Crystal Instruments EDM Modal Hammer Impact Testing

Hammer Impact Testing is the EDM Modal module for hammer-based experimental modal testing, designed for single-operator use. Its graphical interface follows an intuitive step-by-step process, letting a user move easily through setup and testing. The workflow is built to help users define acquisition parameters quickly so more time can be spent on analysis. Trigger behavior is defined through Trigger Setup, and a Trigger-Preview window controls the trigger level and pre-trigger delay. For users who want to review each acquired frame, the Manual-Arm trigger mode displays the acquired signal for acceptance or rejection; Auto-Arm mode auto-accepts measurements and automatically re-arms the trigger to speed up the test.

The module also implements Driving Point Selection, which helps users decide where to place the fixed excitation or response reference. Several candidate driving points are surveyed and their FRFs measured, so the best available DOF can be chosen; EDM simplifies the data management for this important pre-test survey. During measurement, the status of all DOFs is shown in a table window that updates as the test progresses. The Trigger Preview window is optimized for viewing, with a resizable window and adjustable font size that grows as the window is enlarged, so users far from the display can still take measurements.

A common problem in hammer testing is the double hit. The module can automatically detect a double hit and let the user reject it automatically or manually. Hammer impact testing integrates seamlessly with the necessary post-test modal analysis inside EDM. Frequency response estimation supports H1, H2, H3 and Hv, and the software lists every DOF as acquired, in progress or not acquired, covering both simple and complex hammer modal tests.