Juan Carlos Matos Franco

• PhD
• Professor (Full) at University of Salamanca

In this paper, stress intensity factor (SIF) solutions of eccentric annular external cracks in elliptical notched round bars under tension loading have been obtained from 3D finite element analysis, along with their relation to the energy release rate obtained with the J-integral contour. The analysis variables have been the ligament diameter, its...

In this paper, a numerical modeling was developed to study (on the basis of the Paris law) the fatigue propagation paths of eccentric external (outer) cracks in circumferentially cracked round bars (CCRB) subjected to a cyclic type of loading in the form of either remote tensile loading or imposed axial displacement. Results show how the eccentrici...

In this paper, stress intensity factor (SIF) solutions are numerically obtained for notched bars subjected to tensile loading containing an eccentric circular inner crack located in the cross-section corresponding to the notch root. The finite element method and the J-integral have been used to obtain the SIF and to analyze the effect on it of thre...

This scientific article offers an innovative approach to fatigue crack growth in progressively cold drawn pearlitic steels that exhibit a microstructurally-induced tortuous propagation path (zig-zag fatigue crack path). The proposed novel approach, Toribio-González-Matos (TGM) model, consists of a modified Paris Law including the real fatigue crack...

Hydrogen-assisted fatigue crack growth (corrosion-fatigue) is studied in corner cracks emanating from holes placed in plates under tensile loading, comparing the results with those obtained in the case of fatigue in air. To this end, numerical modeling has been carried out to evaluate the crack front advance based on the Paris equation and the stre...

Crack path deflection is a phenomenon appearing in cold-drawn pearlitic steel wires as a consequence of the pearlite microstructure orientation induced by the manufacturing procedure, the deflection angle being approximately 90º, thereby representing a crack propagation step (fracture wall), a signal of splitting, delamination or debonding in the f...

This paper offers a multiscale approach (macro & micro) to the fatigue crack paths in progressively cold drawn pearlitic steels, with emphasis on the relationship between the pearlitic microstructure of the steels (progressively oriented as a consequence of the manufacturing process by cold drawing) and the fatigue behaviour at the macro- and micro...

This article studies plasticity-induced fatigue crack growth retardation in metals caused by crack path bifurcation in the near-tip region. To this end, the finite element method was used to model the crack with its bifurcated tip under several stress intensity factor (SIF) ranges. The results show the appearance of a retardation effect in the fati...

In this paper, a numerical modelling was developed to study (on the basis of the Paris law) the fatigue propagation paths of eccentric external cracks in circumferentially-cracked round bars (CCRB) subjected to axial displacement. Results demonstrate how the eccentricity (in relation to the wire axis) of the circular resistant ligament increases wi...

This article studies the plasticity-induced fatigue crack growth retardation in a steel caused by crack path deflection in the near-tip region. To this end, the finite element method was used to model the crack with its deflected kink. The results allow a calculation of the fatigue crack propagation rate for the two analyzed crack configurations, i...

This paper offers a numerical modeling of hydrogen embrittlement and notch tensile strength of high-strength pearlitic steel (supplied in the form of hot rolled bars) in the presence of blunt notches, by using the finite element method in order to determine how the notch depth influences the concentration of hydrogen in the steady-state regime for...

This article deals with the influence of the crack path branching (at the micro level) on the plasticity-induced fatigue crack growth. With regard to this, a modeling by means of the finite element method was performed considering a cracked panel subjected to tension with different symmetric and asymmetric configurations of the bifurcated crack tip...

The aim of this study is to obtain the stress intensity factor (SIF) along the crack front of elliptical cracks located in finite-thickness plates subjected to imposed displacement or applied tensile load, for different crack geometries (relative depths and aspect ratios) and crack configurations (embedded, surface, and corner). The SIF was calcula...

In this study, hydrogen-assisted fatigue propagation (a kind of corrosion fatigue phenomenon) in corner cracks at holes located in plates under tensile loading was studied, the results compared with those obtained for propagation by fatigue in air. To this end, numerical modeling was carried out for the case studied to evaluate the advance of the c...

This article studies the retardation effect in plasticity-induced fatigue crack growth rate for a low-medium strength steel, due to the appearance of microdeflections in the crack path. To this end, the finite element method was used to model the crack with its kinked tip under several stress intensity factor (SIF) ranges. The results allowed a cal...

Prestressing steel wires usually undergo cyclic loading in service. Therefore, it is of interest to analyse certain features of their mechanical behaviour under this type of loading, such as the Bauschinger effect (BE) or the hardening rule, that fit the real mechanical behaviour appropriately. In this study, different samples of high strength pear...

This paper analyses the fatigue and fracture behavior of a steel with quasi-eutectoid composition (slightly hypereutectoid) and spheroidized microstructure. The fatigue crack surface showed ductile micro-tearings produced by propagating the crack through the thin layer of proeutectoid cementite. The fracture is initiated at the fatigue crack tip in...

This paper offers a numerical approach to the problem of hydrogen embrittlement and notch tensile strength of sharply notched specimens of high-strength pearlitic steel supplied in the form of hot rolled bars, by using the finite element method in order to determine how the notch depth influences the concentration of hydrogen in the steady-state re...

This paper offers a macro- and micro-approach to locally multiaxial fatigue crack paths in oriented and non-oriented pearlitic microstructures, addressing the important role of microstructural evolution (orientation and packing closeness) during the manufacture process by cold drawing in the posterior fatigue performance of the pearlitic steel wire...

In this paper, stress intensity factor (SIF) was calculated in a bar subjected to tensile loading, considering a circular inner crack that exhibited certain eccentricity in relation to the cylinder axis. The computation was performed by means of the finite element method (FEM) using a three dimensional (3D) model and the J-integral, the analyzed va...

This paper analyzes the influence of the presence of notches on the stress intensity factor (SIF) of round bars with circumferential cracks subjected to tension loading. The finite element method (FEM) together with the computation of the J-integral were used to calculate the SIF in both the circumferentially-cracked round bar (CCRB) and the circum...

In this paper the crack path is studied for corner and surface flaws emanating from semicircular notch in plates of finite thickness subjected to cyclic tension loading. To this end, a numerical modeling was performed to evaluate the advance of the crack front on the basis of the Paris equation and the stress intensity factor solutions provided by...

In this paper, the stress intensity factor (SIF) is computed in a circumferentially cracked round bar (CCRB) subjected to applied tensile load or to imposed axial displacement, considering that the resistant ligament is circular and exhibits certain eccentricity in relation to the cylinder axis. The computation was performed by means of the finite...

In this paper the important role of manufacturing by progressive cold drawing on initiation and propagation of fatigue cracks in cold-drawn pearlitic steel wires is addressed by analyzing the initiation (from surface defects) and propagation of fatigue cracks in two pearlitic steels with very different cold drawing degree or cumulative plastic stra...

This article deals with the computational modelling of the fatigue crack aspect ratio evolution in embedded, surface, and corner cracks located in finite-thickness plates under tensile fatigue. The approach is based on the Paris law for fatigue propagation and an expression for the stress intensity factor (SIF) provided by Newman and Raju. Numerica...

In this paper, the stress intensity factor (SIF) is computed in a circumferentially-cracked round bar (CCRB) subjected to tensile loading, considering that the resistant ligament is circular and exhibits certain eccentricity in relation to the cylinder axis. The computation was performed by means of the finite element method (FEM) using a three dim...

This article deals with the locally multiaxial fatigue behaviour of high strength steel. To this end, the influence of the cracking path deflections (at the micro level) on the plasticity-induced fatigue crack growth is analyzed. With regard to this, a modelling by means of the finite element method was performed for a given stress intensity factor...

The aim of this paper is the numerical prediction of the cracking path followed by a surface crack front in plates constituted of different materials (determined by the exponent m of the Paris law), subjected to cyclic tension or cyclic bending loading. To this end, a numerical modelling was developed on the basis of the discretization of the crack...

In this paper, a Paris law-based model is presented whereby crack propagation occurs under cyclic loading in air (fatigue) and in an aggressive environment (corrosion-fatigue) for the case of corner cracks (with a wide range of aspect ratios in the matter of the initial cracks) in finite-thickness plates of 316L austenitic stainless steel subjected...

The role of different residual stress profiles in the fatigue crack growth is studied in prestressing steel wires under tension loading or bending moment. The crack front evolution is analyzed by means of a computer program on the basis of the Walker law. Numerical results indicate that the absence of residual stresses makes the crack propagate fol...

This paper analyzes the fatigue crack path in two pearlitic steels with very different microstructural arrangement: a hot rolled pearlitic steel bar and a commercial high-strength cold drawn prestressing steel wire frequently used for anchorage in rocks. In both materials, fatigue cracks are mostly transcollonial and tend to fracture pearlitic lame...

This article deals with the relationship between the microstructure and both strength and ductility in eutectoid pearlitic steel. It is seen how standard mechanical properties and fracture micromechanisms are affected by heat treatment and the resulting microstructure in the material. The yield stress, the ultimate tensile strength and the ductilit...

This paper analyses the role of cold drawing in the fatigue and fracture behaviour of pearlitic steels with distinct drawing degree (a hot rolled bar and a commercial prestressing steel wire). Fatigue crack growth develops globally in mode I and locally in mixed mode in both steels, the micro-crack deflection angle depending on the drawing degree....

In this paper a study is presented of the tensile fracture behavior of progressively-drawn pearlitic steels obtained from five different cold-drawing chains, including each drawing step from the initial hot-rolled bar (not cold-drawn at all) to the final commercial product (pre-stressing steel wire). To this end, samples of the different wires were...

This paper presents a fracture mechanics approach to the phenomenon of fatigue crack propagation in geometries such as plates and sheets. The aim is to analyze the crack path (aspect ratio evolution) in a wide range of engineering materials (characterized by different values of the m-parameter of the Paris law) and subjected to two kinds of cyclic...

This paper deals with the effect of several residual stress profiles on the fatigue crack propagation in prestressing steel wires subjected to tension loading or bending moment. To this end, a computer program was developed to evaluate the crack front evolution on the basis of the Walker law. Results demonstrate that the absence of residual stresse...

In this paper, a fracto-metallographic analysis was performed on the cracked specimens of cold drawn pearlitic steel subjected to fatigue tests. Fatigue cracks are transcollonial and exhibit a preference for fracturing pearlitic lamellae, with non-uniform crack opening displacement values, micro-discontinuities, branchings, bifurcations and frequen...

This paper analyzes the overload retardation effect (ORE) on the fatigue crack growth (FCG) of cold drawn prestressing steel when different loading sequences are used. The ORE is more intense for elevated load decrease or for low initial stress intensity factor (SIF) range ΔK0. A transient stage can be observed in the Paris curve (da/dN-ΔK) when th...

This paper deals with the influence of the cold drawing process on the fracture behaviour of pearlitic steels. To this end, fracture tests under axial loading were performed on steel wires with different drawing degree (from a hot rolled bar to a commercial prestressing steel wire), transversely pre-cracked by fatigue, analyzing in detail the chang...

The aim of this paper is to calculate how the surface crack front and the dimensionless compliance evolve in cylindrical bars containing a transverse edge crack subjected to cyclic tension or bending with different initial crack geometries (crack depths and aspect ratios). A Java computer program was developed and implemented to obtain the crack pa...

The aim of this paper is the numerical prediction of the cracking path followed by a surface crack front in plates constituted of different materials (determined by the exponent m of the Paris law), subjected to cyclic tension or cyclic bending loading. To this end, a numerical modelling was developed on the basis of a discretization of the crack f...

This paper analyzes the propagation of fatigue cracks in pearlitic steel supplied in two forms, hot rolled bar and prestressing steel wire. The experimental procedure consisted of fatigue tests on cylindrical bars under tensile loading, using steps with decreasing amplitude of stress intensity factor and constant stress intensity range during each...

This paper analyses how the microstructure of an eutectoid pearlitic steel affects its conventional mechanical properties (obtained by means of a standard tension test) and the associated micromechanisms of fracture. Results show how the yield strength, the ultimate tensile strength (UTS) and the ductility, increase as the continuous cooling rate r...

The aim of this paper is to calculate how the surface crack front and the dimensionless compliance evolve in cracked cylindrical bars subjected to cyclic tension or bending with different initial crack geometries (crack depths and aspect ratios). To this end, a computer application (in the Java programming language) that calculates the crack front’...

This paper analyzes the propagation of fatigue cracks in pearlitic steel presented in two forms: as a hot rolled bar and as a cold drawn wire. The experimental procedure consisted of fatigue tests on cylindrical bars under tensile loading, using steps with decreasing amplitude of stress and constant stress range during each step. Results show how t...

Tensile fatigue tests were performed under load control, with constant stress range Δσ on pearlitic steel wires, from the hot rolled bar to the commercial prestressing steel wire (which has undergone seven cold drawing steps). Results show that fatigue cracks in pearlitic steels initiate at the wire surface starting from small defects, whose size d...

This paper analyses how the microstructure influences the fracture behaviour of a steel with quasi-eutectoid composition (slightly hypereutectoid) and pearlitic microstructure, when subjected to different spheroidization processes by means of isothermal treatment of pearlite at 700 ºC and different spheroidization times. Results indicate that the f...

This paper shows the evolution of the surface crack front in round bars constituted of different materials (determined by the exponent m of the Paris law), subjected to fatigue tension loading (with free ends) or fatigue bending loading. To this end, a numerical modelling is developed on the basis of a discretization of the crack front (characteriz...

This paper studies the relationship between the microstructural changes caused by the cold drawing process in pearlitic steel wires (axial orientation of the pearlitic lamellae together with decrease of the average interlamellar spacing) and the improvement of their mechanical properties. The strength is related to plastic strain by means of the Em...

The aim of this paper is the numerical prediction of the cracking path followed by a surface crack front in plates constituted of different materials (determined by the exponent m of the Paris law), subjected to cyclic tension or cyclic bending loading. To this end, a numerical modelling was developed on the basis of a discretization of the crack f...

This paper analyzes the propagation of fatigue cracks in pearlitic steel supplied in two forms, hot rolled bar and prestressing steel wire. The experimental procedure consisted of fatigue tests on cylindrical bars under tensile loading, using steps with decreasing amplitude of stress intensity factor and constant stress intensity range during each...

Steels with pearlitic microstructure exhibit strength anisotropy after cold drawing to increase the yield stress by a strain hardening mechanism. Such anisotropy manifests itself in the form of mixed mode propagation associated with crack deviation tending to axial growth following a path quasi-parallel to the wire line (drawing axis) due to the dr...

In this paper, bolted joints were subjected to fatigue testing under load control with R-ratio equal to zero. Fatigue fracture surfaces show a crescent moon geometry for short cracks turning into quasi-straight fronts for long cracks. Fatigue cracking usually starts on the bolt’s first notch root inside the bolted joint, secondary cracks appearing...

In this paper, tensile fatigue tests were performed under load control, with constant stress amplitude, on pearlitic steel wires with different cold drawing degree, from the hot rolled bar (not cold drawn at all) to the commercial prestressing steel wire (which has undergone seven cold drawing steps and a stress relieving treatment). Results show t...

The aim of this paper is to calculate how the surface crack front and the dimensionless compliance evolve in cracked cylindrical bars subjected to cyclic tension or bending with different initial crack geometries (crack depths and aspect ratios). To this end, a computer application (in the Java programming language) that calculates the crack front'...

This paper analyzes the propagation of fatigue cracks in pearlitic steel in two forms, hot rolled bar and cold drawn wire. The experimental procedure consisted of fatigue tests on bars under tensile loading, using steps with decreasing amplitude of stress and constant stress range during each step. The curves plotting cyclic crack growth rate versu...

This paper analyzes the tensile fatigue behaviour of bolted joints constituted by commercial steel bolts. They were tested under both monotonic and fatigue tensile loading, with different R-ratio. Results show that under increasing monotonic tensile loading the bolted joint is not the failure zone of the bolt, whereas such a bolted joint is the fai...

This paper shows the evolution of the surface crack front in round bars constituted of different materials (determined by the exponent m of the Paris law), subjected to fatigue tension loading (with free ends) or fatigue bending loading. To this end, a numerical modeling was developed on the basis of a discretization of the crack front (characteriz...

We present the evolution of the surface crack front in prestressing reinforced-concrete steel wires subjected to fatigue in air and to corrosion fatigue in Ca(OH)2 + NaCl. To this end, a numerical modeling was performed on the basis of discretization of the crack front (with elliptic shape) by considering that the crack advance at each point is per...

Cold-drawn prestressing steel wires exhibit strength anisotropy in the form of fracture path deflection towards a direction approaching the wire axis, or cold drawing line, as a consequence of the pearlitic microstructure orientation induced by the manufacturing procedure. Such a crack path deflection is initiated at certain nuclei (fracture origin...

This paper analyzes the effect produced by sudden load changes on the fatigue of cold drawn prestressing steel wires to be used in prestressed concrete. Fatigue tests were performed on cylindrical samples under load control, using fatigue steps with different stress, and observing the appearance of a transient state in the fatigue crack propagation...

This paper analyzes the effect produced by sudden load changes on the fatigue of cold drawn prestressing steel wires to be used in prestressed concrete. Fatigue tests were performed on cylindrical samples under load control, using fatigue steps with different stress, and observing the appearance of a transient state in the fatigue crack propagation...

This paper studies the dimensionless compliance in cylindrical geometries with transverse surface cracks subjected to axial tensile loading. Compliance evolution is analyzed when round bars are subjected to fatigue with free and constrained sample ends, initial crack geometries of straight or circular fronts and several materials characterized thro...

Numerical analyses of plasticity-induced fatigue crack growth (FCG) were performed for high-strength steels. FCG proceeds by large crack tip deformations promoting transfer of material from the tip apex to the crack flanks, thus rendering plastic crack growth based on plastic deformations without bond breaking or material splitting at the crack tip...

In this paper the influence of microstructure on fatigue crack growth was analysed in steel with slightly hypereutectoid composition. A material constituted of pearlite colonies and a thin layer of proeutectoid cementite (pearlitic steel) was studied in its initial condition (as received). In addition, the same material was analyzed after undergoin...

This paper shows the evolution of the surface crack front in prestressing steel wires subjected to fatigue in air and to corrosion-fatigue in Ca(OH)2+NaCl. To this end, a numerical modelling was made on the basis of a discretization of the crack front (characterized with elliptical shape), considering that the crack advance at each point is perpend...

In the conceptual framework of fracture mechanics analyses, the study of cracked wires axially loaded has the highest interest since numerous structural elements (e.g. wires, cables, cordons or tendons) work under such a type of loading during their service lives. So, a method that allows the determination of stress states at the crack front should...

This paper analyzes the evolution of Vickers micro-hardness in progressively drawn eutectoid steels focussing the study on the characteristic sections of the wires. The average value of the Vickers micro-hardness was calculated for each section according to its symmetry, thus studying the variation of these values with cold drawing. The indentation...

This paper analyses the differences in fracture behaviour of two cold drawn pearlitic steels with different degree of strain hardening: a slightly drawn bar and a heavily drawn wire. The load-displacement curve F-u was analysed in the two cases, with special emphasis in the characteristic points of the plot: the load defining the end of linear beha...

This paper analyses the influence of microstructural anisotropy of a progressively drawn pearlitic steel (orientation of pearlitic lamellae in the drawing direction) on the microscopic and macroscopic evolution of cracking paths produced by fatigue and fracture. The fatigue crack path is always contained in the transverse section of the wires, i.e....

The paper presents an analysis of the failure in service of a lifting platform used for tree pruning. Different fracture mechanics techniques were used to reveal the causes of failure such as analysis of the fracture surface, mechanical and microstructural characterization of the material and fracture mechanics tests to determine the critical value...

This paper analyzes the evolution of Vickers micro-hardness in progressively drawn eutectoid steels focussing the study on the characteristic sections of the wires. The average value of the Vickers micro-hardness was calculated for each section according to its symmetry, thus studying the variation of these values with cold drawing. The indentation...

This paper deals with the role of microstructure on the fatigue behaviour of pearlitic steels with different degrees of cold drawing. The analysis is focussed on the region II (Paris) of the fatigue behaviour, measuring the constants (C and m) for the different degrees of drawing. From the engineering point of view, the manufacturing process by col...

In this paper different stress intensity factor (SIF) solutions numerically obtained by previous researchers on transversely cracked cylinders subjected to tension loading are analyzed. Solutions are compared in the matter of stress intensity values at the centre of the crack front and at the external surface of the cylinder, and a wide range of cr...

This paper proposes a numerical procedure for calculating the crack shape evolution in semielliptic surface flaws in round bars under tensile loading, studying how the aspect ratio (relation between the semiaxes of the ellipse) changes with the relative crack depth. It was been assumed that each point at the crack front advances in direction perpen...

In this paper we address the problem of waste recycling in the province of Zamora. The recycling process requires the collection of the waste in an efficient way. This leads to the mathematical problem of vehicle routing, or some particular case of it, to define the optimal paths to collect the waste. This paper presents the application of artifici...

In this paper an automatic (analytical-numerical) procedure is proposed to model the front of a transverse surface crack located in the circular section of a lineal structural element (wire, cable, strand, rod, shaft,..., i.e., a cylindrical geometry) by means of a fitting ellipse, obtaining the ellipse parameters from a series of points in the rea...

Description Forty-two peer reviewed papers present the latest research in: • Residual stress effects on fatigue and fracture • Multiscale and physics-based approaches • Reactor components and materials • Fatigue crack growth • Predicting the effects of elevated temperatures and environment • Fatigue and fracture of specific components, joining meth...

This paper deals with the influence of the manufacturing process on the fatigue behavior of pearlitic steels with different degrees of cold drawing. The fatigue crack growth rate (da/d/V) is related to the stress intensity range (AK) by means a compliance method to evaluate the crack depth a in the samples at any instant during the tests. The analy...

This paper deals with the influence of the manufacturing process on the fatigue behaviour of pearlitic steels with different degrees of cold drawing. The analysis is focussed on the region II (Paris) of the fatigue behaviour in which da/dN=C (∆K)m, measuring the constants (C and m) for the different degrees of drawing. From the engineering point of...

This paper analyzes how the cold drawing process influences the fatigue behaviour of eutectoid steel, with special emphasis on the role of microstructural changes induced during such a manufacturing process. Fatigue cracks are transcollonial and exhibit a preference for fracturing pearlitic lamellae, with non-uniform crack opening displacement valu...

This paper deals with the fatigue crack growth in pearlitic steel wires in the form of hot rolled bar and cold drawn wire. The progress of crack front was analysed by means of the evolution of the aspect ratio with the relative crack depth, and this latter was evaluated during the tests by a compliance method. Results show that cold drawing is bene...

This paper analyzes how the cold drawing process influences the fatigue behaviour of eutectoid steel, with special emphasis on the role of microstructural changes induced during such a manufacturing process. Fatigue cracks are transcollonial and exhibit a preference for fracturing pearlitic lamellae, with non-uniform crack opening displacement valu...

Cold-drawn prestressing steel wires exhibit strength anisotropy in the form of fracture path deflection towards a direction approaching the wire axis, or cold drawing line, as a consequence of the pearlitic microstructure orientation induced by the manufacturing procedure. Such a crack path deflection is initiated at certain nuclei (fracture origin...

The Rural Postman Problem consists of finding a shortest tour containing all edges in a subset, in the subgraph induced by some subset of nodes. In general, the problem is NP-hard, since the Traveling Salesman Problem can be easily transformed into it. The Traveling Salesman Problem consist of finding a shortest closed tour which visits all the cit...

RESUMEN Este artículo propone una modelización numérica de la evolución de un frente de fisura semielíptico en geometrías cilíndricas, e.g. alambres, bajo solicitación cíclica axial, estudiando como varía el factor de aspecto (relación entre semiejes de la elipse) con la profundidad de fisura relativa. Para ello se ha considerado que cada punto del...

This paper analyzes, by means of materialographic techniques and fracture test arrest, the cracking path in progressively drawn pearlitic steels. In slightly drawn steels, the fatigue precrack exhibits, as the applied load increases during the test, crack tip blunting and increase of crack opening displacement (COD) up to the appearance of the clea...

This paper analyzes how the cold drawing process influences the fatigue behaviour of eutectoid steel, with special emphasis on the role of microstructural changes induced during such a manufacturing process. Fatigue cracks are transcollonial and exhibit a preference for fracturing pearlitic lamellae, with non-uniform crack opening displacement valu...

This paper analyzes the evolution of Vickers micro-hardness in progressively drawn eutectoid steels analyzing such a micro-hardness on the characteristic sections of the wires. The average value of the Vickers micro-hardness was calculated for each section according to its symmetry, thus studying the variation of these values with cold drawing. The...

In the framework of damage tolerance analyses in structural engineering, a problem of major concern is the formulation of a fracture criterion useful for engineering design against catastrophic failure. This is particularly important in the case of high-strength structural members in the form of bars, wires, strands, tendons and cables (e.g., high-...

This paper deals with the fatigue crack growth in pearlitic steel wires in the form of hot rolled bar and cold drawn wire. The progress of crack front was analysed by means of the evolution of the aspect ratio with the relative crack depth, apart from the symmetry of growth, for different initial crack shapes. The linear elastic uniform zone in the...

Resumen. En este artículo se presenta un estudio del comportamiento en fractura de aceros perlíticos progresivamente trefilados, desde el alambrón inicial laminado en caliente hasta el alambre de pretensado comercial (producto final) fuertemente trefilado. Para ello se han tomado muestras de los distintos aceros para su fractura mediante un ensayo...

Este libro está basado en la colección de problemas que hemos utilizado en las clases prácticas, así como los que hemos ido planteando en los exámenes de las asignaturas de Informática básica existentes en las distintas titulaciones de Ingeniería en la Escuela Politécnica Superior de Zamora en la Universidad de Salamanca. A lo largo de los años dur...

In this paper an automatic (analytical-numerical) procedure is proposed to model the front of a surface crack in a lineal structural element (wire, cable, strand, rod, shaft,...), obtaining the ellipse parameters from a series of points in it and adjusting them by a least square method. For symmetric cracks two modelling procedures are formulated:...

Prestressing steels usually work under cyclic loading during their service life, so that it is interesting to analyse diverse characteristics of the mechanical behaviour of these steels under this type of loading such us the so-called Bauschinger effect or the hardening rule fitting better the real behaviour of material in the plastic regime. In th...