"A simple procedure is presented for the determination of a Periodic Unit Cell (PUC) for a masonry structure made of non-periodically distributed bricks of various sizes and shapes. Such a unit cell, in order to be statistically representative, is derived by matching geometrical statistics related to the original structure and the idealized unit cell. The required input data are obtained from digitized photographs of real historical structures. The parameters of the unit cell then follow from a minimization problem, defined in terms of properly selected statistical descriptors such as the two-point probability function. The resulting optimization problem is efficiently solved by a global optimization technique based on genetic algorithms. The quality of the periodic unit cell is judged by numerical evaluation of effective elastic properties. In this work, three alternative algorithms are considered. The first one is based on well-developed techniques of mathematical homogenization of p."@en . . "Homogenizace n\u00E1hodn\u00FDch zd\u011Bn\u00FDch konstrukc\u00ED - porovn\u00E1n\u00ED numerick\u00FDch metod"@cs . "Nov\u00E1k, Jan" . . . "Hashin-Shtrikman variational principles; Lipman-Schwinger equation; finite element method; masonry structures; mathematical homogenization; random heterogenous media; statistically optimized unit cell"@en . "RIV/68407700:21110/04:01099171!RIV07-GA0-21110___" . . "Zeman, Jan" . "566637" . . . . . "Homogenization of Random Masonry Structures - Comparison of Numerical Methods" . "EM 2004 - 17th ASCE Engineering Mechanics Division Conference" . "2004-06-13+02:00"^^ . . "University of Delaware" . . . . "A simple procedure is presented for the determination of a Periodic Unit Cell (PUC) for a masonry structure made of non-periodically distributed bricks of various sizes and shapes. Such a unit cell, in order to be statistically representative, is derived by matching geometrical statistics related to the original structure and the idealized unit cell. The required input data are obtained from digitized photographs of real historical structures. The parameters of the unit cell then follow from a minimization problem, defined in terms of properly selected statistical descriptors such as the two-point probability function. The resulting optimization problem is efficiently solved by a global optimization technique based on genetic algorithms. The quality of the periodic unit cell is judged by numerical evaluation of effective elastic properties. In this work, three alternative algorithms are considered. The first one is based on well-developed techniques of mathematical homogenization of p." . "Homogenization of Random Masonry Structures - Comparison of Numerical Methods"@en . . . "Newark" . . "Newark" . "RIV/68407700:21110/04:01099171" . "Homogenizace n\u00E1hodn\u00FDch zd\u011Bn\u00FDch konstrukc\u00ED - porovn\u00E1n\u00ED numerick\u00FDch metod"@cs . "[A5C0188378DE]" . . . . "Homogenization of Random Masonry Structures - Comparison of Numerical Methods" . "8"^^ . "P(GA103/04/1321), P(GP103/01/D052), P(GP103/04/P254)" . . "3"^^ . . "1 ; 8" . "3"^^ . "21110" . "Homogenization of Random Masonry Structures - Comparison of Numerical Methods"@en . "\u0160ejnoha, Michal" . . . . . "Tento p\u0159\u00EDsp\u011Bvek porovn\u00E1v\u00E1 t\u0159i p\u0159\u00EDstupy k modelov\u00E1n\u00ED zd\u011Bn\u00FDch konstrukc\u00ED s nepravidelnou strukturou. Prvn\u00ED z nich je zalo\u017Een na definici periodick\u00E9 jednotkov\u00E9 bu\u0148ky, kter\u00E1 optim\u00E1ln\u011B aproximuje p\u016Fvodn\u00ED strukturu ve smyslu dvojbodov\u00E9 pravd\u011Bpodobnosti. Druh\u00FD vyu\u017E\u00EDv\u00E1 roz\u0161\u00ED\u0159en\u00FDch Hashin-Shtrikmanov\u00FDch varia\u010Dn\u00EDch princip\u016F; t\u0159et\u00ED je zalo\u017Een na rychl\u00E9 Fourierov\u011B transformaci."@cs .