Approbation оf the Method for Stiffness Parameters Identification of Spatial Structures on Experimental Stands

Abstract

Mathematically formalized technique for stiffness parameters identification of spatial structures has been tested on two physical experimental models, "Constructor" and "Etazherka". The specific feature of the stand "Constructor" is the sensitivity of natural frequencies and mode shapes of a significant spectrum part to the inflicted damage. The specific feature of the stand "Etazherka" is the indifference of a significant spectrum part to the inflicted damage. Identification of stiffness parameters and defects of various stand states is performed.

An algorithm for selecting priority minimization components is proposed. The algorithm provides correct identification of stiffness parameters under conditions of significant "contrast" change of a significant spectrum part. The algorithm also significantly increases the computational efficiency of the equivalent minimization problem. For a detailed study of resonance characteristics, the method of standing waves in the digitized version was used. The correct results of approbation of the technique for the stand "Constructor" were received. For the stand "Etazherka" the influence of errors and noise leads to localization errors by the height of the damaged "column". Damage localization errors can be overcome by improving the accuracy of mode shapes components or by investigating higher system frequencies and mode shapes. As a whole, results of approbation show that the technique is applicable for research of spatial structural schemes and can be demanded as a component of information, analytical and mathematical models of digital twins as a part of modern dynamic monitoring systems.