Acoustic Testing of Composite Rebars Taking into Account Reinforcement Ratio

• Published in: Russian journal of nondestructive testing 2022-10, Vol.58 (10), p.891-902
• Main Author: Strizhak, V. A.
• Format: Article
• Language: English
• Subjects: Acoustic Methods; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composite materials; Defects; Fiberglass; Inhomogeneity; Materials Science; Nomograms; Rebar; Reinforcement; Structural Materials; Waveguides
• ISSN: 1061-8309; 1608-3385
• DOI: 10.1134/S1061830922600836

The need for effective and productive technical means of testing composite materials produced in the form of extended elements (pipes, rods, etc.) requires the adaptation of waveguide testing methods to the features of composite materials. The waveguide method makes it possible to evaluate the rod quality without scanning and uses a sensor mounted at the endpoint of the test object. Detuning from the influence of acoustic contact on the result is achieved using a parameter defined as the ratio of the inhomogeneity echo signal to the amplitude of the signal reflected from the opposite end. The reinforcement ratio of the composite material has a significant impact on the results. For composite rebars it is fiberglass. A model is proposed that takes into account the influence of the rod reinforcement ratio on the testing results by rod waves. On the basis of the model, coefficients and nomograms are calculated that make it possible to take the reinforcement ratio of the rod and the length of a defect into account when deciding on its significance. The result of assessing the significance of defects identified in 5 batches of rebars from different manufacturers is presented. Defects that are significant and insignificant for the properties of composite rebars are indicated.