Method for detecting delamination in concrete sandwich panels

摘要

detection of delamination in the way u017celbetowych plates as delamination under test changes using the detection vibration damping plates is,in the first stage is a u017celbetowu0105 record by performing experimental modal analysis is that inspire a hammer vibration modal and during testing mode is measured at the same time, the strength of a structure and drgani transferred and the structure, and a vibration characters own alloy and is located on a placein which there is a arrow first form own vibration (1) - that means place, whose amplitude vibration in the form of vibration is the largest; and then in the designated area shall be przyu015bpieszeu0144 vibration sensor (2) preferably on the test u017celbetonowej ramp and jednoc zeu015bnie placed under u017celbetowu0105 slab system built with a lift (3),the provisional pole (4) combined przegubowo (5) from the ceiling and jacking forces, and for his help on the amplitude a0 = arch roof favourably l / 1500, where l is the span ceilingby breaking from the roof the provisional pole (4), and at the same time, record the changes in the vibration beams using previously built-up area przyu015bpieszeu0144 vibration sensor (2); in the second stage is obtained from sensor measurements by odfiltrowanie higher czu0119stotliwou015b these vibration than that corresponding to the first form of vibration and favourably twice shall be integrated over the obtained the twitchings and obtains the temporary movements of y (t) corresponding to the first form of vibration, and then determined a fraction of critical damping vibration. as a function of vibration amplitudes and with relation (1) is dependent on the amplitude dekrementem logarithmic attenuation; and sequentially creates a figure in the coordinate system. ,and showing the fraction of critical damping change with a change in the amplitude, in the third stage are interpreted obtained graph, and if a fraction of critical damping value grows on ok. 2% to the value of the right.6%, with the increase in the amplitude of vibration, and then with the further increase of the amplitude decreasing means is that the ceiling is rozwarstwiony and works in emergency, the fraction of critical damping, if does not change with the change in amplitude or change slightly with that means,the shunt plate is in good condition and fully transfers the horizontal shearing forces.