ISI-SYS LOADING METHODS

LOADING METHODS

Flexible and Efficient: One sensor system for dynamic, thermal and vacuum loading.

Dynamic Loading

For the dynamic loading, the Piezoshaker excitation systems are designed by ISI-Sys. It consists of a Piezoshaker, amplifier and function generator.

Lamb waves are generated by the Piezoshaker, which is attached to the bottom of the specimen. The waves travel across the object surface and excite the five local subsurface defects on the top. The local defects vibrate differently, depending on their local mechanical properties (stiffness). Only very little power of the piezoshaker is required when the excitation frequency is close to the local defect resonance frequency. This principle is used in non-destructive testing, for example, especially to locate delaminations in sandwich structures.

The Piezoshaker can be attached by vacuum to the object surface. The HVDA‑0–180 AMPLIFIER is especially designed for isi-sys Piezoshakers and mobile applications, where high power at low weight and compact size is a big advantage for mobility and flexible handling. High frequencies up to 100 kHz and more, as well as large forces and acceleration, have been generated in combination with the different isi-sys Piezoshaker modules.

Thermal Loading

isi-sys offers timed thermal loading modules to heat the objects of measurement.

An automated, precise control of heat loading and a corresponding timed shearographic measurement is required to achieve a reproducible test procedure for non-destructive testing experiments and automated systems.

Any conventional halogen flood lights with 220V can be connected. isi-sys recommends some flood lights used for professional photography. Thus, they can be mounted on a standard light stand of e. g. Manfrotto, etc. and easily directed to the area of interest independent of the sensor head. Also, these lights offer some choices of reflector combinations.

The start and duration of the heat loading and the measurements can be set per computer-controlled timer, which permits reproducible sequences of the test process.