Variations in mode shape for sensor placement in health monitoring systems

A generalization for a two-tier approach to damage identification based on structural performance and levels or magnitude of damage is presented. The two tiers are defined as health or damage monitoring and situation assessment. Damage monitoring involves the inspection of a structure for continual degradation caused by accumulated damage. Situation assessment results from a known incident with a high probably of damage. Initial work on damage monitoring of structural components examines the response of a flat plate as the first step in a series of analyses that will address more complex structures. Damage is included in the computational study in the form of damage to joints such as weld lines. Trends in local and global responses have been evaluated in order to develop an understanding of the implications of varying amounts of damage in the joints on structural response. Numerical based visualization techniques are used to isolate regions of mode shape variation with increasing damage. Implications and use of the developed techniques for monitoring and sensor placement requirements are noted.