Ultrasonic Testing Device Research Articles

Modernization the system of periodic control for the concrete properties

Periodic control of concrete properties is based on the use of nondestructive methods. Periodic monitoring of the condition of structures often is performed using ultrasonic devices. The accuracy of determining the physical and mechanical characteristics (FMC) of concrete depends on a significant number of factors affect. This reduces the accuracy of the results by standard methods. Based on previous studies, the methodology for using ultrasonic non-destructive testing devices was improved. The research and verification of the improved methodology in a real building demonstrate the low complexity of the work and sufficient reliability of the results. Improvement of the algorithm for work and data processing will allow to offer a reliable methodology for determining the technical condition of the operated structures and for periodic monitoring the concrete properties. A methodology for periodic monitoring of concrete properties in structures has been developed. It is necessary to carry out.

Discontinuity Detection System in Marble: Analysis of the Time-Frequency Characteristics of Ultrasonic P-waves

Abstract This study attempted to determine both the presence and the appearance of the surface of a crack artificially created in a marble block without axial loading or compression by FFT analysis of ultrasonic longitudinal sound waves by scanning the surface. In such respect, the study differs from other studies in the literature. The aim of the study was to minimize marble waste by determining the most appropriate slab cut direction based on the orientation of the fracture or discontinuity within the marble block. During location-controlled scanning of the marble surface, mean longitudinal wave velocity, Young modulus, Poisson ratio and longitudinal wave velocity variation data were obtained using a V-Meter Mark IV™ ultrasonic test device. For each location, longitudinal ultrasonic velocity data was taken at 250 kHz sampling rate and 256 data points were created. Data from the computer environment were subsequently reorganized using the MATLAB software and FFT conversions for such velocity data were obtained for each location. Then, the peaks of the FFT transformation components were determined by using the “Findpeaks” function in MATLAB‘s signal processing toolbox. The number of peaks in the 50-60 kHz range was determined for each location. A single difference was determined between the peak numbers at the locations within the cracked and uncracked regions. By examining the FFT graphs, it was determined that such additional peak occurring in the cracked regions appeared as a second frequency component near the dominant frequency values. Points with secondary frequency were recorded as 1, while all other points were recorded as 0 in a new matrix. Such data matrices created for each sample were examined by visualization in the form of surface graphics. Using these graphics, the orientations of discontinuities within the marble block may be determined according to the scanning surface.

Kavitasyon İşleminin Denim Kumaşların Termal Konfor Özelliklerine Etkisi

The process, which is defined as ultrasonic treatment or cavitation, ensures that the dirt is removed from the surfaces without damaging the fabric surface. There are studies on the ultrasonic washing processes of denim fabrics in the literature, but there is no study on the effect of the cavitation process on the thermal comfort of denim fabrics. For this purpose, denim fabrics were treated at three different times, 15, 30, and 45 minutes, and at two different frequencies 8khz and 16khz in the ultrasonic homogenizer test device. It was observed that the applied cavitation process reduces the air permeability, thermal conductivity, and thermal absorptivity values. On the other hand, the cavitation process increased the water vapour permeability value by cleaning the materials such as dirt and oil on the surface. It can be concluded that the applied cavitation process provides comfort by enabling quick throwing of the sweat to the outer surface, provides less heat conduction from the fabric, and the denim fabric felt warmer after the cavitation process.

Shell folded footings using different angles and EPS cavity filling: experimental study

Shell folded footings have drawn the interest of researchers for decades as an alternative to typical flat isolated footings because folded footings can reduce the needed amount of reinforced concrete in addition to enhancing the overall geotechnical performance of the supporting soil medium. The main setback of utilizing such folded footings is the relatively complex geometry of the bottom cavity, which requires proper compaction of the soil used to fill that cavity. Current geosynthetic materials such as geofoam or expanded polystyrene (EPS) proved efficiency in many geotechnical applications, where EPS was adopted herein as a cavity-filling material for folded footings. EPS and footing concrete properties were determined using the ultrasonic test device, such as modulus of elasticity and damping coefficient. The main aim of this study was to experimentally assess the behavior of folded footings with and without EPS filling using seven fully instrumented footing models with folding angles ranging from 0° to 45°. Reinforcement was placed in the footing models and limited along the perimeter to act as a hidden ring beam. The models were load tested inside a sandbox to measure internal stresses induced in the soil and the overall settlement. Results showed a significant enhancement in the soil behavior after using EPS. Modification factors were developed for the standard bearing capacity and settlement equations to account for the folding angle and EPS filling effects.

The influence of skills in working with ultrasonic devices on the sustainable development of the quality of control of test results

This article deals with the problem of taking into account the level of proficiency of ultrasonic non-destructive testing devices by construction control specialists for the sustainable development of test quality. In the process of conducting input control operations of structural materials entering the construction site, there is a need for their detailed verification using non-destructive testing devices. At the same time, the results obtained with the help of portable ultrasound monitoring devices may differ from one specialist to another. This fact may call into question the regulatory organizations that accept and analyze the results of these tests. This study presents the results of ultrasonic testing of various building materials. The main feature of the study is that measurements are carried out by different people using a single calibrated ultrasound device. The introductory part of the article describes the formulation of this problem in the industry and the need to find solutions. The Methods section describes the applied methods and experimental conditions. In the discussion section, the question of the need for further more detailed studies of the problem of using non-destructive testing methods for the sustainable development of the quality of tests performed will be raised. As a result of the conducted research, a generalized analysis of the information received was carried out, conclusions and recommendations were formulated.

Design Theory and Experimental Research of Ultrasonic Fatigue Test

Ultrasonic fatigue testing is a key technology that is more efficient and energy saving compared to conventional fatigue testing. In order to investigate the behavior of metallic materials at ultra-high frequencies and to verify the validity of ultrasonic fatigue test results, this paper builds a test apparatus that can be used to conduct ultrasonic fatigue tests, and this paper proposes a complete procedure from theoretical analysis to the investigation of test laws for 20 kHz tensile and the compression test. Firstly, the initial sizes of the sample are calculated with an analytical method, then the three-dimensional model is simulated and optimized with finite element software, and the optimum result for the sample size is then obtained according to the sensitivity of the sample size to the effect of frequency. The next step is to analyze the influenced trend of the sample size, including L1, L2, L3, R1 and R2, on the resonant frequency and maximum stress of the sample. According to the optimized results, the sample was processed, and an ultrasonic fatigue test was carried out to ensure the sample fatigue fracture finally occurred. Finally, the S-N curve of the material was plotted based on the data recorded in the test and compared with the conventional fatigue life curve to verify the feasibility of the ultrasonic fatigue test device and test method. The fracture of the sample was observed using an optical microscope, and its macroscopic fracture morphology was analyzed. The fracture morphology of the sample can be divided into three typical zones: the fatigue crack source zone, the extension zone and the transient zone, where the fatigue cracks all originate from on the surface of the sample. The results demonstrate the validity of the ultrasonic fatigue test results and provide new ideas for the design and optimization of ultrasonic fatigue samples and shorter processing times, providing a reference for subsequent ultrasonic fatigue tests on typical materials.

Mechanical Properties and Damage Mechanism of Shale Ceramsite Concrete after High-Temperature Treatment

The high-temperature resistance of lightweight shale ceramsite concrete (LWSCC) is seriously underestimated because the effect of moisture is not considered. To investigate the mechanical properties and damage of LWSCC after a high-temperature treatment, strength tests, X-ray diffraction (XRD), and scanning electron microscopy (SEM) were carried out, and a nondestructive ultrasonic testing device was used to quantify the damage. The results show that the spalling characteristics of LWSCC at high temperatures were closely related to its water content. The axial compressive strength of LWSCC linearly decreased with increasing target temperature. LWSCC showed a greater resistance to high-temperature deterioration than NWC with the same mass loss ratio. LWSCC with a moisture content of 4.1% had a high probability of spalling at temperatures above 500°C. However, dry LWSCC had a low probability of spalling even when heated to 800°C. Water in shale ceramsite with a porous structure was identified as a critical factor in the high-temperature deterioration. After the temperature exceeded 200°C, the high-pressure steam in the ceramsite expanded the cracks. These findings provide a basis for designing LWSCC with high-temperature resistance and evaluating the safety of LWSCC buildings after fires.

Evaluation of a pressure vessel using failure analysis diagram based on phased array ultrasonic testing data

ABSTRACT A pressurized gas separator vessel was scanned to detect the possible discontinuities using a Phased Array Ultrasonic Testing (PAUT) device. Ultrasonic results from Hydrogen-Induced Cracks (HICs) at different depths were considered to represent the evaluation procedure. Final results were then generated for implementing Fitness-for-Service (FFS) procedure. After considering FFS procedures, it was found that some of the discontinuities are not acceptable due to their sizes or locations. Based on the simulated model results, including fracture analysis of cracks and generating Failure Analysis Diagrams (FAD), it can be inferred that the vessel is not acceptable to be in the current service operation condition and should be replaced.

Advanced Prediction Model for Pipe Wall Thinning Tendency by Flow Accelerated Corrosion at Junction Piping

Flow Accelerated Corrosion (FAC) is a pipe wall thinning phenomenon to be monitored and managed in the power plants with high priority. Its management has been conducted with conservative evaluation of thinning rate, and residual lifetime of piping based on wall thickness measurements. However, noticeable case of the wall thinning occurred in branch and junction piping (tee tube). There is a problem to manage the wall thickness beneath reinforcing plate of the tee tube, because measurement of this area is difficult to be conducted with ordinary ultrasonic testing devices due to the presence of the reinforcing plate. In this study, numerical analysis for the tee tube was conducted, and the wall thinning profile due to the FAC was evaluated by calculating the mass transfer coefficient. It was found that a localized wall thinning distribution occurs in the area where the reinforcing plate of the tee tube exists. And this tendency is affected by Reynolds number. In previous studies, a model was introduced to predict this trend, but in this study, the model was improved to take into account the effect of the Reynolds number.

Creep properties and resistivity-ultrasonic-AE responses of cemented gangue backfill column under high-stress area

To investigate the creep and instability properties of a cemented gangue backfill column under a high-stress area, the uniaxial compression creep tests were conducted by single-step and multi-step loading of prismatic samples made of cemented gangue backfill material (CGBM) under the high stress-strength ratio. The creep damage was monitored using an electrical resistivity device, ultrasonic testing device, and acoustic emission (AE) instrument. The results showed that the CGBM sample has a creep hardening property. The creep failure strength (CFS) is slightly larger than the uniaxial compressive strength (UCS), ranging in ratio from 108.9% to 116.5%. The instantaneous strain, creep strain, and creep rate increase with increasing stress-strength ratio in the single-step loading creep tests. The instantaneous strain and creep strain decrease first and then increase during the multi-step loading creep process. The axial creep strain of the CGBM column can be expressed by the viscoelastic-plastic creep model. Creep instability is caused by the accumulation of strain energy under multi-step loading and the continuous lateral expansion at the unconstrained middle position during the creep process. The creep stability of a CGBM column in a high-stress area can be monitored based on the variation of electrical resistivity, ultrasonic pulse velocity (UPV), and AE signals.

Analysis of Heat Island Effect in Coastal Cities Based on the Change of Surface Parameters

Zhou, Z.; Deng, Q.L., and Yang, G., 2020. Analysis of heat island effect in coastal cities based on the change of surface parameters. In: Bai, X. and Zhou, H. (eds.), Advances in Water Resources, Environmental Protection, and Sustainable Development. Journal of Coastal Research, Special Issue No. 115, pp. 289-291. Coconut Creek (Florida), ISSN 0749-0208.In order to analyze the influence of urban surface parameters on the heat island effect in coastal cities, it is very important to establish scientific measurement methods and instruments. On this basis, the surface thermal effect measuring device is studied. Combined with the main problems existing in the study of ocean thermal parameters, the overall design scheme of the system is given, including the structural design of the measurement section and the functional design of the system. How to further improve the accuracy of Ocean Climate Measurement prototype is studied. An ultrasonic transducer testing device is designed. In addition, aiming at the disadvantage that the traditional flow algorithm is easy to be affected by the uneven distribution of flow velocity and temperature, a flow segmented interpolation algorithm is studied. Finally, the verification method and test results of the prototype calorimeter are given. The results show that the flow measurement error and temperature measurement error of the calorimeter are within the allowable range. It can meet the design requirements of national secondary meters. At the same time, it has important guiding significance and technical reference value for the follow-up study of the ocean ultrasonic calorimeter.

Düşük Dayanımlı Betonların Elastisite Modülünün Bulunması

This study aims to experimentally determine the elasticity modulus of low strength concrete and propose new elasticity modulus equations. Studies on elasticity modulus have been generally carried out for normal and high strength concrete samples. The elasticity modulus can be determined as static and dynamic elasticity modulus. 64 concrete test samples were prepared in this study. 38 samples were placed on the stress-strain frame and subjected to the compression test to determine static elasticity modulus. 40%, 45% and 50% of the characteristic concrete compressive strengths were used as a second point on the stress-strain curve to determine the static elasticity modulus of low strength concrete according to TS 500, ACI 318-11 and CEB 2004, respectively. Static elasticity modulus values were compared with three code equations and it was observed that three codes yield higher elasticity modulus values for low strength concrete. Dynamic elasticity modules of 26 concrete samples were determined using an ultrasonic test device. Dynamic elasticity modulus values were compared with Hermit function. It was observed that Hermit function also gives higher elasticity modulus values. Therefore, new equations for static and dynamic elasticity modulus of low strength concrete were proposed based on the experiment results using regression analysis.

In situ synchrotron ultrasonic fatigue testing device for 3D characterisation of internal crack initiation and growth

AbstractThis work presents a new ultrasonic fatigue testing device for studying the initiation and propagation mechanisms of internal microstructurally short fatigue cracks using in situ synchrotron tomography. Its principle is described as well as the method used for automatically detecting crack initiation and its subsequent growth. To promote internal crack initiation, specimens containing internal casting defects were tested between the high cycle and very high cycle fatigue regimes (107‐109cycles). Preliminary results show the ability of this new device to initiate an internal microstructurally short crack in a reasonable testing time and monitor its growth.

Convolution of Barker and Golay Codes for Low Voltage Ultrasonic Testing

Ultrasonic Testing (UT) is one of the most important technologies in Non-Detective Testing (NDT) methods. Recently, Barker code and Golay code pairs as coded excitation signals have been applied in ultrasound imaging system with improved quality. However, the signal-to-noise ratio (SNR) of existing UT system based on Barker code or Golay code can be influenced under high high attenuation materials or noisy conditions. In this paper, we apply the convolution of Barker and Golay codes as coded excitation signals for low voltage UT devices that combines the advantages of Barker code and Golay code together. There is no need to change the hardware of UT system in this method. The proposed method has been analyzed theoretically and then in extensive simulations. The experimental results demonstrated that the main lobe level of the code produced by convolution of Barker code and Golay code pairs is much higher than the simple pulse and the main lobe of the combined code is higher than the traditional Barker code, sidelobe is the same as the baker code that constitutes this combined code. So the peak sidelobe level (PSL) of the combined code is lower than the traditional Barker code. Equipped with this, UT devices can be applied in low voltage situations.

The evolution of structural and elastic properties of a Zr-based metallic glass upon annealing below glass transition temperature

Bulk metallic glasses are often used well below their glass transition temperatures, Tg, because of their change in the physical properties of the material through its glass transition, which is not considered a phase transition; rather it is a phenomenon extending over a range of temperature and is defined by a viscosity threshold of 101 2 Pa ⋅ s. In this work, a Zr-based metallic glass upon annealing below glass transition temperature (Tg–30 K) was quasi-in-situ investigated. The structural and elastic properties were observed carefully by utilizing an in-house designed density testing device and an ultrasonic testing device. We found out that the density, the shear velocity, the longitudinal wave velocity, and the elastic modulus increased through annealing at 719 K for 300, 900 and 1500 s. A possible explanation was presented based on the free volume theory and it was found that the relaxation kinetics in this study obeyed the Kohlraush–Williams–Watts (KWW) relaxation function with [Formula: see text] = 0.420 [Formula: see text] 1 implying that the relaxation mechanisms were multiple ones.

Simulation and Experimental Study on the Discontinuous Dynamic Impact on Unidirectional Confined Coal‐Rock Damage

The deformation and the damage characteristics of coal and rock under different restraint static load and different impact velocity were studied with the FEM software LS‐DYNA. Based on this, the influence of impact load on the damage of coal rock under one‐dimensional constraint condition was studied by using the self‐developed constrained pendulum impact dynamic loading test device and ultrasonic testing device. The results show that the deformation of coal and rock increases with the increase of impact velocity and decreases firstly and then remains constant with the increase of constraint static load; when the constraint static load exceeds the compression strength, the displacement increases rapidly and the coal collapses at a strike; the damage quantity of coal and rock has a cumulative effect, and the damage quantity increases with the increase of impact number; when the constraint static load is identical, the increase of impulse contributes to microcrack propagation, and the damage quantity of coal and rock accelerates with the increase of single impact impulse; when the impulse is identical, the constraint static load restrains the microcrack propagation, and the damage quantity of coal and rock decelerates with the increase of constraint static load; the complete damage quantity range of coal and rock is 0.65∼0.75. In order to fully destroy the coal and rock, if the single horizontal impulse is greater, the number of shocks needed is less; if the constrained static load is greater, the more impact times are needed.

Influence of particle and short-fibre reinforcement on the very high cycle fatigue behaviour of aluminium matrix composites

The fatigue behaviour of aluminium matrix composites (Al-MMCs) reinforced by alumina particles (15 vol% Al2O3) or short-fibres (20 vol% Saffil), respectively, was investigated in the very high cycle fatigue (VHCF) regime at stress amplitudes ≤140 MPa to reach fatigue lives of up to 1010 cycles using an ultrasonic fatigue testing device. Fatigue tests were complemented by in situ thermographic measurements to record the temperature of the whole specimen and to find “hot spots” indicating changes in microstructure and, therefore, the initiation or growth of cracks. Results obtained in the VHCF-region fit well with results obtained in LCF/HCF-region. A significant influence of test frequency was not found. Surprisingly, the reinforced Al-MMCs are capable to bear up to 109 cycles, although damage starts early during cyclic loading. In addition, although in the LCF/HCF regime the fatigue life and fatigue strength of the short-fibre reinforced Al-MMCs are significantly smaller compared to particle reinforced and unreinforced material, no significant differences to the particle-reinforced and unreinforced Al-MMC were observed at stresses below 140 MPa. Moreover, at stresses below 80 MPa not fatigue failure occurred at all up to 1010 cycles.

Experimental Study of Damage Development in Salt Rock under Uniaxial Stress Using Ultrasonic Velocity and Acoustic Emissions

Ultrasonic waves and acoustic emissions (AE) are important technologies to reveal rock damage. However, few studies have simultaneously monitored both types of data in the same experiment because of limitations on the experimental apparatus. In this study, an integrated ultrasonic wave and AE testing device was developed to investigate the deformation characteristics and damage development of salt rock. Fracture experiments under uniaxial compression were carried out on three samples from the Jintan Salt Mine, Jiangsu Province, China. The deformation process can be divided into five stages. In the compression fissure and linear deformation stages, P- and S-waves rose slightly to stability, and acoustic emission activity was weak (0.04% and 2.66%, respectively). Subsequently, S-wave velocity slowly declined and AE events become more active, with about 13.8% of the total in the stabilized-growth cracks stage. When the salt rock entered the accelerated-growth cracks stage, AE events increased to 75.27%; with features of an earthquake swarm, the velocities of P- and S-waves began to fall significantly. After the peak stress, salt rock produced only a small number of AE events. The beginning stress of rock damage and dilatancy were about 42–50% and 62–67% of the uniaxial compressive strength, respectively. The ultrasonic wave velocity ratio, Ib-value, and r-value effectively predicted rock failure, but the r-value was superior owing to its sensitivity and ease of measurement.

Design of ultrasonic testing device for fatigue damage of pressure vessels

The container fatigue damage detection device is researched and designed for the fatigue damage detection requirements of pressure vessels. The hardware design of the detection device, the corresponding detection technology and the functions realized are introduced. The new test performs ultrasonic nondestructive testing by driving five DC servo motors to drive the mechanical part of the test device. Research on the detection system and technology to automate the detection of fatigue damage in pressure vessels.

A traveling wave ultrasonic motor with a metal/polymer-matrix material compound stator

This study proposes a traveling wave ultrasonic motor with a metal/polymer-matrix material compound stator. The stator is composed of a metal ring and polymer-matrix teeth. The resonance frequency of the stator with different structural dimensions was analyzed by the finite element method. From the results, the structure parameters of the metal ring were obtained. The effects of the density and elastic modulus of the tooth material on the resonance frequency were also investigated. A viscoelastic contact model was built to explore the contact state between the compound stator and rotor. Considering the density, elastic modulus and tribological properties, the tooth material was prepared by a molding process. The load–torque and efficiency–torque characteristics of the motor with different tooth thicknesses were measured under different preloads using a preload controlled ultrasonic motor test device. The maximum no-load speed of the motor was about 85 r min−1 with a tooth thickness of 3 mm and a preload of 100 N, the maximum stall torque of the motor was about 0.5 N · m with a tooth thickness of 4 mm and a preload of 125 N, and a maximum efficiency of about 5.5% occurred with a tooth thickness of 4 mm, a preload of 100 N and a torque of 0.3 N · m. The main merits of the proposed ultrasonic motor are low cost, light weight, high processing efficiency and long life.