Storage tanks are always under different hazards such as corrosion and leaking. In this work we have introduced a computational analysis on storage tanks in which a real-time yet efficient monitoring technique using Fiber Bragg Grating (FBG) sensors for corrosion detection on the bottom plate and vibration monitoring on outer surfaces of storage tanks is proposed. A finite element model for the tank is developed, in which the outer tanks surfaces are considered as plate elements and FBG sensors as beam elements. An array of FBG sensors is utilized to compute the generated strain in the FBGs due to losing thickness in the tank's bottom plate and due to vibration on the outer surfaces in finite element model. The strain is then used to measure the change in wavelength of FBG sensors. An array of FBGs is considered beneath the bottom plate to accurately detect the damage when it is lie on the fibers and/or between the fibers. Measuring wavelength change clearly presents the mode shape of the plates due to vibration. It is observed that the change in wavelength in FBGs is a good indicator of the lost thickness of the plate as well as vibration and shape monitoring.