Ultrasonic Testing of Fiber Reinforced Polymer Composites- An Overview (original) (raw)
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IJERT-Ultrasonic Testing of Fiber Reinforced Polymer Composites- An Overview
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/ultrasonic-testing-of-fiber-reinforced-polymer-composites-an-overview https://www.ijert.org/research/ultrasonic-testing-of-fiber-reinforced-polymer-composites-an-overview-IJERTV3IS060688.pdf Fiber reinforced composites are susceptible to fabrication defects, impact damage, moisture absorption, variability in material properties. It is often required to produce evidence through NDT methods to establish integrity of structures, repeatability of manufacturing process to ensure design stipulated strength, stiffness, thickness variation and material homogeneity. Usually a combination of complementary NDT is used for this. Conventional method of NDT, namely-Ultrasonic has been successfully applied to test, evaluate and certify composites.
Ultrasonic Non-Destructive Testing of Fibre Reinforced Composites
This thesis focuses on the application of high frequency ultrasound as a tool for performing non-destructive testing for pultruded fibre reinforced composite (FRC) rods. These composite rods are popular in the manufacturing, construction and electrical industries due to their chemical, electrical and strength properties. Such FRCs are manufactured on automated production lines that operate day and night. Non-destructive testing techniques are desired to quickly and accurately detectmanufacturing flaws such as coating thickness irregularities and surface cracks. Layers and cracks can present as large changes in acoustic impedance and will strongly reflect ultrasonic waves. Combined with their low cost, east of use and absense of potentially harmful radiation, ultrasound has proven popular worldwide for Non-Destructive Testing. Finite Element Analysis (FEA) was employed to investigate the propagation of ultrasonic waves through layers of material to simulate a thickness measurement an...
DYNA
Laminated composites are widely used in applications when a high strength-to-weight ratio is required. Aeronautic, naval and automotive industries use these materials to reduce the weight of the vehicles and, consequently, fuel consumption. However, the fiber-reinforced laminated materials are anisotropic and the elastic properties can vary widely due to non-standardized manufacturing processes. The elastic characterization using mechanical tests is not easy, destructive and, in most cases, not all the elastic constants can be obtained. Therefore, alternative techniques are required to assure the quality of the mechanical parts and the evaluation of new materials. In this work, the implementation of the ultrasonic through-transmission technique and the characterization of some engineering materials is reported. Isotropic materials and laminated composites of carbon fiber and glass fiber in a polymer matrix were characterized by ultrasound and mechanical tests. An improved methodolog...
Ultrasonic Non-Destructive Testing of Composite Materials
1983
C) UNCLASSYFIED SB CURITY CL.SSIFICATION OF THIS PAGE (When De eEnhored)_ REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM 1. REPORT NUMBER 2. GOVT ACCESSION NO. 3. RECIPIENT'S CATALOG NUMBER AFBP.-TP.-8 3 as 0 1 50 , 4. TITLE (ad Subtitle) S. TYPE OF REPORT a PERIOD COVERED ULTRASONIC NON-DESTRUCTIVE TESTING OF FINAL COMPOSITE MATERIALS 1 Aug 78-28 Feb 82 6. PERFORMING O1G. REPORT NUMBER 7. AUTHOR(&) 8. CONTRACT OR GRANT NUMBER(s)
ULTRASONIC TESTING OF GLASS FIBER REINFORCED POLYPROPYLENE COMPOSITES
The purpose of this paper was to find relationship between the degree of strength degradation caused by fatigue and the changes of ultrasonic wave characteristics such as wave velocity and damping coefficient. Polypropylene-glass composites were subjected to oscillatory bending loadings with constant deflection. During fatigue procedure the force needed to achieve constant deflection was measured. During fatigue tests samples were subjected to ultrasonic tests. Additionally before fatigue test and after 300000, 850 000 and 1 900 000 cycles parts of samples were subjected to destructive bending test. A good correlation between velocity of ultrasonic wave propagation and the degree of strength degradation of pp-glass composites caused by fatigue was found. Ultrasounds can be applied as effective tool to assessment of fatigue degradation of polymer composites. Achieved results showed that research have to be continued. Fatigue with other loading conditions and for other composite materials is planned. The results of present research can be applied to elaboration of non-destructive method of measurement of the degree of fatigue degradation of polymer composites.
Advanced Ultrasonic Testing and post-processing for detection of sustainable composites
e-Journal of Nondestructive Testing, 2022
Carbon-fibre reinforced composites (CFRP) and glass-fibre reinforced composites (GFRP) has seen widespread usage in various industries, from aerospace to utilities. With the 'the green shift' and the sustainability movement gaining momentum, there is an increased pressure for sustainable / natural materials to be used. Natural materials such as flax fibre can be used as a substitute for glass fibers. With the expectation that these composites will see increased usage, there is a need to develop inspection technologies. In this paper, single element immersion ultrasonic testing is used to inspect the flax fibre composites. The initial step involved inspection optimization to obtain ideal input parameters. The raw results had no clear detection of the seeded delamination (using Teflon sheets). An advanced post-processing technique used for fibre waviness detection in CFRP was applied to the data. This post-processing technique included frequency analysis, bandwidth analysis and amplitude analysis. The three types of data were separated from the raw data and visualized using a C-scan. Using this post-processing method, the seeded delamination could be detected. As a follow-up, more samples of various thicknesses and varying values of fibre waviness were fabricated to understand the limitation of inspection of flax fibers composites. This was achieved by having different thicknesses of Teflon sheets. The aim is to eventually have an inspection technique for a natural composite. This inspection technique and post-processing techniques has the potential to be applied onto the composite fabrication process, to aid in the manufacturing, optimization, and validation process.
Ultrasonic Testing of Glass Fiber Reinforced Composite with Processing Defects
2016
In this paper, the pulse-echo ultrasonic C-scan method was used for examination of various processing defects in a composite plate. The glass fibre reinforced epoxy matrix composite was prepared using vacuum infusion (VI). Several artificial defect were embedded into test plate varying in shape, volume and depth. During the specimen preparation with VI, air was introduced through small non-sealed spot in vacuum membrane. On the selected location, the PVC, aluminium foils and aluminium chips were inserted between layers. The immersion ultrasonic system with water couplant was used to study the defects in plate with 4D C-scan method using different frequencies and gate settings to find the optimum set of parameters to detect defects. The C-scan images show the detection and location of PVC foils and aluminium chips were successful. Also, the porosity can be clearly detected for individual layers. The thin, 0,04 mm aluminium foils were not detected with this method.
Eksploatacja i Niezawodnosc - Maintenance and Reliability
The paper presents selected issues in the field of exploitation research and the prediction capabilities of durability of composite laminates by ultrasonic methods used in the aerospace industry. Some research methods allow to set the quality parameters and operating in real aircraft structures. The study determined the relationship between the amplitude decrease of the ultrasonic wave and the level of porosity for hand lay-up manufactured glass / epoxy laminate using the method Through-Transmission of representative in C (TT C-Scan). In addition, showing the ability of amplitude attenuation imaging methods to detect and determine the extent of damage of high quality laminate and metal fiber composite after at low-dynamic velocity. It was specified real area an internal damage in FML laminates subjected to dynamic impact on low-energy, for which there was no visible damage in the outer layers. The study also determined the relationship between energy and the impact of dynamic surfac...
Integrated Ultrasonic Technique for Characterization of Composite Materials
Review of Progress in Quantitative Nondestructive Evaluation, 1993
The comprehensive non-destructive evaluation of modem composite materials requires the application of complementary techniques for the characterization of fabricated laminates. Current measurement methods, such as velocity and attenuation measurements of ultrasonic waves are, however, not integrated but require different ultrasonic and electronic system configurations. In this paper, an ultrasonic technique, previously developed by the authors for simultaneous wave speed and attenuation measurements [1], is applied to characterize composites. The amplitudes of tone-burst signals generated over a selected frequency range were measured to determine attenuation. For the determination of the wave velocity , a number of frequencies are selected at which a zero crossing of the tone-burst signal coincides with a zero crossing of a continuous reference sine wave. Various configurations of ultrasonic transducers for integrated measurements have also been investigated. A selected configuration of the ultrasonic and electronic system has been applied to characterize the porosity content in 200-ply unidirectional graphite/epoxy composite laminates. ULTRASONIC CONFIGURATION FOR MEASUREMENTS The attenuation and velocity of ultrasonic waves can be measured by using pulse-echo or through-transmission techniques. For materials with low signal loss, the information on absolute values of wave velocity and attenuation can be obtained by using multiple echoes from the bottom of the specimen. However, for materials with high porosity, one may not obtain even a single echo from the back face of the specimen due to signal loss. The use of non-contact transducers which is desirable for industrial purposes makes this problem even more difficult.