Assessment of structural health relies on measurements which can be related to global and local structural parameters.  The goal of the structural dynamics and monitoring laboratory is to provide laboratory testing facilities for investigating new methodologies, and for comparing them to currently accepted or existing techniques.

Scale Models

The laboratory includes several scale model structures, such as the truss bridge shown in Figure 2.1.  These models are useful for testing data acquisition equipment, and for validation studies of damage detection algorithms.

Figure 2.1 Truss bridge.

Computer Equipment and Software

The structural dynamics lab includes seven computer systems for general purpose computing, finite element analysis, and for dedicated signal processing.  The latter function is performed with a 533 MHz ALPHA workstation running Linux and Windows NT (figure 2.2).  The workstation is configured as the central data server for the laboratory.  Data can be archived on hard disks, or can be archived to high density tape cartridges.

Figure 2.2	Figure 2.3

Large scale finite element simulation of the mechanical and thermal response of structures is conducted on a Silicon Graphics workstation running ABAQUS software (figure 2.3).

Measurement Equipment

The dynamics laboratory includes standard test equipment, such as sampling oscilloscopes. Other equipment is available for the measurement of strain and temperature.

Figure 2.4	Figure 2.5

Computer automated testing and data acquisition is a feature of the laboratory.  Two computer systems are available.  These computer acquisition system are controlled by DASYLAB software, and support aggregate acquisition rates of 100 KHz.  Strain and temperature conditioning cards have been interfaced to these systems.  An 8-channel simultaneous sampling card with analog anti-aliasing filtering is in development for real-time modal parameter estimation.

Vibration Test Equipment

The dynamics laboratory includes a drop hammer for impulse testing of relatively large structures. Smaller dynamic testing is accomplished via a Vibration Test Systems VTS 40 with a random controller.

Figure 2.6	Figure 2.7