Ultrasonic C-scan inspection of brazed joint in thin panel honeycomb structure

The non-destructive testing of brazed joint in honeycomb structure with thin panel （ thickness ： 0. 2 mm） was studied by ultrasonic C-scan method. Samples with different types of artificial defect were designed; the characteristic signal and the main parameters of the test were determined by the pre-experiment, and then parameters were optimized by orthogonal design, finally the optimum process was verified by a single panel sample. The multiple reflection echoes were chosen as the characteristic signal. The optimal C-scan results were achieved when the 20 MHz focus probe was used, and the pass band range for received signal were selected as 8 - 17. 5 MHz. The defects such as incomplete penetration and core damage can be detected with ultrasonic C-scan, and the detection accuracy can reach to 1 ram.

Ultrasonic C-scan Detection for Stainless Steel Spot Welding Based on Wavelet Package Analysis

An ultrasonic test of spot welding for stainless steel is conducted. Based on wavelet packet decomposition, the ultrasonic echo signal has been analyzed deeply in time - frequency domain, which can easily distinguish the nugget from the corona bond. The 2D C-scan images produced by ultrasonic C scan which contribute to quantitatively calculate the nugget diameter for the computer are further analyzed. The spot welding nugget diameter can be automatically obtained by image enhancement, edge detection and equivalent diameter algorithm procedure. The ultrasonic detection values in this paper show good agreement with the metallographic measured values. The mean value of normal distribution curve is 0.006 67, and the standard deviation is 0.087 11. Ultrasonic C-scan test based on wavelet packet signal analysis is of high accuracy and stability.

Ultrasonic C-scanning imaging inspection of superplastic solid-state welded joint quality

Based on a large amount of dissection at welded interface and quantitative microscopic examination of welded rate, the suitable limit grey scale value was determined, and the welded rate of superplastic solid state welding interface of heterogeneous steel was systematically studied by means of self made ultrasonic C scanning imaging inspection system. The experimental results show: the welded state of superplastic solid state welding interface of heterogeneous steel can be conducted to be more accurately, reliably and quickly inspected by means of this system, and the ultrasonic testing results are good consistent with actual examination results of the interface defective distribution. Within the extent of the suitble welded rate,the welded rate in 40Cr/T10A superplastic welding process tested by this system is linear with its tensile strength of joint.

Rapid ultrasonic C-scan on image test for spot welding based interpolation

In this paper, ultrasonic C-scan test of spot welds for stainless steel has been studied. It is concluded that large scanning step length contributes to high testing efficiency, however, the low-resolution C-scan image generated cannot be used to assess spot welding quality reliably. Based on bicubic image interpolation, the C-scan image in low resolution with the large step length 1 000 ~xm is subdivided and reconstructed. By this means, the C-scan image resolution is greatly enhanced and testing results obtained are satisfactory, realizing rapid assessment of spot welds. The results of rapid ultrasonic C-scan test fit the actual metallographic measured value well. Mean value of normal distribution of error statistics is O. 006 67, and the standard deviation is O. 087 11. Rapid ultrasonic C-scan test based on image interpolation is of high accuracy and excellent stability.

Analysis of ultrasonic C-scan image features and image processing for spot welding

A focused ultrasonic transducer is used for precise, step-by-step, surface ultrasonic svanuing iusgection of spot welds. Two methods for generating characteristic data matrices of ultrasonic echo signals of the spot welds are established. One is based on the ultrasonic echo amplitude and the other is based on frequency spectrum. Both methods generate scamping inspection data arrays and provide clear C-scan images. Based on C-scan noise reduction, the Krisch edge detection operator for edge detection-a gray window transform-reflects the shapes of the spot welds and allows quantitative determination of their size. The method based on the ultrasonic echo amplitude provides a greater quantitative detection accuracy.

Comparative analysis of single-crater parameters in ultrasonic-assisted and unassisted micro-EDM of Ti6Al4V using discharge plasma imaging

Ultrasonic-assisted micro-electro-discharge machining(EDM)has the potential to enhance processing responses such as material removal rate(MRR)and surface finish.To understand the reasons for this enhancement,the physical mechanisms responsible for the individual discharges and the craters that they form need to be explored.This work examines features of craters formed by single discharges at various parameter values in both conventional and ultrasonic-assistedEDM of Ti6Al4V.High-speed imaging of the plasma channel is performed,and data on the individual discharges are captured in real-time.A 2D axisymmetric model using finite element software is established to model crater formation.On the basis of simulation and experimental results,a comparative study is then carried out to examine the effects of ultrasonic vibrational assistance on crater geometry.For every set ofEDM parameters,the crater diameter and depth from a single discharge are found to be higher in ultrasonic-assistedEDM than in conventionalEDM.The improved crater geometry and the reduced bulge formation at the crater edges are attributed to the increased melt pool velocity and temperature predicted by the model.

Microstructure and forming mechanism of metals subjected to ultrasonic vibration plastic forming: A mini review

Compared with traditional plastic forming,ultrasonic vibration plastic forming has the advantages of reducing the forming force and improving the surface quality of the workpiece.This technology has a very broad application prospect in industrial manufactur-ing.Researchers have conducted extensive research on the ultrasonic vibration plastic forming of metals and laid a deep foundation for the development of this field.In this review,metals were classified according to their crystal structures.The effects of ultrasonic vibration on the microstructure of face-centered cubic,body-centered cubic,and hexagonal close-packed metals during plastic forming and the mech-anism underlying ultrasonic vibration forming were reviewed.The main challenges and future research direction of the ultrasonic vibra-tion plastic forming of metals were also discussed.

Damage Evolution of Ballastless Track Concrete Exposed to Flexural Fatigue Loads:The Application of Ultrasonic Pulse Velocity,Impact-echo and Surface Electrical Resistance Method

In order to clarify the fatigue damage evolution of concrete exposed to flexural fatigue loads,ultrasonic pulse velocity(UPV),impact-echo technology and surface electrical resistance(SR) method were used.Damage variable based on the change of velocity of ultrasonic pulse(Du) and impact elastic wave(Di)were defined according to the classical damage theory.The influences of stress level,loading frequency and concrete strength on damage variable were measured.The experimental results show that Du and Di both present a three-stages trend for concrete exposed to fatigue loads.Since impact elastic wave is more sensitive to the microstructure damage in stage Ⅲ,the critical damage variable,i e,the damage variable before the final fracture of concrete of Di is slightly higher than that of Du.Meanwhile,the evolution of SR of concrete exposed to fatigue loads were analyzed and the relationship between SR and Du,SR and Di of concrete exposed to fatigue loads were established.It is found that the SR of concrete was decreased with the increasing fatigue cycles,indicating that surface electrical resistance method can also be applied to describe the damage of ballastless track concrete exposed to fatigue loads.

Understanding the spatial interaction of ultrasounds based on three-dimensional dual-frequency ultrasonic field numerical simulation

A transient 3D model was established to investigate the effect of spatial interaction of ultrasounds on the dual-frequency ultrasonic field in magnesium alloy melt.The effects of insertion depth and tip shape of the ultrasonic rods,input pressures and their ratio on the acoustic field distribution were discussed in detail.Additionally,the spacing,angle,and insertion depth of two ultrasonic rods significantly affect the interaction between distinct ultrasounds.As a result,various acoustic pressure distributions and cavitation regions are obtained.The spherical rods mitigate the longitudinal and transversal attenuation of acoustic pressure and expand the cavitation volume by 53.7%and 31.7%,respectively,compared to the plate and conical rods.Increasing the input pressure will enlarge the cavitation region but has no effect on the acoustic pressure distribution pattern.The acoustic pressure ratio significantly affects the pressure distribution and the cavitation region,and the best cavitation effect is obtained at the ratio of 2:1(P15:P20).

A Novel On-Site-Real-Time Method for Identifying Characteristic Parameters Using Ultrasonic Echo Groups and Neural Network

On-site and real-time non-destructive measurement of elastic constants for materials of a component in a in-service structure is a challenge due to structural complexities,such as ambiguous boundary,variable thickness,nonuniform material properties.This work develops for the first time a method that uses ultrasound echo groups and artificial neural network(ANN)for reliable on-site real-time identification of material parameters.The use of echo groups allows the use of lower frequencies,and hence more accommodative to structural complexity.To train the ANNs,a numerical model is established that is capable of computing the waveform of ultrasonic echo groups for any given set of material properties of a given structure.The waveform of an ultrasonic echo groups at an interest location on the surface the structure with material parameters varying in a predefined range are then computed using the numerical model.This results in a set of dataset for training the ANN model.Once the ANN is trained,the material parameters can be identified simultaneously using the actual measured echo waveform as input to the ANN.Intensive tests have been conducted both numerically and experimentally to evaluate the effectiveness and accuracy of the currently proposed method.The results show that the maximum identification error of numerical example is less than 2%,and the maximum identification error of experimental test is less than 7%.Compared with currently prevailing methods and equipment,the proposefy the density and thickness,in addition to the elastic constants.Moreover,the reliability and accuracy of inverse prediction is significantly improved.Thus,it has broad applications and enables real-time field measurements,which has not been fulfilled by any other available methods or equipment.

Hybrid pedestrian positioning system using wearable inertial sensors and ultrasonic ranging

Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration structure.This paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint model.In addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial sensors.Finally,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall system.Experimental results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios.

Detection of internal crack growth in polyethylene pipe using guided wave ultrasonic testing

Despite the success of guided wave ultrasonic inspection for internal defect detection in steel pipes,its application on polyethylene(PE)pipe remains relatively unexplored.The growth of internal cracks in PE pipe severely affects its pressure-holding capacity,hence the early detection of internal cracks is crucial for effective pipeline maintenance strategies.This study extends the scope of guided wave-based ultrasonic testing to detect the growth of internal cracks in a natural gas distribution PE pipe.Laboratory experiments and a finite element model were planned to study the wave-crack interaction at different stages of axially oriented internal crack growth with a piezoceramic transducer-based setup arranged in a pitch-catch configuration.Mode dispersion analysis supplemented with preliminary experiments was performed to isolate the optimal inspection frequency,leading to the selection of the T(0,1)mode at 50-kHz for the investigation.A transmission index based on the energy of the T(0,1)mode was developed to trace the extent of simulated crack growth.The findings revealed an inverse linear correlation between the transmission index and the crack depth for crack growth beyond 20%crack depth.

Analysis of Ultrasonic Emulsification Surgery and Small Incision Cataract Extracapsular Extraction Surgery for Cataract Clinical Treatment Level Improvement

Objective:To analyze the efficacy of ultrasonic emulsification and small incision cataract extracapsular extraction in cataract patients.Methods:96 cataract patients admitted from May 2021 to May 2023 were selected and randomly grouped into group A(ultrasonic emulsification)and group B(small-incision extracapsular cataract extraction),with 48 cases each.Results:At 1 week,1-month,and 3 months post-operation,the visual acuity of group A was higher and the astigmatism value was lower than that of group B(P<0.05);at 12h,24h,and 48h post-operation,the intraocular pressure of group A was higher than that of group B(P<0.05);the thickness of macular area of group A was lower than that of group B at 1 week and 1-month post-operation(P<0.05).Conclusion:Ultrasonic emulsification in cataract patients was slightly better than small incision cataract extracapsular extraction in correcting astigmatism,improving visual acuity,and regulating macular thickness.However,due to the high energy of ultrasonic emulsification,the risk of complications such as high postoperative intraocular pressure was higher.Small-incision extracapsular cataract extraction has better application value in economically disadvantaged areas.

Clinical Efficacy of Ultrasonic Medicinal Penetration in the Removal of Blood Stasis and Alleviation of Zhuyu Juanbi Formula in the Treatment of Peripheral Neuropathy Induced by Paclitaxel

Objective: To observe the clinical efficacy and differences of the Zhuyu Juanbi formula delivered through ultrasound at Zusanli on patients with chemotherapy-induced peripheral neuropathy (CIPN) due to paclitaxel injection. Methods: A total of 72 breast cancer patients with CIPN were randomly divided into two groups. The treatment group (36 cases) was treated with oral methylcobalamin plus ultrasonic medicine permeating Zhuyu Juanbi formulae, while the control group (36 cases) was treated with oral methylcobalamin alone. Following two 2 cycles of continuous treatment, the efficacy of peripheral neurotoxicity, TCM syndrome score, FACT/GOG-Ntx score, total neuropathy score, and safety indicators of gynecological cancer patients were observed in the two groups. Result: In the treatment of CIPN, the addition of ultrasonic medicine permeating Zhuyu Juanbi formulae was more effective than oral methylcobalamin alone in reducing peripheral neurotoxicity and improving the quality of life of patients. The difference between the two groups was statistically significant (P < 0.05), and ultrasound drug penetration Zhuyu Juanbi formulae significantly reduced the FACT/ GOG-Ntx score and TNS score in the treatment group. In terms of drug safety, it rarely caused adverse reactions such as grade 3 and 4 leukopenia, and the safety profile was therefore good. Conclusion: The combination of ultrasonic medicine permeating Zhuyu Juanbi formulae and methylcobalamin has been demonstrated to be an effective treatment for peripheral neurotoxicity in patients with PIPN. It has been shown to significantly improve the clinical symptoms of PIPN patients, improve the quality of life of patients, and have a good safety profile.

Structure and allergenicity of a-lactalbumin:effects of ultrasonic prior to glycation and subsequent phosphorylation

Bovineα-lactalbumin(BLA)induced severe cow's milk allergy.In this study,a novel strategy combining ultrasonication,performed before glycation,and phosphorylation was proposed to reduce BLA allergenicity.Result showed that IgE-and IgG-binding capacities and the release rates of histamine and interleukin-6 from RBL-2 H3 were reduced.Moreover,intrinsic fluorescence intensity and surface hydrophobicity were decreased,whereas glycated sites(R10,N44,K79,K108,N102 and K114)and phosphorylated sites(Y36 and S112)of BLA were increased.Minimum allergenicity was detected during BLA treatment after ultrasonic prior to glycation and subsequent phosphorylation because of considerable increase in glycated and phosphorylated sites.Therefore,the decrease in allergenicity of BLA,the effect correlated well with the shielding effect of glycated sites combined with phosphorylated sites and the conformational changes.This study provides important theoretical foundations for improving and using the ultrasonic technology combined with protein modification in allergenic protein processing.

Simultaneous measurement of velocity profile and liquid film thickness in horizontal gas–liquid slug flow by using ultrasonic Doppler method

Horizontal gas-liquid two-phase flows widely exist in chemical engineering,oil/gas production and other important industrial processes.Slug flow pattern is the main form of horizontal gas-liquid flows and characterized by intermittent motion of film region and slug region.This work aims to develop the ultrasonic Doppler method to realize the simultaneous measurement of the velocity profile and liquid film thickness of slug flow.A single-frequency single-channel transducer is adopted in the design of the field-programmable gate array based ultrasonic Doppler system.A multiple echo repetition technology is used to improve the temporal-spatial resolution for the velocity profile.An experiment of horizontal gas-liquid two-phase flow is implemented in an acrylic pipe with an inner diameter of 20 mm.Considering the aerated characteristics of the liquid slug,slug flow is divided into low-aerated slug flow,high-aerated slug flow and pseudo slug flow.The temporal-spatial velocity distributions of the three kinds of slug flows are reconstructed by using the ultrasonic velocity profile measurement.The evolution characteristics of the average velocity profile in slug flows are investigated.A novel method is proposed to derive the liquid film thickness based on the instantaneous velocity profile.The liquid film thickness can be effectively measured by detecting the position and the size of the bubbles nearly below the elongated gas bubble.Compared with the time of flight method,the film thickness measured by the Doppler system shows a higher accuracy as a bubble layer occurs in the film region.The effect of the gas distribution on the film thickness is uncovered in three kinds of slug flows.

Mechanism of ultrasonic strengthening fluidity of low mature shale oil: A case study of the first member of Lucaogou Formation, western Jimusaer Sag, Northwest China

The low mature shale oil resources of Lucaogou Formation in Jimusar Sag have a great potential, but the heavy oil quality limits large-scale economic development significantly. Ultrasonic is a typical representative of heavy oil viscosity reduction and anhydrous fracturing technology, and how to understand the action characteristics and mechanism of ultrasonic effect on reservoir is a critical issue to enhance shale oil production in the industrialized application of power ultrasonic. Therefore, the comparative experiments with different time of power ultrasonic loading were conducted to analyze the response mechanism of reservoir characteristics and the change of fluid mobility. The results indicate that the ultrasonic treatment is ameliorative to the pore-fracture structure, and the improvement degree is controlled by the mechanical vibration and cavitation of ultrasound. Generally, the location with weak cementation strength or relatively developed microcrack is preferred to pore expansion. After the ultrasonic treatment, the shale oil quality becomes lighter, and the transformation of shale oil from adsorbed to free, is accelerated due to enhanced fluidity. Pore-expanding effect and fluid mobility enhancement are essential aspects of the power ultrasonic loading to improve the recovery of low mature shale oil. The results of this study support the feasibility analysis of ultrasonic enhanced shale oil exploitation theoretically.

Modeling the hydration,viscosity and ultrasonic property evolution of class G cement up to 90℃ and 200 MPa by a scale factor method

A comprehensive experimental program has been performed to characterize the hydration and engineering property evolution of a class G oil well cement under various curing temperatures from 30 to 90℃.The progress of hydration was monitored by isothermal calorimetry(atmospheric pressure);the viscosity evolution was measured using a high temperature and high pressure consistometer(up to 200 MPa);the ultrasonic property development was evaluated by an ultrasonic cement analyzer(up to 100 MPa).Test results indicate that the influences of curing temperature and pressure on the hydration,viscosity and ultrasonic property development can be modeled by a scale factor method that is similar to the maturity method used in the concrete industry.However,the key parameters of the scale factor model,namely the apparent activation energy and the apparent activation volume of cement showed obvious variations with test method and curing condition.The test results indicate that the curing temperature has a stronger effect on cement hydration rate than viscosity and ultrasonic property development rate,while the curing pressure has a much stronger influence on cement slurry properties before setting(viscosity)than after setting(ultrasonic property).

A comparative study for determining rock joint normal stiffness with destructive uniaxial compression and nondestructive ultrasonic wave testing

Rock joints are one of the vital discontinuities in a natural rock mass.How to accurately and conveniently determine joint normal stiffness is therefore significant in rock mechanics.Here,first,seven existing methods for determining joint normal stiffness were introduced and reviewed,among which MethodⅠ(the indirect measurement method),MethodⅡ(the direct determination method),MethodⅢ(the across-joint strain gauge measurement method)and MethodⅣ(the deformation measuring ring method)are via destructive uniaxial compression testing,while MethodⅤ(the best fitting method),MethodⅥ(the rapid evaluation method)and MethodⅦ(the effective modulus method)are through wave propagation principles and nondestructive ultrasonic testing.Subsequently,laboratory tests of intact and jointed sandstone specimens were conducted following the testing requirements and pro-cedures of those seven methods.A comparison among those methods was then performed.The results show that Method I,i.e.the benchmark method,is reliable and stable.MethodⅡhas a conceptual drawback,and its accuracy is acceptable at only very low stress levels.Relative errors in the results from MethodⅢare very large.With MethodⅣ,the testing results are sufficiently accurate despite the strict testing environment and complicated testing procedures.The results from MethodⅤare greatly unstable and significantly dependent on the natural frequency of the transducers.The joint normal stiffness determined with MethodⅥis stable and accurate,although data processing is complex.MethodⅦcould be adopted to determine the joint normal stiffness corresponding to the rock elastic deformation phase only.Consequently,it is suggested that MethodsⅠ,ⅣandⅥshould be adopted for the mea-surement of joint normal stiffness.The findings could be helpful in selecting an appropriate method to determine joint normal stiffness and,hence,to better solve discontinuous rock mass problems.

A novel method towards improving the hydrogen storage properties of hypoeutectic Mg-Ni alloy via ultrasonic treatment

Ultrasonic treatment has great contributions on modifying the morphology,dimension and distribution of constituent phases during solidification,which serve as dominate factors influencing the hydrogen storage performance of Mg-based alloys.In this research,ultrasonic treatment is utilized as a novel method to enhance the de-/hydriding properties of Mg-2Ni(at.%)alloy.Due to ultrasonic treatment,the microstructure of as-cast alloy is significantly refined and homogenized.Ascribing to the increased eutectic boundaries and shortened distance insideα-Mg for hydrogen atoms diffusion,the hydrogen uptake capacities and isothermal de-/hydriding rates improve effectively,especially at lower temperature.The peak desorption temperature reduces from 392.99°C to 345.56°C,and the dehydriding activation energy decreases from 101.93 k J mol^(-1)to 88.65 k J mol^(-1).Weakened hysteresis of plateau pressures and slightly optimized thermodynamics are determined from the pressure-composition isotherms.Owing to the refined primary Mg,a larger amount of hydrogen with the higher hydriding proportion is absorbed in the first stage when hydrides nucleate in eutectic region and grow on primary Mg periphery subsequently before MgH2colonies impinging,resulting in the enhancement of hydrogenation rates and capacities.