High-intensity Aerial Ultrasonic Waves Research Articles

Harmonic imaging of a defect in a flat plate using a guided wave generated by a high-intensity aerial ultrasonic wave

We propose the visualization of defects by means of guided waves generated simultaneously at multiple frequencies using the nonlinearity of a high-intensity ultrasonic wave. This report presents the use of the proposed method to visualize a slit in a thin metal plate. The results confirm that even though the multiple-frequency guided waves infiltrate the defect area in different directions, the defect can be visualized by imaging the wave propagation.

Detection of crack in a shallow layer of mortar by using a harmonic component of very high intensity aerial ultrasonic waves

We developed a noncontact, nondestructive method of imaging defects in solid objects with high-intensity aerial ultrasonic waves and optical equipment. The method detects defects in the imaged area by analyzing the velocity distribution on the surface of an object continuously irradiated with aerial ultrasonic waves. In this study, we attempted to detect a crack in a shallow layer of mortar. We used the nonlinearity of high-intensity sound waves and we imaged a rectangular defect imitating a crack (width: 1 mm) using harmonic components of the vibration velocity. Our method successfully imaged the rectangular defect, showing the possibility of its application to the detection of actual cracks.

Surface hardness monitoring of cement during curing by high-intensity aerial ultrasonic waves

We propose a method for monitoring the surface hardness of cement during curing by using high-intensity aerial ultrasonic waves and optical equipment. Our method estimates the progress of curing from the vibrations generated on the object surface by aerial ultrasonic wave irradiation. We monitored cement curing from a liquid state immediately after placement in real time and investigated a method for decreasing the dispersion of the measured values. As a result, we demonstrated that cement could be monitored from the liquid state to the solid state after placement. In addition, we confirmed that the effects of various external factors were avoided by using median measurement values.

Behavior of liquid in a thin type vessel irradiated with high-intensity aerial ultrasonic waves

A high-intensity aerial ultrasonic waves can remove liquid that has penetrated into the pores instantaneously. Further, tiny particles adhered to a solid surface is removed from the surface of object by radiation of the ultrasonic waves instantaneously. These techniques are implemented to a target by an action aerial ultrasonic waves directly. If these operations can be realized similarly even when the ultrasonic waves pass through the object, the field of application is expected to spread extremely. For example, if it is possible to exert a force to the liquid injected into a small container from the outside of the container by irradiating the aerial ultrasonic waves, various applications can be greatly expected. We have investigated the observations of liquid behavior when the high-intensity aerial ultrasonic waves were irradiated to the very small vessel filled with liquid. As a result, tiny bubbles were generated from the vicinity irradiated with the aerial ultrasonic waves, and the bubbles had a fierce tiny vibration. Further, in the observation of the liquid in the vessel by using ink, the ink is greatly diffused throughout the vessel and the behavior of the bubbles was confirmed to contribute to the diffusion of the ink extensively.

Non-contact heating of surface on the object using by high-intensity aerial ultrasonic waves

In the present study, the authors investigate a method of rising a temperature of an object’s surface for an instant without contact by using high-intensity aerial ultrasonic waves (frequency 20 to 50 kHz). In recent years, much attention has been directed at a thermal effect technology which utilizes ultrasonic energy such as HIFU and MRgFUS treatment. These technologies are realized for heating by using ultrasonic source which contact with a target. It is expected to realize the same heat effect by aerial ultrasonic waves, but a research of using ultrasonic waves to heat objects without contact has never been done. The authors propose a new method to use a very high-intensity aerial ultrasonic waves (intensity is about 25 kPa) which are generated by a point-converging acoustic source with a stripe-mode vibration plate and attempt to establish a technique. Recently, the authors reported that a temperature of silicone rubber material rise about 15°C after 1 second from the start of ultrasonic irradiation. With the realization of the technology, it is able to be a new underlying technology and is expected to be applied to a development of heating technique and non-destructive inspection.

Non-contact method for detecting crack in shallow layer of solid materials by using very high-intensity aerial ultrasonic wave and optical equipment

We have studied a noncontact and nondestructive method of imaging by using a high-intensity aerial ultrasonic waves and an optical equipment. This non-contact method detects a defect in solid materials by measuring a vibration velocity distribution on an object surface continuously irradiated by the aerial ultrasonic waves. In previous study, it was confirmed to image a relatively large peeling and defect in size by proposed method. Meanwhile, one of nondestructive testing target is a crack. It is difficult to vibrate the crack by this method has a lack of sound pressure of irradiating sound wave because the crack is very smaller than peeling. Therefore, in this study, we developed a new very high-power aerial ultrasonic sound source and attempted to detect the crack. In this report, we investigated to detect a crack in shallow layer of solid materials by this ultrasonic sound source. As a result, it is confirmed to image the crack around the shallow layer of object and the micro crack for extending to front surface of object by proposed method.

Transmission and irradiation of high-intensity aerial focused ultrasonic waves using pipe

In this study, we have developed a method that high-intensity aerial ultrasonic waves (sound pressure level: 180 dB) is transmitted to a far place and irradiate on optional and specified place without attenuation. To irradiate on the place that is optional and specified with high-intensity aerial ultrasonic waves, it is necessary to move the sound source. If any obstacle is placed between the specified place and the sound source, however, it will be difficult to irradiate to that place. In addition, there will also be a problem that ultrasonic waves attenuate during propagation in air. If these problems can be solved, it will be expected that more effective irradiation with ultrasonic waves may be realized and the range of applications may be widened. To solve the problem above, we proposed to use a rigid wall pipe whose inner diameter is similar to a wavelength to transmit the sound waves and attempted to simulate and experiment on the problem. In this report, we confirmed that the high-intensity aerial focused ultrasonic waves (frequency: 20 kHz) can be transmitted by using the pipe.

A non-contact detection of the internal defect in solid material by aerial ultrasonic beam

Measurement method using aerial sound waves and an optical equipment is utilized in a non-contact and non-destructive testing. Technique that we have been conventionally proposed, uses high-intensity aerial ultrasonic waves (20kHz). Specifically, a surface of an object is vibrated by high-intensity ultrasonic waves with a point focus. A vibration generated on the surface of the object is measured by laser Doppler vibration galvanometer. In general, the vibration of defect area is larger than that of defect-free area when the sound waves were irradiated to the object. Therefore, by performing the measurement over a target area, it is possible to image the defect area from the vibration distribution. However, this method needs a long time to measure the object with the defect. Therefore, we adopted a method of irradiating high-intensity ultrasonic to a wide range on the surface of the object using an aerial ultrasonic waves focused into a beam. In this report, we describe the details of the experimental results to detect defects in the object by using this technique.

強力空中超音波の発生方法とその応用技術

強力空中超音波の発生方法とその応用技術

Improved method of imaging defect in noncontact and nondestructive technique by high-intensity aerial burst ultrasonic wave and optical equipment

We propose a noncontact and nondestructive method of imaging by using high-intensity aerial ultrasonic waves and optical equipment. This method identifies defects in an imaged area by analysis of the velocity distribution of vibration on the surface of an object continuously irradiated by aerial ultrasonic waves. In a previous study, a related method was applied but could not exactly image the defect shape and size because the vibration mode at the target’s surface is generated by a continuous wave that depends on the boundary between the defective area and the defect-free area. By avoiding this problem, the proposed method allows exact imaging of the defect shape and size. In this report, we simulate results from the proposed underlying principle and conduct an experiment based on the proposed principle.

Basic Study of Nondestructive and Noncontact Measurement System for Estimating Fire Damage of Concrete by Using High-Intensity Aerial Ultrasonic Waves

Basic Study of Nondestructive and Noncontact Measurement System for Estimating Fire Damage of Concrete by Using High-Intensity Aerial Ultrasonic Waves

A Non-destructive Imaging Method for Detecting Defect in Mortal Sample by High-intensity Aerial Ultrasonic Wave

We have studied a method of non-contact ultrasonic inspection that uses high-intensity aerial ultrasonic waves and optical equipment. Specially, the object is excited in noncontact way using high-intensity aerial ultrasonic waves and the vibration velocity on the object surface is measured with a laser Doppler vibrometer (LDV). We analysis the vibration information on the surface of the object with the defect area and image the defect shape in materials. In this paper, it was examined to detect the defect in mortal by proposed method.

1P2-4 Non-contact Imaging for Micro Crack in Shallow Layer of Concrete Using Very High-intensity Aerial Ultrasonic Wave

1P2-4 Non-contact Imaging for Micro Crack in Shallow Layer of Concrete Using Very High-intensity Aerial Ultrasonic Wave

3P4-3 Temperature rise of soft material surface by irradiation with high-intensity aerial ultrasonic waves

3P4-3 Temperature rise of soft material surface by irradiation with high-intensity aerial ultrasonic waves

Transducer of high-intensity aerial ultrasonic wave and applied technology

Transducer of high-intensity aerial ultrasonic wave and applied technology

Basic study of an estimation method for fire damage within concrete sample using high-intensity ultrasonic waves and optical equipment

After a fire in a concrete building, concrete walls may need to be entirely or partially repaired depending on the size of the fire. If the building is to be repaired, it is necessary to determine the extent and cost of the work. To do so, a method is needed for determining the level of fire damage within concrete walls, particularly along the depth direction. In a previous work, we have investigated a noncontact, nondestructive method using high-intensity aerial ultrasonic waves and optical equipment to detect the level of fire damage on the concrete surface, and we have demonstrated the feasibility of obtaining such information. Yet it is also important to determine the level of fire damage within concrete sample, particularly along the depth direction, in order to determine the extent of necessary repairs. In this study, we examined a new noncontact, minimally destructive method for estimating the level of fire damage within concrete sample. The results show that the level of fire damage could be determined along the depth direction.

3P2-4 A Basic Study of Non-contact and Non-destructive Method by High-intensity Aerial Ultrasonic Wave : Comparing with Continuous Wave and Burst Wave(Poster Session)

3P2-4 A Basic Study of Non-contact and Non-destructive Method by High-intensity Aerial Ultrasonic Wave : Comparing with Continuous Wave and Burst Wave(Poster Session)

2P4-9 Removal of liquid in an elongated pore by very high-intensity aerial ultrasonic waves(Poster Session)

2P4-9 Removal of liquid in an elongated pore by very high-intensity aerial ultrasonic waves(Poster Session)

Examinations of Behavior of Liquid Irradiated with High-Intensity Aerial Ultrasonic Waves in a Long Pore

We experimentally verified the method of using the radiation force of high-intensity aerial ultrasonic waves at a frequency of 20 kHz to remove a liquid that entered a long pore. It was found that, on the wall surface of a cavity formed in the pore after the liquid had been removed by irradiating with ultrasonic waves, a small number of residual liquid drops linearly accumulated at multiple positions along the internal circumference of the cavity wall. The positions irregularly changed as the removal progressed. It can be considered that this phenomenon was mainly caused by the acoustic radiation force produced by nonlinear aerial ultrasonic waves. To explain this phenomenon, we observed in detail the behavior of the liquid; in addition, we performed a simulation of the acoustic radiation force produced by nonlinear aerial ultrasonic waves in a long pore, and compared the results of the simulation with the observed behavior of the liquid.

Basic examination of noncontact inspection in solid material by using high-intensity aerial ultrasonic waves and optical equipment

Recently, developments have improved methods employing aerial ultrasonic waves for contactless inspection of internal defects in materials such as metals, pipe walls, and fiber-reinforced plastics. Specially, this method is noncontact way differ from conventional ultrasonic inspection that is necessary to contact probe to object. We have developed a new method of aerial ultrasonic inspection that uses high-intensity aerial ultrasonic waves and optical equipments. That is, the object is excited in noncontact way using high-intensity aerial ultrasonic waves and the vibration velocity on the object surface is measured with a laser Doppler galvanometer at same time. We analysis the vibration information and detect defect in materials. We also developed a point-converging acoustic source with a stripe-mode vibration plate to generate the high-intensity aerial ultrasonic waves, an essential component of the method. While the sound source operates at a single resonance frequency, the generated ultrasonic wave has nonlinear acoustic characteristics and generates nonlinear higher harmonics at the focal point because the sound intensity increases by converging a sound wave. Under nonlinear ultrasonic irradiation, the object vibrates at the fundamental frequency and harmonic frequencies corresponding to the ultrasonic waves. Therefore, we also attempted to detect defect in materials for analyzing nonlinear vibration.