Computing method for estimating strain and stress of steel beams using terrestrial laser scanning and FEM

Terrestrial laser scanning (TLS) is the technique able to acquire the dense three-dimensional (3D) coordinates effectively over entire surfaces of the objects using laser pulses. Recently, TLS is often used in various fields such as civil engineering or archeology for object modeling, volume survey of tunnel, geographic information system (GIS), and the purpose to conserve the detailed shapes of cultural heritages. However, though its applications are extended continually, an application for system identification and structural health monitoring is a beginning stage. To improve the quality of data for the model based on TLS coordinate information, the digital elevation model (DEM) constructing method is applied. In a practical point of view, since there is no need to place a strain or stress sensor to a structure to be monitored, this model could has many advantages such as no in situ instrumentation of sensors, no difficulties to reach structures or structural members, independence of natural light source and no wiring cost. For the verification of this model, experimental tests are performed with a continuous steel beam subjected to point loads.