Comparison of vibration measurements and finite element model results in vibration fixtures

Every product is exposed to environmental conditions that may prevent it from operating in its environment and cause structural damage, these products, which are produced by verification by analysis, are verified by subjecting to a number of environmental conditions tests. In this study, a vibration test fixture has been designed to transmit vibration with minimal loss between the shaker and the product during vibration tests. The design was completed accordance to the appropriate limits for harmonic and random vibration in the military standard MIL-HDBK-2164A with using the ANSYS program. The designed vibration test fixture is manufactured using Al 6061 series and St52 steel materials. Experimental data were obtained with accelerometers on the vibration test fixture, which was manufactured and connected to the vertical axis assembly of the shaker. Analysis data and experimental data were compared. It has been observed that tetrahedral element type gives better results than hexahedron element type in mesh structure. Considering the results of harmonic vibration analysis, the values obtained for the X and Y axes are within the tolerance range in accordance with the standard and the value of 0.489 obtained in the Z axis was considered appropriate because it was within the tolerance range specified in the standard at 2000 Hz. In addition, when the rates of GRMS values in random vibration analysis were examined, it was seen that these ratios were 1,043. It has been evaluated that the vibration test fixture will successfully transmit vibration-induced energy even though it cannot fully transmit the vibration profile in some frequency ranges in random vibration tests.