Experimental Research on the Static and Dynamic Damage Detection of Prestressed Concrete beam

Through the static and dynamic test of three model beams, the damage identification method of combining the static and dynamic parameters was introduced and the damage of the beams can be effectively identified by this method. The research shows that the change of static stiffness of the model beams is more sensitive than the change of dynamic stiffness tested after unloading, but both of the trends are basically the same. The relationship of the static stiffness of each experimental beam K and first natural frequency omega can be expressed by K=m omega(2)+n, namely both can be an alternative. Parameters m, n are related to the characteristics of beams, and the inherent elastic modulus, stiffness, reinforcement ratio of beams are smaller, whose m value is tend to be big while the n value is tend to be small. The low-order frequency and static load deflection of structure or component in engineering can be relatively easy accessed. The method of combining the static and dynamic can be used to make up for the reference state data need to refer to the flaw in the damage detection, especially which has important practical significance for the online real-time health monitoring of the structure.