et al.[1]. Corresponding techniques, such as non-destructive in-situ testing for concrete cover thickness, permeability and the positions of the reinforcing bars, are helpful to model the real behaviour. Cracked portion around the tensile reinforcement in a flexural member can be considered to be equivalent to a concrete member having a single reinforcement subjected to pull-out force at both ends. In this paper a damage process model is proposed based on slip crack propagation in order to evaluate the effective load capacity.

Research paper thumbnail of A simplified approach for ceramic fracture toughness evaluation by indentation

Engineering Fracture Mechanics, 1995

ABSTRACT

Research paper thumbnail of Experimental Investigation on Debonding Between Masonry and Frp

Experimental Analysis of Nano and Engineering Materials and Structures, 2007

The increasing use of carbon fiber reinforced polymer (CFRP) sheets for strengthening existing re... more The increasing use of carbon fiber reinforced polymer (CFRP) sheets for strengthening existing reinforced concrete beams has generated considerable research interest in understanding the debonding mechanism of failure in such systems. Less attention has been paid on the application of the FRP technology to masonry structures and specifically in the case of restoration of historical monuments and buildings. Since this technique is, in many cases, not invasive, easy to apply and free from corrosion, its application has been ...

Research paper thumbnail of Buckling of Thin-Walled Cracked Columns

Fracture and Damage Mechanics V, 2006

Abstract In this paper, the problem of torsional buckling of a thin-walled edge cracked column, u... more Abstract In this paper, the problem of torsional buckling of a thin-walled edge cracked column, under pure bending, is studied. To the authors' knowledge, this subject has not been widely investigated in the literature. A cracked member can buckle in the plane orthogonal to the crack and out of plane triggering the Mode-III crack opening. Analytical expressions for the characteristic equation are derived for an I-beam. The influence of the crack length and position on the buckling load is investigated.

Research paper thumbnail of Micro-damage induced anisotropy in concrete

Nuclear Engineering and Design, 1995

... Article Outline. • References. ELSEVIER Nuclear Engineering and Design 156 (1995) 229234 Micr... more ... Article Outline. • References. ELSEVIER Nuclear Engineering and Design 156 (1995) 229234 Microdamage induced anisotropy in concrete Lucio Nobile m Mk Uniuersita' di Bologna, Facolta' di Ingegneria, Istituto di Scienza delle Costruzioni, Pate Risorgimento 2, 40136 ...

Research paper thumbnail of Some Recent Advances of Ultrasonic Diagnostic Methods Applied to Materials and Structures (Including Biological Ones)

Research paper thumbnail of Recent advances on non-destructive evaluation of concrete compression strength

International Journal of Microstructure and Materials Properties, 2014

The evaluation of structural performance of existing concrete structures, built according to stan... more The evaluation of structural performance of existing concrete structures, built according to standards and materials quite different to those available today, requires procedures and methods able to cover lack of data about mechanical material properties and reinforcement detailing. This issue is more relevant where seismic zones are concerned and structural strengthening is needed to prevent failures due to earthquakes. Recent seismic codes give relevance to procedure and methods to establish the performance levels of existing structures. To this end detailed inspections and testing on materials are required. As a consequence non–destructive testing (NDT) can be used in conjunction with destructive testing (DT) by a representative correlation between DT and NDT. The aim of this study is to verify the accuracy of some of the most reliable and employed formulations available in literature between measured parameters, i.e., rebound index (RI) and ultrasonic pulse velocity (UPV), and compressive strength (SonReb Method).

Research paper thumbnail of Buckling of Thin-Walled Cracked Columns

Key Engineering Materials, Nov 7, 2006

In this paper, the problem of torsional buckling of a thin-walled edge cracked column, under pure... more In this paper, the problem of torsional buckling of a thin-walled edge cracked column, under pure bending, is studied. To the authors' knowledge, this subject has not been widely investigated in the literature. A cracked member can buckle in the plane orthogonal to the crack and out of plane triggering the Mode-III crack opening. Analytical expressions for the characteristic equation are derived for an I-beam. The influence of the crack length and position on the buckling load is investigated.

Research paper thumbnail of Frp Width Effect on Shear Debonding From Concrete

Experimental Analysis of Nano and Engineering Materials and Structures, 2007

Fiber reinforced polymer (FRP) sheets have been extensively used for increasing the stiffness and... more Fiber reinforced polymer (FRP) sheets have been extensively used for increasing the stiffness and load carrying capacity of existing concrete structures. The FRP sheets are basically used as supplementary tensile reinforcement. Tensile stresses are produced in the FRP due to stresses transferred through the interfacial bond between the concrete and the FRP.

Research paper thumbnail of Experimental Investigation on Debonding Between Masonry and Frp

Experimental Analysis of Nano and Engineering Materials and Structures, 2007

The increasing use of carbon fiber reinforced polymer (CFRP) sheets for strengthening existing re... more The increasing use of carbon fiber reinforced polymer (CFRP) sheets for strengthening existing reinforced concrete beams has generated considerable research interest in understanding the debonding mechanism of failure in such systems. Less attention has been paid on the application of the FRP technology to masonry structures and specifically in the case of restoration of historical monuments and buildings. Since this technique is, in many cases, not invasive, easy to apply and free from corrosion, its application has been ...

Research paper thumbnail of Maximum circumferential stress criterion applied to orthotropic materials

Fatigue & Fracture of Engineering Materials & Structures, Sep 1, 2005

The topic of the paper is the extension of the Maximum Circumferential Tensile Stress Criterion t... more The topic of the paper is the extension of the Maximum Circumferential Tensile Stress Criterion to orthotropic materials, to obtain the crack initiation angle and the fracture loci. It includes the effects of orthotropy, load biaxiality and non-singular terms. It requires the solution of the elastostatic problem of an orthotropic plate having a central inclined crack and subjected at infinity to a uniform biaxial load. It is assumed that the crack line does not coincide with an axis of elastic symmetry of the body. The original problem has been ...

Research paper thumbnail of Crack initiation behaviour of orthotropic solids as predicted by the strain energy density theory

Theoretical and applied fracture mechanics, Oct 31, 2002

The strain energy density theory is applied to determine crack initiation in orthotropic solids. ... more The strain energy density theory is applied to determine crack initiation in orthotropic solids. An approach is used to derive the complex variable expressions of the elastic fields. The formulation is used to solve the boundary value problem by superimposing of Mode-I and Mode-II crack problems. It is shown that asymptotic expressions of the crack tip stress and displacement fields are affected by non-singular terms related to biaxial loading.

Research paper thumbnail of Strain energy density prediction of crack initiation and direction in cracked T-beams and pipes

Theoretical and applied fracture mechanics, Apr 30, 2004

In this paper, the S-theory is applied to determine crack initiation and direction for cracked T-... more In this paper, the S-theory is applied to determine crack initiation and direction for cracked T-beams and circumferentially cracked pipes. It makes use of a parameter called strain energy density factor, S, which is a function of the stress intensity factors. The strain energy density theory provides a more general treatment of fracture mechanics problems by virtue of its ability in describing the multiscale feature of material damage and in dealing with mixed mode crack propagation problem. A simple method for obtaining approximate stress ...

Research paper thumbnail of On the inclined crack problem in an orthotropic medium under biaxial loading

Engineering Fracture Mechanics, 2004

The problem of an inclined crack in an orthotropic medium under biaxial loading is analyzed. A su... more The problem of an inclined crack in an orthotropic medium under biaxial loading is analyzed. A suitable coordinate transformation is introduced and two decoupled systems of the Cauchy–Riemann type are obtained in terms of complex potentials. The crack problem is solved by using the method of analytic continuation and closed form expressions of the near tip stress and displacement fields are derived. The influence of load biaxiality on the stress intensity factors, as well as on the local stress components is studied and graphically represented. Moreover, the action of material orthotropy on various quantities describing the crack characteristic is pointed out.

Research paper thumbnail of Width effect in the interface fracture during shear debonding of FRP sheets from concrete

Engineering fracture mechanics, Mar 31, 2007

The increasing use of carbon fiber reinforced polymer (FRP) sheets for strengthening existing rei... more The increasing use of carbon fiber reinforced polymer (FRP) sheets for strengthening existing reinforced concrete beams has generated considerable research interest in understanding the debonding mechanism of failure in such systems. The influence of the width of the FRP on the load-carrying capacity is investigated in this paper. The interfacial crack propagation and strain distribution during shear debonding are studied using a full-field optical technique known as digital image correlation. The results indicate the ...

Research paper thumbnail of Finite Strip Analysis of Shells of Revolution on Discrete Supports

Developments in Computational Techniques for Civil Engineering, 1995

Research paper thumbnail of Cracked beam element formulation for structural analysis

Research paper thumbnail of Formulation and Identification Problems for Cracked Orthotropic Plates

Research paper thumbnail of Fracture response of cracked orthotropic plates

The solution of the elastostatic problem of an orthotropic body having a central inclined crack a... more The solution of the elastostatic problem of an orthotropic body having a central inclined crack and subjected at infinity to a uniform biaxial load has been employed. It is assumed that the crack line does not coincide with an axis of elastic symmetry of the body. The stress filed is reported. The topic of the present paper is the extension of the maximum Circumferential Tensile Stress Criterion to orthotropic materials, in order to obtain the crack initiation angle, pointing out the effects of orthotropy and load biaxiality. The influence of ...

Research paper thumbnail of Fracture analysis for orthotropic cracked plates

Composite structures, May 31, 2005

The present investigation is intended to study the elastostatic fracture response of an orthotrop... more The present investigation is intended to study the elastostatic fracture response of an orthotropic cracked plate subjected at infinity to a biaxial uniform load. The effects of orthotropy and load biaxiality on the near crack tip elastic fields is pointed out. Considering the non-singular terms, the angle of incipient crack propagation and the fracture loci are obtained. For this purposes the strain energy density theory and the maximum circumferential stress theory are considered and extended to orthotropic materials. A ...

Research paper thumbnail of Influence of Cracks on the Durability of RC Structures

Key Engineering Materials, 2008

To carry out maintenance and assessment of reinforced concrete (RC) structures, a good understand... more To carry out maintenance and assessment of reinforced concrete (RC) structures, a good understanding of the effect of the change in bond behaviour of reinforcement during service life is essential. Steel reinforcement is subjected to corrosion due to carbonation and chloride attack. The former ordinarily induces uniform corrosion, the latter induces generally localised corrosion at cracks level. The existence of cracks and the crack width affect the starting points of corrosion, as indicated by the results of the exposure test carried out by Shiessl et al.[1]. Corresponding techniques, such as non-destructive in-situ testing for concrete cover thickness, permeability and the positions of the reinforcing bars, are helpful to model the real behaviour. Cracked portion around the tensile reinforcement in a flexural member can be considered to be equivalent to a concrete member having a single reinforcement subjected to pull-out force at both ends. In this paper a damage process model is proposed based on slip crack propagation in order to evaluate the effective load capacity.

Research paper thumbnail of A simplified approach for ceramic fracture toughness evaluation by indentation

Engineering Fracture Mechanics, 1995

ABSTRACT

Research paper thumbnail of Experimental Investigation on Debonding Between Masonry and Frp

Experimental Analysis of Nano and Engineering Materials and Structures, 2007

The increasing use of carbon fiber reinforced polymer (CFRP) sheets for strengthening existing re... more The increasing use of carbon fiber reinforced polymer (CFRP) sheets for strengthening existing reinforced concrete beams has generated considerable research interest in understanding the debonding mechanism of failure in such systems. Less attention has been paid on the application of the FRP technology to masonry structures and specifically in the case of restoration of historical monuments and buildings. Since this technique is, in many cases, not invasive, easy to apply and free from corrosion, its application has been ...

Research paper thumbnail of Buckling of Thin-Walled Cracked Columns

Fracture and Damage Mechanics V, 2006

Abstract In this paper, the problem of torsional buckling of a thin-walled edge cracked column, u... more Abstract In this paper, the problem of torsional buckling of a thin-walled edge cracked column, under pure bending, is studied. To the authors' knowledge, this subject has not been widely investigated in the literature. A cracked member can buckle in the plane orthogonal to the crack and out of plane triggering the Mode-III crack opening. Analytical expressions for the characteristic equation are derived for an I-beam. The influence of the crack length and position on the buckling load is investigated.

Research paper thumbnail of Micro-damage induced anisotropy in concrete

Nuclear Engineering and Design, 1995

... Article Outline. • References. ELSEVIER Nuclear Engineering and Design 156 (1995) 229234 Micr... more ... Article Outline. • References. ELSEVIER Nuclear Engineering and Design 156 (1995) 229234 Microdamage induced anisotropy in concrete Lucio Nobile m Mk Uniuersita' di Bologna, Facolta' di Ingegneria, Istituto di Scienza delle Costruzioni, Pate Risorgimento 2, 40136 ...

Research paper thumbnail of Some Recent Advances of Ultrasonic Diagnostic Methods Applied to Materials and Structures (Including Biological Ones)

Research paper thumbnail of Recent advances on non-destructive evaluation of concrete compression strength

International Journal of Microstructure and Materials Properties, 2014

The evaluation of structural performance of existing concrete structures, built according to stan... more The evaluation of structural performance of existing concrete structures, built according to standards and materials quite different to those available today, requires procedures and methods able to cover lack of data about mechanical material properties and reinforcement detailing. This issue is more relevant where seismic zones are concerned and structural strengthening is needed to prevent failures due to earthquakes. Recent seismic codes give relevance to procedure and methods to establish the performance levels of existing structures. To this end detailed inspections and testing on materials are required. As a consequence non–destructive testing (NDT) can be used in conjunction with destructive testing (DT) by a representative correlation between DT and NDT. The aim of this study is to verify the accuracy of some of the most reliable and employed formulations available in literature between measured parameters, i.e., rebound index (RI) and ultrasonic pulse velocity (UPV), and compressive strength (SonReb Method).

Research paper thumbnail of Buckling of Thin-Walled Cracked Columns

Key Engineering Materials, Nov 7, 2006

In this paper, the problem of torsional buckling of a thin-walled edge cracked column, under pure... more In this paper, the problem of torsional buckling of a thin-walled edge cracked column, under pure bending, is studied. To the authors' knowledge, this subject has not been widely investigated in the literature. A cracked member can buckle in the plane orthogonal to the crack and out of plane triggering the Mode-III crack opening. Analytical expressions for the characteristic equation are derived for an I-beam. The influence of the crack length and position on the buckling load is investigated.

Research paper thumbnail of Frp Width Effect on Shear Debonding From Concrete

Experimental Analysis of Nano and Engineering Materials and Structures, 2007

Fiber reinforced polymer (FRP) sheets have been extensively used for increasing the stiffness and... more Fiber reinforced polymer (FRP) sheets have been extensively used for increasing the stiffness and load carrying capacity of existing concrete structures. The FRP sheets are basically used as supplementary tensile reinforcement. Tensile stresses are produced in the FRP due to stresses transferred through the interfacial bond between the concrete and the FRP.

Research paper thumbnail of Experimental Investigation on Debonding Between Masonry and Frp

Experimental Analysis of Nano and Engineering Materials and Structures, 2007

The increasing use of carbon fiber reinforced polymer (CFRP) sheets for strengthening existing re... more The increasing use of carbon fiber reinforced polymer (CFRP) sheets for strengthening existing reinforced concrete beams has generated considerable research interest in understanding the debonding mechanism of failure in such systems. Less attention has been paid on the application of the FRP technology to masonry structures and specifically in the case of restoration of historical monuments and buildings. Since this technique is, in many cases, not invasive, easy to apply and free from corrosion, its application has been ...

Research paper thumbnail of Maximum circumferential stress criterion applied to orthotropic materials

Fatigue & Fracture of Engineering Materials & Structures, Sep 1, 2005

The topic of the paper is the extension of the Maximum Circumferential Tensile Stress Criterion t... more The topic of the paper is the extension of the Maximum Circumferential Tensile Stress Criterion to orthotropic materials, to obtain the crack initiation angle and the fracture loci. It includes the effects of orthotropy, load biaxiality and non-singular terms. It requires the solution of the elastostatic problem of an orthotropic plate having a central inclined crack and subjected at infinity to a uniform biaxial load. It is assumed that the crack line does not coincide with an axis of elastic symmetry of the body. The original problem has been ...

Research paper thumbnail of Crack initiation behaviour of orthotropic solids as predicted by the strain energy density theory

Theoretical and applied fracture mechanics, Oct 31, 2002

The strain energy density theory is applied to determine crack initiation in orthotropic solids. ... more The strain energy density theory is applied to determine crack initiation in orthotropic solids. An approach is used to derive the complex variable expressions of the elastic fields. The formulation is used to solve the boundary value problem by superimposing of Mode-I and Mode-II crack problems. It is shown that asymptotic expressions of the crack tip stress and displacement fields are affected by non-singular terms related to biaxial loading.

Research paper thumbnail of Strain energy density prediction of crack initiation and direction in cracked T-beams and pipes

Theoretical and applied fracture mechanics, Apr 30, 2004

In this paper, the S-theory is applied to determine crack initiation and direction for cracked T-... more In this paper, the S-theory is applied to determine crack initiation and direction for cracked T-beams and circumferentially cracked pipes. It makes use of a parameter called strain energy density factor, S, which is a function of the stress intensity factors. The strain energy density theory provides a more general treatment of fracture mechanics problems by virtue of its ability in describing the multiscale feature of material damage and in dealing with mixed mode crack propagation problem. A simple method for obtaining approximate stress ...

Research paper thumbnail of On the inclined crack problem in an orthotropic medium under biaxial loading

Engineering Fracture Mechanics, 2004

The problem of an inclined crack in an orthotropic medium under biaxial loading is analyzed. A su... more The problem of an inclined crack in an orthotropic medium under biaxial loading is analyzed. A suitable coordinate transformation is introduced and two decoupled systems of the Cauchy–Riemann type are obtained in terms of complex potentials. The crack problem is solved by using the method of analytic continuation and closed form expressions of the near tip stress and displacement fields are derived. The influence of load biaxiality on the stress intensity factors, as well as on the local stress components is studied and graphically represented. Moreover, the action of material orthotropy on various quantities describing the crack characteristic is pointed out.

Research paper thumbnail of Width effect in the interface fracture during shear debonding of FRP sheets from concrete

Engineering fracture mechanics, Mar 31, 2007

The increasing use of carbon fiber reinforced polymer (FRP) sheets for strengthening existing rei... more The increasing use of carbon fiber reinforced polymer (FRP) sheets for strengthening existing reinforced concrete beams has generated considerable research interest in understanding the debonding mechanism of failure in such systems. The influence of the width of the FRP on the load-carrying capacity is investigated in this paper. The interfacial crack propagation and strain distribution during shear debonding are studied using a full-field optical technique known as digital image correlation. The results indicate the ...

Research paper thumbnail of Finite Strip Analysis of Shells of Revolution on Discrete Supports

Developments in Computational Techniques for Civil Engineering, 1995

Research paper thumbnail of Cracked beam element formulation for structural analysis

Research paper thumbnail of Formulation and Identification Problems for Cracked Orthotropic Plates

Research paper thumbnail of Fracture response of cracked orthotropic plates

The solution of the elastostatic problem of an orthotropic body having a central inclined crack a... more The solution of the elastostatic problem of an orthotropic body having a central inclined crack and subjected at infinity to a uniform biaxial load has been employed. It is assumed that the crack line does not coincide with an axis of elastic symmetry of the body. The stress filed is reported. The topic of the present paper is the extension of the maximum Circumferential Tensile Stress Criterion to orthotropic materials, in order to obtain the crack initiation angle, pointing out the effects of orthotropy and load biaxiality. The influence of ...

Research paper thumbnail of Fracture analysis for orthotropic cracked plates

Composite structures, May 31, 2005

The present investigation is intended to study the elastostatic fracture response of an orthotrop... more The present investigation is intended to study the elastostatic fracture response of an orthotropic cracked plate subjected at infinity to a biaxial uniform load. The effects of orthotropy and load biaxiality on the near crack tip elastic fields is pointed out. Considering the non-singular terms, the angle of incipient crack propagation and the fracture loci are obtained. For this purposes the strain energy density theory and the maximum circumferential stress theory are considered and extended to orthotropic materials. A ...