This special issue of IPSE contains six keynote papers selected from 45 papers presented at the 2nd International Symposium on Inverse Problems of Mechanics of Structures and Materials, called IPM 2011 in short, held in Rzeszów-Sieniawa, Poland on 27–30 April 2011. IPM 2011 was organized under the auspices of the European Community on Computational Mechanics in Applied Sciences as one of more than 20 Thematic Conferences in 2011. IPM 2009 was the first conference organized in Rzeszów-Łańcut, Poland in 2009; see the special issue of IPSE, vol. 19, 2011.
The papers presented in this special issue deal with three main topics from those discussed at IPM 2011. Three papers are devoted to the identification of damage in thin plates applying passive or active non-destructive methods of structure health monitoring.
S. Kubo, T. Sagami and S. Ioka developed a method of pasting the piezoelectric material on a cracked plate subjected to mechanical loads. The identification of cracks was carried out by means of the passive electronic potential computer tomography method.
G. Hattori and A. Sáez developed an inverse method of damage in multifield materials applying neural networks. Because of an ill-posed inverse problem, five neural networks were used for the identification of three parameters of crack damage.
P. Nazarko focused on two levels of cracks identification corresponding to novelty detection and then damage assessments. The neural networks were applied both in a decision tree and for damage and its parameters identification analyzing time records in piezoelectric transducers.
The fourth paper, by A. Poteralski et al., concerns developing a computational system for the identification of room acoustic properties. An artificial intelligence system was composed of the method of fundamental solutions and immune artificial system.
The fifth paper, written by W. Rachowicz, is devoted to the application of 3D electromagnetic fields for the analysis of an inverse medium scattering problem. What is worthy of attention is the adaptive finite element analysis in the vicinity of the scatter.
The sixth paper, written by S. Milewski and J. Orkisz, deals with an engineering problem of ground movements under a highway. A simple method of displacement measurements monitoring by stretched flexible strings placed under highway structures is worth attention.