Damage and structural restoration effect in the calculation of structural natural vibration frequencies of petroleum vapor plant

abstract a vapor plant belongs to the petroleum industry of the oriental coast of maracaibo lake, zulia state of venezuela. the structure of the plant is conformed by a frame of two floors that supports in the second roof two tanks of water with weight of 50 tons each one. the floors have several links with diverse pipes that transport water and vapor. although the structure was already built at the beginning of the decade of the 1980, at the commencement of the 2000 year, it was out of operation because its maintenance was very deficient and with inadequate procedures. this paper proposed a methodology for the repair of the structure, and were calculated experimentally and theoretically the natural vibration frequencies of the structure before and after the repair, with the purpose of obtaining a theoretical relationship of the initial damage of the structure and then to be able to quantify the increment of rigidity of the frame after having repaired