Phased Array Ultrasonic Technique Parametric Evaluation for Composite Materials

2014 ◽  
Author(s):  
Hossein Taheri ◽  
Katrina M. Ladd ◽  
Fereidoon Delfanian ◽  
Jikai Du
Keyword(s):  
Composite Materials ◽  
Phased Array ◽  
Composite Plates ◽  
Single Element ◽  
Bulk Wave ◽  
Plate Wave ◽  
High Attenuation ◽  
Array Transducer ◽  
General Improvement ◽  
Aluminum Plates

A series of ultrasonic elements arranged in a phased array transducer can provide the capability to activate each element separately but in a programmed sequence. This will help the acoustic signal to be generated at desired focusing distances and anticipated angles for specific materials and structures. In case of composite material inspection, this characteristic of the phased array method can improve the undesirable effects of the high attenuation and anisotropic structure of composite materials on response signals. In this study different phased array probes and wedges which are commercially available were evaluated for their response signals’ characteristics. First, the capability and resolution of bulk wave generation were studied for each set of probe and wedge, and the response signals were compared to that of the conventional single element ultrasonic transducers for different thicknesses composite plates. Then the resolution of the response signals and their sensitivity to defect size were evaluated and compared to the single element transducers as well. Next, each phased array probe and wedge set was used to generate plate waves in aluminum plates based on plate wave propagation theory, probe and wedge physical properties and the definition of delay law. Results show a general improvement in response signals’ strength and resolution for phased array method in comparison to the single element transducers. Also some plate wave modes could be generated with optimized signal generation parameters in phased array system.

scholarly journals Ultrasound Phased Array for High Acoustic Attenuation Thick Composite Materials

2015 ◽  
Author(s):  
Jikai Du ◽  
Ali Rajhi
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Composite Structures ◽  
Phased Array ◽  
Fiber Direction ◽  
Single Element ◽  
Acoustic Attenuation ◽  
Ultrasound Beam ◽  
High Attenuation ◽  
Beam Focusing

Composite materials and structures are increasingly being applied in aerospace, marine, and wind power industries, as well as in commercial products. One main reason for the scientific interest in composite materials is their tailorable mechanical properties. However, because of the fiber-direction-dependent nature of its physical and mechanical properties, composite material’s property and failure behaviors are usually complex, typically involving various mechanisms depending on applications. Nondestructive testing plays a key role during composite fabrication and maintenance in service. Among the variety of nondestructive techniques available, ultrasound phased array technique has emerged as a promising new approach. Unlike a conventional ultrasound single element transducer, an ultrasound phased array sensor can control and focus acoustic energy to the desired directions and locations. This heightened flexibility and sensitivity is essential given complex shape of modern composite structures. Despite such promise, understanding and application of ultrasound phased array technique is limited due to the anisotropic nature of composite materials, as well as its high acoustic attenuation. Attenuation and velocity dispersion are the two major challenges to the ultrasound evaluation of composite structures; these two factors complicate the control of phased array ultrasound propagation both theoretically and experimentally. This is especially true for thick high attenuation carbon fiber or glass fiber composite materials that have been widely applied in aerospace and wind turbine industries. In our study, ultrasound phased array technique was applied to increase the acoustic penetration power in high acoustic attenuation composite materials. First, ultrasound phased array signal in isotropic materials was studied to calibrate the probe parameters. Then for composite materials, the dependence of ultrasound field on the number of active elements, steering angles, beam focusing laws and on the characteristics of materials was analyzed and optimized through theoretical simulations and experimental evaluations. Results showed that the steering angles and the parameters of beam focusing laws might change the ultrasound beam intensity and uniformity, which had a significant influence on the sensitivity and resolution of the technique; the anisotropic properties of composite materials could distort the ultrasound beam, which made the calibration a necessary and important procedure during practical inspections. The influence of ultrasound frequency and beam angle were also quantitatively evaluated. The proposed research has the potential to apply ultrasound phased array technique to the detection of defects in composite materials and the evaluation of composite structural health. The study of the interaction between ultrasound and composite structures will open the window for the successful application of ultrasound phased array technique.

scholarly journals Nondestructive Ultrasonic Inspection of Composite Materials: A Comparative Advantage of Phased Array Ultrasonic

2019 ◽  
Vol 9 (8) ◽  
pp. 1628 ◽  
Author(s):  
Hossein Taheri ◽  
Ahmed Arabi Hassen
Keyword(s):  
Composite Materials ◽  
Guided Waves ◽  
Phased Array ◽  
Ultrasonic Inspection ◽  
Flaw Detection ◽  
Weight Ratio ◽  
Guided Wave ◽  
Single Element ◽  
High Attenuation ◽  
Ultrasonic Ndt

Carbon- and glass fiber-reinforced polymer (CFRP and GFRP) composite materials have been used in many industries such as aerospace and automobile because of their outstanding strength-to-weight ratio and corrosion resistance. The quality of these materials is important for safe operation. Nondestructive testing (NDT) techniques are an effective way to inspect these composites. While ultrasonic NDT has previously been used for inspection of composites, conventional ultrasonic NDT, using single element transducers, has limitations such as high attenuation and low signal-to-noise ratio (SNR). Using phased array ultrasonic testing (PAUT) techniques, signals can be generated at desired distances and angles. These capabilities provide promising results for composites where the anisotropic structure makes signal evaluation challenging. Defect detection in composites based on bulk and guided waves are studied. The capability of the PAUT and its sensitivity to flaws were evaluated by comparing the signal characteristics to the conventional method. The results show that flaw sizes as small as 0.8 mm with penetration depth up to 25 mm can be detected using PAUT, and the result signals have better characteristics than the conventional ultrasonic technique. In addition, it has been shown that guided wave generated by PAUT also has outstanding capability of flaw detection in composite materials.

Acoustic Emission and Ultrasound Phased Array Technique for Composite Material Evaluation

2013 ◽  
Author(s):  
Hossein Taheri ◽  
Fereidoon Delfanian ◽  
Jikai Du
Keyword(s):  
Acoustic Emission ◽  
Composite Materials ◽  
Composite Structures ◽  
Phased Array ◽  
Failure Modes ◽  
Acoustic Energy ◽  
Single Element ◽  
Signal Velocity ◽  
Acoustic Evaluation ◽  
Conventional Ultrasound

The successful application of various acoustic evaluation techniques to composite materials and structures depends on the understanding of the acoustic wave propagation mechanisms. However, due to the anisotropic nature of composite materials, where the acoustic signal velocity and attenuation depend on its traveling direction, the correlation of the different material failure modes to the recorded acoustic signals, such as during of an acoustic emission (AE) inspection, is difficult to be defined. This issue becomes even more challenging for ultrasound phased array technique, where unlike a conventional ultrasound single element transducer, an ultrasound phased array of sensors will generate and receive acoustic energy at various desired directions and locations. Such heightened flexibility and sensitivity is essential for the complex shape of modern composite structures. In this paper, the influence of fiber orientation on AE signal was first studied. AE parameters such as counts, duration, energy, rise time and amplitude for aluminum and composite plate were analyzed in MS-Excel and results were compared to AE software. Acoustic velocities along various fiber directions were also theoretically studied and experimentally measured. Then ultrasound phased array technique and related parameters such as ultrasound beam angle and focusing, frequency and material attenuation factors were quantitatively analyzed, and the optimization and limitation of ultrasound phased array inspection procedure were summarized.

Catheter Ultrasound Phased-Array Transducers for Thermal Ablation: A Feasibility Study

2005 ◽  
Vol 27 (2) ◽  
pp. 89-100 ◽  
Author(s):  
Kenneth L. Gentry ◽  
Nasheer Sachedina ◽  
Stephen W. Smith
Keyword(s):  
Phased Array ◽  
Pulse Repetition Frequency ◽  
Heart Tissue ◽  
Single Element ◽  
Ultrasound Transducers ◽  
3D Scanner ◽  
Array Transducer ◽  
Ultrasound Ablation ◽  
Design And Testing ◽  
Ultrasound Scanner

The feasibility of catheter single-element ultrasound transducers for cardiac ablation has been shown previously. We describe the design and testing of catheter-sized linear phased arrays transducers for ultrasound ablation. One array has 86 PZT-4 elements operating at 8 MHz and 5 MHz. The overall array size is 14.9 mm by 3.1 mm (10 Fr). The other array has 50 PZT-5 elements operating at 4 MHz and is 17 mm by 3.1 mm (10 Fr). In order to produce the intensity needed to create lesions in heart tissue, we modified a real-time, 3D scanner to produce 100 Vpp 256-cycle transmit pulses at a pulse repetition frequency of 14.1 kHz. This made it possible for the PZT-4 and PZT-5 transducers to produce ISPTA of 3.26 W/cm2 and 142 W/cm2, respectively. When driving the transducers at high duty factor, the transmit circuitry in the scanner was damaged. A mechanically-focused transducer with the same dimensions as the PZT-4 transducer was built. When transmitting continuously at 9 MHz, it produced an ISPTA of 29.3 W/cm2. This created a lesion 5 mm across and 5 mm deep in beef tissue while raising the focal temperature 23°C. Ablation is within the capabilities of a catheter phased array transducer integrated into a diagnostic ultrasound scanner.

scholarly journals Development of Low-Frequency Phased Array for Imaging Defects in Concrete Structures

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7012
Author(s):  
Yoshikazu Ohara ◽  
Kosuke Kikuchi ◽  
Toshihiro Tsuji ◽  
Tsuyoshi Mihara
Keyword(s):  
Lead Zirconate Titanate ◽  
Phased Array ◽  
Concrete Structures ◽  
Low Frequency ◽  
Concrete Specimen ◽  
Ultrasonic Waves ◽  
Center Frequency ◽  
Single Element ◽  
Array Transducer ◽  
Crack Type

The nondestructive inspection of concrete structures is indispensable for ensuring the safety and reliability of aging infrastructures. Ultrasonic waves having a frequency of tens of kHz are frequently used to reduce the scattering attenuation due to coarse aggregates. Such low frequencies enable the measurement of the thickness of concrete structures and detection of layer-type defects, such as delamination, whereas it causes a lack of sensitivity to crack-type defects. In this paper, to realize the ultrasonic phased array (PA) imaging of crack-type defects, we fabricated a low-frequency (LF) array transducer with a center frequency of hundreds of kHz. To avoid the crosstalk between piezoelectric elements and dampen the vibration of each element, we adopted soft lead zirconate titanate (soft PZT) with a low mechanical quality factor. Subsequently, we optimized the geometry of each piezoelectric element using a finite element method to generate a short pulse. After validating the design in a fundamental experiment using a single-element transducer, we fabricated a 32-element array transducer with a center frequency of 350 kHz. To show the imaging capability of the LF array transducer, we applied it to a concrete specimen with a delamination. As a result, the PA with the LF array transducer clearly visualized the delamination, which could not be visualized using the PA with a 2.5 MHz array transducer. Furthermore, we applied it to a more challenging defect, a slit, which is sometimes used to simulate crack-type defects. As a result, the PA with the LF array transducer clearly visualized a slit of 1 mm width and 40 mm height in a concrete specimen. Thus, we demonstrated the usefulness of the LF array transducer for inspecting crack-type defects.

scholarly journals Introduction to Macroscopic Optimal Design in the Mechanics of Composite Materials and Structures

2021 ◽  
Vol 5 (2) ◽  
pp. 36
Author(s):  
Aleksander Muc
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Constitutive Relations ◽  
A Priori ◽  
Chemical Properties ◽  
Composite Plates ◽  
Failure Criteria ◽  
Lagrange Equations ◽  
Homogenization Methods ◽  
Mechanics Of Composite Materials

The main goal of building composite materials and structures is to provide appropriate a priori controlled physico-chemical properties. For this purpose, a strengthening is introduced that can bear loads higher than those borne by isotropic materials, improve creep resistance, etc. Composite materials can be designed in a different fashion to meet specific properties requirements.Nevertheless, it is necessary to be careful about the orientation, placement and sizes of different types of reinforcement. These issues should be solved by optimization, which, however, requires the construction of appropriate models. In the present paper we intend to discuss formulations of kinematic and constitutive relations and the possible application of homogenization methods. Then, 2D relations for multilayered composite plates and cylindrical shells are derived with the use of the Euler–Lagrange equations, through the application of the symbolic package Mathematica. The introduced form of the First-Ply-Failure criteria demonstrates the non-uniqueness in solutions and complications in searching for the global macroscopic optimal solutions. The information presented to readers is enriched by adding selected review papers, surveys and monographs in the area of composite structures.

scholarly journals Acousto-Optic Cells with Phased-Array Transducers and Their Application in Systems of Optical Information Processing

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 451
Author(s):  
Vladimir Balakshy ◽  
Maxim Kupreychik ◽  
Sergey Mantsevich ◽  
Vladimir Molchanov
Keyword(s):  
Phased Array ◽  
Power Conversion ◽  
Experimental Studies ◽  
Acoustic Power ◽  
Acoustic Mode ◽  
Bragg Angle ◽  
Excitation Band ◽  
Acousto Optic Interaction ◽  
Array Transducer ◽  
New Type

This paper presents the results of theoretical and experimental studies of anisotropic acousto-optic interaction in a spatially periodical acoustic field created by a phased-array transducer with antiphase excitation of adjacent sections. In this case, contrary to the nonsectioned transducer, light diffraction is absent when the optical beam falls on the phased-array cell at the Bragg angle. However, the diffraction takes place at some other angles (called “optimal” here), which are situated on the opposite sides to the Bragg angle. Our calculations show that the diffraction efficiency can reach 100% at these optimal angles in spite of a noticeable acousto-optic phase mismatch. This kind of acousto-optic interaction possesses a number of interesting regularities which can be useful for designing acousto-optic devices of a new type. Our experiments were performed with a paratellurite (TeO2) cell in which a shear acoustic mode was excited at a 9∘ angle to the crystal plane (001). The piezoelectric transducer had to nine antiphase sections. The efficiency of electric to acoustic power conversion was 99% at the maximum frequency response, and the ultrasound excitation band extended from 70 to 160 MHz. The experiments have confirmed basic results of the theoretical analysis.

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