Analysis of Inhomogeneous Structural Monitoring Data

Bok av Werner Lienhart
Today, deformation measurements are not the sole competence of surveyors anymore as geodetic sensors (tacheometers, GPS, etc.) are commonly used simultaneously with sensors of other disciplines. Although, the combined analysis appears straight forward at the first glance, problems arise when connection measurements between spatially distributed sensors are missing. Furthermore, in practice the measurements of different sensor types are often carried out by different groups and are rarely made simultaneously. The general situation is therefore given by spatially distributed measurements of different types and scattered in time.In this thesis an Integrated Analysis Method (IAM) is proposed which allows the use of spatially distributed, hybrid measurements taken at different times in combination with a Finite Element Model (FEM). With the proposed method it is possible to separate deformations caused by regular changes (e.g. temperature changes) from deformations induced by damage (e.g. cracks, material deterioration). The generic method can be applied to inhomogeneous monitoring data of any structure as long as a physical model can be established. The method consists of a measurement part and of a system part. The system part is derived from the physical model. Both parts are connected by the condition that measured and predicted deformations have to be the same. The condition equations are introduced as observations with very high weight. The physical parameters are then estimated in a least squares estimation.