Identification of rubber isolator dynamics: substructure frequency response functions for identification and cross validation

The dataset contains numerical and experimental frequency response function (FRF) data of substructures for rubber isolator identification. In both cases, two cross structures (C1 and C2) are mounted on either side of the rubber isolator, facilitating substructure excitation and response measurement in all directions, allowing one to perform the virtual point transformation (VPT) to obtain a twelve-degree-of-freedom (DoF) joint model representing the rubber isolator. Apart from FRFs of C1, C2, and C1_J_C2 substructures, FRFs of substructures A, B, and A_J_B are also provided, where A and B are connected by two identical rubber isolators. This allows one to cross-validate the identified joint model.

The numerical FRF data is obtained by forming finite element method (FEM) models of substructures C1, C2, A, J (rubber isolator), and B, where aluminum material properties are assigned to C1, C2, A, and B, while the isolator (J) material properties resemble a rubber-like material. Mode superposition is used to synthesize the numerical FRFs.

The experimental FRFs are obtained via impact excitation of substructures C1, C2, A, B, and assemblies C1_J_C2 and A_J_B, where A and B are made of aluminum, while the isolator (J) between C1 and C2 (and also between A and B) is made of rubber. Substructure excitation is performed using a modal impact hammer, while the response is measured using accelerometers. The H1 FRF estimator is used to estimate the FRFs of all substructures.

All FRFs are expressed in accelerance form. FRFs of a single substructure are stacked into an admittance matrix of shape (N_f, N_o, N_i), where N_f is the number of frequency lines, N_o is the number of response (output) degrees of freedom (DoFs), and N_i is the number of excitation (input) DoFs. The numerical FRF data, as well as response and excitation DoF location and orientation data are included in the file "numerical.h5", while the experimental data is included in the file "experimental.h5". Details regarding the organization of the files are provided in README.md.

3D models of substructures C1, C2, C1_J_C2, A, B, and A_J_B are also provided as STL files in the same coordinate system as response and excitation locations. Units used for STL files are millimeters. However, response and excitation DoF locations are provided in meters. Names of STL files corresponding to numerical substructures end with _num, while the names of STL files corresponding to experimental substructures end with _exp. FRF units are m/s²/N.