THEORY and MODEL EXPERIMENT of SMART PRESTRESSED BEAM
Based on the high ratio of live load to dead load, this paper presents using smart prestressing in the beam, which can change the value of prestressing under different live load. According to the live load on the beam, the deformation and strain of smart prestressed beam can be controlled in the design range if the beam is collocated with suitable telescopic mechanisms, which can change the value of prestressing in the smart beam by means of propping up or drawing back telescopic mechanisms. The deformation of a steel beam model, which uses analog signals control system and regards mid-span deformation as its control aim, is analyzed to show the whole function course of prestressing in the beam under three typical locomotive loads. The result of experiment validated the feasibility of smart prestressing control theory.