Evaluation of damage anisotropy induced in GFRP composite materials by an innovative ultrasonic experimental approach
Journal: Research on Engineering Structures and Materials (Vol.4, No. 1)Publication Date: 2018-02-25
Authors : Anna Castellano; Pilade Foti; Aguinaldo Fraddosio; Salvatore Marzano; Mario Daniele Piccioni;
Page : 35-47
Keywords : Ultrasonic immersion test; Wave propagation; Damage mechanics; Composite materials; Anisotropic damage;
Abstract
We present a theoretical and experimental approach for the characterization of the damage induced anisotropy superimposed to the constitutive anisotropy of fiber-reinforced composite materials. The theoretical model here employed has been developed in the framework of the Continuum Damage Mechanics theory and allows for determining a tensorial damage measure based on the change of the elastic moduli of the composite material. Moreover, the model is general since it is applicable independently of the fibers reinforcement nature, of the presence of cracks, interlaminar voids and delamination, of the geometry of this cracks, and from of failure mechanisms of the composite materials. We perform damage experiments by using an innovative goniometric device designed and built at our laboratory (Laboratorio “M. Salvati”), and aimed at the mechanical characterization of materials. In particular, by rotating the sample into a water tank, we measure the ultrasonic “natural” velocities of the undamaged composite material along suitable propagation directions. This allows us for classifying the degree of symmetry of the material and for determining the elastic constants, also in highly anisotropic materials. Then we measure the ultrasonic velocities of the artificially damaged composite and we determine again the elastic moduli. The comparison between the elastic moduli of the damaged and the undamaged composite allows us for the characterization of the above cited anisotropic tensorial damage measure.
Other Latest Articles
- On self-equilibrium state of V-expander tensegrity beam-like grids
- Experimental analysis of premixed and non-premixed methane flames by using a new combustion system
- OPTIMIZATION OF SECOND LAW BASED EXPONENTIAL MODEL TO ASSESS THE EXECUTION OF PV ARRAY
- ANALYSIS OF THE PROBLEM OF WORD FORMATION IN GERMAN LINGUISTICS
- THE ROLE OF MOTHER TONGUE IN THE PROCESS OF LITERARY TRANSLATION: HOW MUCH CAN IT HELP?
Last modified: 2018-03-29 04:51:11