"596945" . . "2003-12-03+01:00"^^ . . "Vysok\u00E9 u\u010Den\u00ED technick\u00E9 v Brn\u011B" . "6"^^ . . . . . "26220" . "80-7204-318-8" . "Proceedings of the Workshop NDT CMC 2003 Non-Destructive Testing of Civil Materials and Constructions" . "2"^^ . . "2"^^ . "Brno" . . "Brno" . "RIV/00216305:26220/03:PU39252" . . . . . . . "When a stress is applied to the solids (rocks or tiles) cracks creation can be detected by signals of an acoustic and electromagnetic emission. The experimental study has been performed on rock samples. Two metallic layers have covered the tested devices to create metal-insulator-metal structure. During the process of the crack generation the electric charges appeared at the faces of the cracks. The electric dipole system is a source of voltage induced on metal electrodes. Using Shockley-Ramo theorem, the differential equation for induced voltage is derived. We found that voltage on measuring capacitor is directly proportional to the dipole width and its active area. The recorded electric signal is superposition of crack walls \u201Cself\u201D vibration given by crack length and vibration due to an ultrasonic wave given by sample dimensions. The electromagnetic signal precedes the acoustic emission response and time delay corresponds to the difference of propagation velocities of sound and electromagnetic r" . . "A Model for an Electromagnetic signal Generated by Crack Creation in Solids" . "A Model for an Electromagnetic signal Generated by Crack Creation in Solids" . "[48B6123232EF]" . . "RIV/00216305:26220/03:PU39252!RIV11-MSM-26220___" . . "P(GA103/01/1058), P(GP102/02/D073), V, Z(MSM 261100007), Z(MSM 262200022)" . "Koktav\u00FD, Pavel" . . "When a stress is applied to the solids (rocks or tiles) cracks creation can be detected by signals of an acoustic and electromagnetic emission. The experimental study has been performed on rock samples. Two metallic layers have covered the tested devices to create metal-insulator-metal structure. During the process of the crack generation the electric charges appeared at the faces of the cracks. The electric dipole system is a source of voltage induced on metal electrodes. Using Shockley-Ramo theorem, the differential equation for induced voltage is derived. We found that voltage on measuring capacitor is directly proportional to the dipole width and its active area. The recorded electric signal is superposition of crack walls \u201Cself\u201D vibration given by crack length and vibration due to an ultrasonic wave given by sample dimensions. The electromagnetic signal precedes the acoustic emission response and time delay corresponds to the difference of propagation velocities of sound and electromagnetic r"@en . "Koktav\u00FD, Bohumil" . "A Model for an Electromagnetic signal Generated by Crack Creation in Solids"@en . "A Model for an Electromagnetic signal Generated by Crack Creation in Solids"@en . . . "Crack, Electric charge, Electromagnetic emission, Acoustic emission"@en . . . .