Crystal Instruments EDM Modal Complete Modal Testing and Analysis Software Suite

EDM Modal is Crystal Instruments' complete software suite for Experimental Modal Analysis (EMA). Running natively on Windows, it handles real-time data management and processing between a PC and every Crystal Instruments hardware platform. The interface manages complex tests involving hundreds of measurement points and multiple excitations, while still letting simple tests run quickly. Correct acquisition depends on book-keeping the degrees of freedom (DOFs) of the structure: the Geometry Editor models all structure types across Cartesian, cylindrical and spherical coordinate systems, and uses the concept of components to build a complicated structure in parts and integrate them. Measurement points and their directions are defined in the Input Channel Setup window, and acquisition then steps through the points according to each point's DOF information.

FRF signals can be acquired by several methods depending on the excitation arrangement, most commonly measuring excitation together with the response in hammer-impact or modal-shaker testing; with a shaker the drive signal may be random or sine. When excitation is unavailable or hard to measure, response-only Operational Modal Analysis (OMA) uses ambient excitation or the machinery's operating state. Modal parameter identification is the heart of the suite: single-reference FRFs use the Least-Squares Complex Exponential (LSCE) method for poles (natural frequency and damping); multiple-reference MIMO data use the Poly-Reference Time Domain (PTD) method, with Modal Participation Factors isolating closely coupled modes; mode shapes are computed with the Poly-Reference Frequency Domain (PFD) method.

An animation tool depicts mode shapes as 3D animations with color contours and Free-Form Deformation for smoother displays, and the same geometry model renders Operational Deflection Shapes from measured time or spectral responses. Supported workflows include geometry creation/import/export/animation, ODS analysis, hammer-impact modal testing, single or multiple shaker testing, swept and stepped-sine SIMO/MIMO modal testing, operational modal testing and analysis, single-reference, poly-reference and Poly-X (p-LSCF) analysis, data review and reporting to Microsoft Word, with support for Spider systems of up to 512 input channels.