A Study Of The Identification Method Of The Local Stiffness Change Based On The Model Analysis

With the development of society and the advancement of technology, modern engineering structures toward to the direction of large and complexity. Large and complex structures event of an accident caused by the loss and impact are alarming, so the health status of the structure timely assessment has become particularly important, and injury is to identify the structural health of a key technology. In civil, mechanical and aeronautical engineering, and other fields, the use of structural dynamic change in the characterization of the injury identification, it has become a widespread concern by the research direction.In this paper we described the structural health monitoring at home and abroad technology research background, and the status and development of the application of the theory of injury. We focus on plane truss based on the vibration characteristics and modal analysis of the damage identification theory and numerical simulation. Truss structure because of its light weight, high utilization of materials, in large factories, bridges, structures have been widely used in the truss structure damage identification of practical significance, therefore, this paper plane cantilever truss structure as a research object, use of local stiffness and damaged mode changes (That is, the difference between the vibration mode for the parameters of) on the structure of the recognition, we have reached the following conclusions:(1) Bar in the same degree injury, structural changes in the frequency rate with a fixed hinge rod bearing distance from the increase reduced the same bar when the injury occurred to varying degrees, with the rate of structural change in the frequency of injury at the increase.(2) In the calculation of the bands corresponding vibration mode poor circumstances, the use of vibration to poor identification of parameters of the structural damage identification can be used to identify the location of the injury.This paper studies the grasp of the structural damage before and after change of frequency, confirmed the mode parameter is worse plane cantilever truss damage identification of sensitive parameters.