Analysis of Compatibility with Experimental Data of Fractal Descriptions of the Fracture Parameters

In order to check if the Fractal theory could be a useful tool for some quantitative descriptions of the fracture parameters, the present work studied different theoretical models (e.g. the Bazant’s Size Effect Law (SEL) [1], the Modified Size Effect Law [2,3] and the Carpinteri’s MultiFractal Scaling Law (MFSL) [4] of the fracture parameters of concrete specimen, and the compatibility of some of the above studied theoretical models relative to the experimental data, using certain recent procedures to study the global and local compatibility. The fracture parameters can be considered as main quantities for computational procedures for modeling the fracture of a certain ensemble (a suddenly emerging phenomena). In the next phase, the thermoelastic generation of ultrasonic perturbations in semitransparent solids was analyzed (using computer simulation) so as to find similarities with material properties as fractal dimensions, when the heat source is a laser radiation. The algorithm, the numerical analysis has taken into account three main physical phenomena: the absorption of electromagnetic energy in substance with heat generation; thermal diffusion with electromagnetic energy based heat source and elastodynamic wave generation by thermoelastic expansion.

[1]  Konstantin L. Vodopyanov,et al.  GHz ultrasound wave packets in water generated by an Er laser , 1998 .

[2]  Peter W. M. John Statistical Methods in Engineering and Quality Assurance , 1990 .

[3]  Marek Rybaczuk,et al.  The concept of physical and fractal dimension II. The differential calculus in dimensional spaces , 2001 .

[4]  D. Marquardt An Algorithm for Least-Squares Estimation of Nonlinear Parameters , 1963 .

[5]  Peter Hess,et al.  Linear and Nonlinear Elastic Surface Waves: From Seismic Waves to Materials Science , 2002 .

[6]  B. Mandelbrot Fractal Geometry of Nature , 1984 .

[7]  M. D. Hersey,et al.  Introduction to the theory of similarity , 1965 .

[8]  Jacky Mazars,et al.  Size Effect in Brazilian Split-Cylinder Tests: Measurements and Fracture Analysis , 1991 .

[9]  Roland Oltra,et al.  Simultaneous laser generation and laser ultrasonic detection of the mechanical breakdown of a coating–substrate interface , 2001 .

[10]  Alberto Carpinteri,et al.  Size effects on concrete fracture energy: dimensional transition from order to disorder , 1996 .

[11]  D. R. Cox,et al.  Theory and practice of the evaluation of measurements , 1966 .

[12]  Jin-Keun Kim,et al.  Size effect in concrete specimens with dissimilar initial cracks , 1990 .

[13]  Z. Bažant Size Effect in Blunt Fracture: Concrete, Rock, Metal , 1984 .

[14]  Alberto Carpinteri,et al.  Scaling behaviour and dual renormalization of experimental tensile softening responses , 1998 .

[15]  L. Jacobs,et al.  Guided Lamb Wave Propagation in Composite Plate/Concrete Component , 2002 .

[16]  Marek Rybaczuk,et al.  The concept of physical and fractal dimension I. The projective dimensions , 2001 .

[17]  Alberto Carpinteri,et al.  Fractal nature of material microstructure and size effects on apparent mechanical properties , 1994 .

[18]  B. Mandelbrot,et al.  Fractal character of fracture surfaces of metals , 1984, Nature.

[19]  Kenneth Levenberg A METHOD FOR THE SOLUTION OF CERTAIN NON – LINEAR PROBLEMS IN LEAST SQUARES , 1944 .