Preliminary Study on the Acoustic Emission Wave Velocity on Filament Wound Glass Fiber Reinforced Polymer Pipes and its Correspondence with the Winding Angle

Abstract

In this study, three types of filament wound glass fiber reinforced epoxy composite specimens were tested according to the ASTM standards to evaluate preliminary, the acoustic emission wave velocity. The pipe specimens had 300.0 mm of length, 50.5 mm of diameter and 3.5 mm of wall thickness. Ten points were marked over the imaginary central circle on the pipe middle, from zero degree up to 90º with nine divisions of 10º each one and an additional point representing the crossing of plies. Next, there are positioned two collinear acoustic emission (AE) sensors along the length, positioned at 35 mm from middle, axially. After the specimen preparation, took place theHSU-NIELSENor pencil lead break (PLB) tests to analyze the signal wave time for both sensors, by means of the 0.3mm – 2H graphite lead brake. The results were compared to considering the angular variation and the velocity for each winding angle. It was evident that the procedure above can determine with good precision the variations occurred on the acoustic emission velocity on filament wound composite pipes, regarding the three angular variations compared. This study was the parameter of control to proceed with the acousticemission evaluation over tensile tests in further studies to predict the fatigue and the damage propagation on this typology of laminates.

Dynamic Elastic Modulus Variability in Anisotropic and Isotropic Materials: Comparison by Acoustic Emission

“…Table 4 shows the results of the elastic dynamic moduli in the various directions of the laminate and the comparison with elastic moduli of steel, from the resulting velocities of the PLB [7] test, after the application of intermediate results on Equations 4 to 12 above, for each typology of composite pipe, and for the SAE 1020 pipe. Table 4 shows the great variation of modules for the FW SPs, according to the wave incidence regarding the C P (values typed in bold), in which the signal wave is parallel to the last ply of roving bands.…”

“…Thus, for each design of great complexity is necessary to evaluate the typology of the composite that will be used. In contrast, structural members and components need their evaluation during their serviceable life, because of critical conditions of use environmental, seismic, or fatigue, which could cause injuries in humans [1][2][3][4][5] The previous articles [6,7] showed the behavior of the acoustic signals over filament wound composite pipes, and how the position of the signal source or, in this case, the damage occurrence could be interfered with by the interlacing of opposites filaments of roving, regarding the lamination path. Three types of This paper presents the continuation of prior studies, which comprised the verification of the variation that occurred in the dynamic elastic modulus (E 11 ) regarding the three angular winding laminations described, in comparison with an isotropic material.…”

“…It is well known how the AE can find damage occurrences and crack propagation in composite materials [7][8][9][10][11][12][13], as so as the procedures to use the nondestructive technique [14][15][16] for evaluation of damage propagation, for numerous composites and plate structures [9,11,17,18]. However, the literature presents scarce works on industrialized lamination processes evaluation, where the layering presents unusual directions like FW, the pultrusion, sheet molding compound (SMC), or automated fiber placement (AFP), which use unidirectional or bidirectional fabrics, or prepreg [19].…”

Comparison between elastic properties of theoretical, computational method and experimental results for filament wound composite pipes

“…The calculation models most commonly used in the design of composite structures are classical laminate theory (CLT) and the rule of mixtures (RM), both of which have been discussed extensively in the literature [2][3][4][5][6][7][8][9].…”