Dynamic Nondestructive Testing Research Articles

Enhancing Preamplifier Design for Acoustic Emission Detection Instrument

With the development of the industry, the safety of pressure vessels is crucial for both production and personnel safety. The application of acoustic emission testing technology as a dynamic non-destructive testing method in the detection of pressure vessels is becoming increasingly prevalent. This paper presents the design of a low-frequency acoustic emission preamplifier with a frequency range of 30KHz to 200KHz and a gain of 20dB. The preamplifier is composed of amplification circuits, power supply circuits, and filtering components. By utilizing the PXR04 series high-sensitivity resonant acoustic emission sensor and Texas Instruments' OPA333 operational amplifier, along with a clever power supply design, effective signal amplification and system stability are ensured. Experimental results validate the correctness of the design, providing a feasible and effective solution for enhancing the performance of acoustic emission testing equipment.

Ultrasonic monitoring of cement setting based on embedded sensor

The hydration property of cement directly affects the performance index of concrete, so it is necessary to monitor the hydration setting process of cement. The aim of this paper is to monitor the process of cement hydration setting by ultrasonic wave. Ultrasonic monitoring is a kind of dynamic non-destructive testing technology, which has the advantages of real-time, on-line and continuous. In this paper, an in-situ monitoring technology of cement hydration setting based on embedded piezoelectric ceramic sensor is introduced. The monitoring results show that the amplitude change of ultrasonic signal received by the sensor can indirectly reflect the change process of cement hydration solid and liquid, especially the initial setting node has a high catching ability.

Monitoring Corrosion of Steel Bar in Concrete Using Ultrasonic Wave

The problem of steel corrosion in reinforced concrete structure is very serious. The purpose of this paper is to monitor steel corrosion by ultrasonic guided wave. Ultrasonic guided wave monitoring is a kind of dynamic nondestructive testing technology, which has the advantages of real-time, on-line and continuous. In this paper, an ultrasonic in-situ monitoring technique of steel bar corrosion based on embedded piezoelectric ceramic sensor is introduced. Based on this, ultrasonic guided wave was used to monitor mortar samples with different strengths of uniform corrosion, and scanning electron microscopy was used to observe the interface between reinforcement and concrete at different corrosion stages. The results show that the variation trend of ultrasonic guided wave amplitude can reflect the degree of corrosion. Mortar with different strength will affect the time and trend of corrosion. The scanning electron microscopy (SEM) method shows that the changing process of the interface between reinforcement and concrete is consistent with the trend of ultrasonic guided wave.

Anisotropy of Young's Modulus of DD6 from 25 to 1200 °C Based on Nondestructive Dynamic Method

The Young's modulus is an essential factor for improving turbine blade design. The present study aims to obtain the flexural frequencies (f1) and corresponding dynamic Young's modulus (Ed) of Ni‐based single‐crystal DD6 across a temperature range of 25–1200 °C using a nondestructive dynamic testing method. The relationship between the elastic constants and various crystal orientations is derived by employing the transformation of the elastic matrix. In addition, finite element (FE) simulation is conducted to calculate the flexural frequency (f1) of the [001] crystal orientation. The findings indicate that the dynamic Young's modulus (Ed) decreases as the temperature increases within the range of 25–1200 °C. Furthermore, the Ed values for different crystal orientations follow the trend: Ed[1] < Ed[11] < Ed[111]. This suggests significant anisotropy in the material. The normalized model, matrix transformation calculation method, and finite element method demonstrate high accuracy in predicting the elastic modulus of DD6, as evidenced by the good correspondence between the fitting curves obtained using the normalization method and the test results. These results have practical applications in engineering, particularly in turbine blade design and other applications, and serve as valuable references for mechanical property testing and finite element simulations.

Minimally Invasive Arthrodesis of the Equine Proximal Interphalangeal Joint: A Biomechanical Comparison of Three 5.5-mm Cortical Screws Inserted in Lag Fashion and Two 7.0-mm Headless Cannulated Dual-Pitch Compression Screws.

The aim of this study was to compare the biomechanical properties of two minimally invasive arthrodesis techniques of the equine proximal interphalangeal (PIP) joint (three transarticular 5.5-mm cortical screws [AO-3TLS] vs. two transarticular 7.0-mm headless cannulated multi-use compression screws [MUC-2TS]) in dynamic non-destructive testing and compression testing to failure. The experimental study included six pairs of cadaveric adult equine forelimbs; one limb from each horse was randomly assigned to one of the treatments, and the contralateral limb was submitted to the remaining treatment. The dynamic test was performed alternating non-destructive compression tests at a displacement rate of 5 mm/min up to 5,000 N and sinusoidal compressive cyclic tests at 6 Hz, using a 3,600-N amplitude for 8,550 cycles. Construct stiffness and maximum sagittal plane rotation about the PIP joint markers were determined during the dynamic test. After the dynamic test reached 136,800 cycles, the monotonic compressive test until failure was performed on each construct: load, displacement and sagittal plane rotation about the PIP joint marker at failure were analysed. The evaluated biomechanical properties showed no statistical difference between the AO-3TLS and MUC-2TS treatment groups in any of the ramps of the dynamic non-destructive test and in the compression loading until failure test. The MUC-2TS treatment produced biomechanical properties equivalent to the AO-3TLS treatment for PIP joint arthrodesis.

Cyclic aging monitoring of lithium-ion battery based on acoustic emission

ABSTRACT A timely and accurate understanding of the state of health (SOH) of lithium-ion batteries is essential for early detection and prediction of their potential safety risks. Acoustic emission (AE) can perform dynamic non-destructive testing of lithium-ion batteries under normal charge-discharge cycles, and detect the deformation of internal electrodes of the battery behavior. In this paper, firstly, the whole aging process of lithium-ion batteries and recorded AE signals are monitored. Secondly, the waveform and signal time interval from AE signals during battery aging in the time domain is extracted. Thirdly, the spectrum of AE signals is analyzed. The experimental results show that the total number of AE signals will change with the decline of battery capacity and SOH. The turning point in the time interval waveform of the battery AE signal can be used to identify the constant current or voltage charging mode. The AE signals of batteries mainly exist in two frequency bands, where the content of frequency band 1 is about 10kHz-120kHz, and the range of frequency band 2 is about 130kHz-180kHz. The maximum amplitude of frequency bands 1 and 2 shows their characteristics during the charging and discharging process.

Signal Identification of Wire Breaking in Bridge Cables Based on Machine Learning

With the booming development of bridge construction, bridge operation and maintenance have always been major issues to ensure the safety of the community. Affected by the long-term service of bridges and natural factors, the safety and durability of cables can be threatened. Cables are critical stress-bearing elements of large bridges such as cable-stayed bridges. Realizing the health monitoring of bridge cables is the key to ensuring the normal operation of bridges. Acoustic emission (AE) is a dynamic nondestructive testing method that is increasingly used in the local monitoring of bridge cables. In this paper, a testbed is described for generating the acoustic emission signals for signal identification testing with machine learning (ML) models. Owing to the limited number of measured signals being available, an algorithm is proposed to simulate acoustic emission signals for model training. A multi-angle feature extraction method is proposed to extract the acoustic emission signals and construct a comprehensive feature vector to characterize the acoustic emission signals. Seven ML models are trained with the simulated acoustic emission signals. Long short-term memory (LSTM) has been specially applied for deep learning demonstration which requires a large amount of training data. As all machine learning models (including LSTM) provide desired performance, it shows that the proposed approach of simulating acoustic emission signals can be effective.

Dynamic Testing in Support of the Seismic Assessment of a Century Old Masonry Building Complex

The vulnerability assessment of existing masonry buildings is a largely investigated research topic with some aspects still to be faced. In historic towns, masonry buildings are aggregated and together confined, and their final appearance is derived from interventions and additions during their lives in different times and with different masonry textures or different construction materials. Demolitions and reconstructions of some parts were frequent, with the difficulty of now understanding the effectiveness of the mutual constraints. The seismic assessment of a case study of a 175-year-old building complex in Udine (Italy) provides an opportunity to use the results of ambient vibration tests to face the problem of modelling aggregate buildings for their seismic assessment. The “Padiglione Lodi” building complex was built in 1847 and extended and renovated several times afterwards. It was built mostly using URM with limited use of reinforced concrete. It consists of a main building and three wings (western, central and eastern). The inspections, experimental survey and analysis of the available documentation are used to suitably calibrate a Finite Element Model of the whole complex. Moreover, this allows the singling out of the central wing, as the unit needs more careful investigation. Non-destructive dynamic testing is then applied to the central wing in order to further validate the model and improve the knowledge of the interaction of the unit with the rest of the building. General remarks on the effective application of non-destructive dynamic analysis in conjunction with other methods to the seismic assessment of large URM building complexes are drawn.

Safety Evaluation of Quayside Container Crane based on Stress Test

Due to the long service life of a quayside container crane in an enterprise, there is slight corrosion on the surface of metal structure, which has potential safety hazard. In order to master the technical condition of the metal structure of the crane, the stress distribution and change information of the crane are obtained by dynamic and static stress testing and non-destructive testing. According to the analysis and test results, the safety assessment of the whole machine is completed and reasonable management suggestions are put forward.

Avaliação do potencial de uso do deflectômetro de impacto leve para medidas de deflexão em pavimentos urbanos

O objetivo principal deste estudo foi avaliar o potencial de uso do Deflectômetro de Impacto Leve (LFWD) para medir deflexões em pavimentos urbanos. Para isso, avaliaram-se medidas de deflexões aferidas pelo LFWD, viga Benkelman (VB) e o ensaio de carga com placa (PL) em pavimentos construídos com diferentes materiais, espessuras de revestimento asfáltico e idades de operação. Determinaram-se modelos de regressão linear, que relacionaram as medidas de deflexão entre o LFWD e a VB, e o PL. Os resultados mostraram que não houveram boas relações lineares em estruturas compostas por camadas de revestimento asfáltico mais espessas, como também em estruturas com revestimento asfáltico sobre paralelepípedos. Houve boa relação linear em estruturas compostas por revestimento asfáltico mais delgado. Este estudo estimula o uso de equipamentos dinâmicos de ensaios não destrutivos para medição de deformações elásticas para o projeto de manutenção e reabilitação de vias de baixo volume de tráfego.

A Full-Scale Experimental Study of the Vertical Dynamic and Static Behavior of the Pier-Cap-Pile System

The bearing capacity evaluation of bridge substructures is difficult as the static loading test (SLT) cannot be employed for the bridges in services. As a type of dynamic nondestructive test technique, the dynamic transient response method (TRM) could be employed to estimate the vertical bearing capacity when the relationship between static stiffness and dynamic stiffness is known. The TRM is usually employed to evaluate single piles. For the pier-cap-pile system, its applicability should be investigated. In the present study, a novel full-scale experimental study, including both TRM test and SLT, was performed on an abandoned bridge pier with grouped pile foundation. The test included three steps: firstly, testing the intact pier-cap-pile system; then, cutting off the pier and testing the cap-pile system; finally, cutting off the cap and testing the single pile. The TRM test was repeatedly performed in the above three steps, whereas the SLT was only performed on the cap-pile system. Based on the experimental results, the ratio of dynamic and static stiffness of the cap-pile system was obtained. The results show that (1) in the low-frequency range (between 10 and 30 Hz in this study), the dynamic stiffness of the whole system is approximately four times of that of a single pile; (2) the ratio of dynamic and static stiffness of the cap-pile system tested in the study is approximately 1.74, which was similar to other tested values of a single pile; (3) to evaluate the capacity of similar cap-pile system and with similar soil layer conditions by TRM, the value of Kd/Ks tested in the study can be used as a reference.

Acoustic emission source localization method for high-speed train bogie

Bogie is one of the most critical parts of high-speed train and is directly related to the operation quality and safety of the train. However, currently no dynamic non-destructive testing method exists for real-time monitoring. Therefore, this paper proposes a new damage localization method for high-speed train bogie dynamic testing. The acoustic emission testing technology is applied to test the vulnerable welding parts of the bogie with time reversal localization method. Firstly, the bogie welding parts structure model based on finite element software is established. Then an acoustic emission damage signal is sent from the model and the acoustic emission source signal is received by the preset acoustic emission sensor. And the accurate localization of damage is achieved by dealing with the received signal according to the time reversal focusing principle and imaging the acoustic emission source. The simulation experiments show that the proposed method can accurately find the damaged localization. And finally, the method has been verified through experiment, and the results show it can effectively improve signal energy of the damage source, and the position of the damage source can be shown accurately through signal reconstruction and localization in the detection area.

On-line Monitoring by Acoustic Emission of Butt Joint Structure on the Composite Fuselage Frame

Acoustic emission (AE) technique is an online and dynamic non-destructive testing technology by diagnosing sounds, applicable to damage identification of all sorts of materials and structures. In order to fulfill the requirement of on-line monitoring for butt joint structure on the composite fuselage frame in static loading, Acoustic Emission (AE) is employed in this article. The experiment research is focused on examining the damage evolution process of the specimen subjected to mechanical tests by constantly monitoring the AE and strain responses. Combined with strain results, the recorded acoustic signals are analyzed using AE characteristic parameters such as AE amplitude and AE accumulative energy to identity five different damage stages and conclude the corresponding damage style during the entire test. The outcomes of this article can be available for supplementation and improvement of the current on-line non-destructive testing research for composite structures.

Feasibility of freeze-thaw damage analysis for asphalt mixtures through dynamic nondestructive testing

Invisible freeze-thaw damage is commonly associated with many durability problems in asphalt pavement. Therefore, the freeze-thaw damage of asphalt pavement should be detected in situ to evaluate the pavement condition. This study aimed to explore the feasibility of freeze-thaw damage analysis for asphalt mixtures through dynamic nondestructive testing. Free–free resonance testing method and Rayleigh wave testing technology were selected for this analysis. Natural frequency, damping ratio, and Rayleigh wave velocity were used to describe the freeze-thaw damage. Optimal experimental parameters were proposed by analyzing the effect of test parameters on the stability and accuracy of results. Variations in the dynamic parameters of asphalt mixtures under freeze-thaw action were analyzed. Results showed that natural frequency, damping ratio, and Rayleigh wave velocity changed regularly during the freeze-thaw process and could be used to analyze the damage after freeze-thaw cycles. The effects of different types of asphalt mixture on the dynamic test parameters during the freeze-thaw process were also examined. Nondestructive testing revealed that the type of asphalt and the gradation of asphalt mixture affected the damage degree of freeze-thaw cycles. The sensitivities of the different test parameters of the freeze-thaw damage were compared via principal component analysis, and the second-order damping ratio was proposed as a reasonable parameter to identify the in situ freeze-thaw damage in asphalt pavement.

291. Influence of lumbar lordosis on posterior rod strain in long-segment pedicle screw and rod instrumentation with anterior column realignment: cadaveric study

BACKGROUND CONTEXT Lumbar lordosis (LL) has a close geometric relationship with pelvic parameters and sagittal profile. The association between the alignment of the pelvis (sacral slope) and the lumbar spine is an important determinant of sagittal balance, with the lower arc of lordosis being the most important determinant of the global lordosis. Posterior rod strain (RS) monitoring during biomechanics tests is an effective method to infer the stress on spinal implants. Yet it remains unknown whether lumbar lordosis and final construct geometry have a significant impact on instrumentation loading. An improved understanding of key factors that influence stress and strain in spinal instrumentation may serve to maximize construct longevity and avoid implant failure. PURPOSE Investigate the relationship between lordosis angle in different levels and different conditions with rod strain during loading. METHODS Seven fresh-frozen specimens underwent standard dynamic nondestructive bending tests in flexion (FL), extension (EX) (7.5 Nm) as well as compression (C) (400N) in a 6DOF robotic apparatus. Conditions tested were: 1) intact; 2) pedicle screws and rods only (PSR); 3) Anterior column realignment at L3-L4 (ACR). The posterior right rod at L3-L4 and at L5-S1 was instrumented with strain gauges. Lateral x-rays of all conditions were taken before testing. Lumbar lordosis spanning different levels were measured in all different conditions (unloaded) using the Cobb method (L5-S1, L4-S1, L3-S1, L2-S1 and L1-S1) and correlated with rod strain (RS) (during loading) using a Pearson correlation analysis (p RESULTS L3-S1 intact (P=0.028) and PSR (p=0.007) lordotic angle demonstrated strong correlation with L3-4 RS in PSR condition during FL. The L3-S1 intact angle also correlated with RS with PSR in EX (p=0.018). L3-S1 intact angle demonstrated a relationship with L5-S1 RS with ACR during C (p=0.008). L2-S1 intact angle also demonstrated a correlation with L3-4 RS with PSR during FL (p=0.007) and EX (p=0.002). The L2-S1 intact lordosis was linked with L5-S RS with PSR during FL (p=0.03) and with ACR during compression (p=0.03). All correlations were positive (i.e. strains increased in magnitude with increasing Cobb angles). CONCLUSIONS Different lumbar lordotic measures taken in intact and PSR conditions demonstrated strong correlations with in vitro posterior RS. Both native lumbar curvature and after placement of pedicle screw and rod instrumentation have a significant influence on in vitro posterior hardware strain changes during loading. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Modulus of elasticity and Poisson's ratio of fiber-reinforced concrete in Colombia from ultrasonic pulse velocities

Modulus of elasticity and Poisson's ratio are the main mechanical properties of concrete for assessing the flexural and shear stiffness of concrete elements. Although steel fibers are beginning to be accepted in modern building codes, equations for estimating the elasticity modulus and Poisson's ratio of Fiber Reinforced Concrete (FRC) are not provided in such building codes. Even though the direct measurement of the modulus of elasticity and the Poisson's ratio is adequately established, the use of non-destructive methods such the Ultrasonic Pulse Velocity (UPV) test offers an economical and easy alternative that must be explored. The aim of this paper is to propose empirical relationships for estimating the dynamic modulus of elasticity and Poisson's ratio of concrete reinforced with steel, synthetic and hybrid fibers, using results measured during the UPV tests. The research is also intended to assess results of models reported in a literature review, to evaluate the effect of test setup (direct, semi-direct and direct), and to establish a relationship between the dynamic modulus of elasticity of FRC and the characteristics of steel, polypropylene/polyethylene and hybrid fibers. The experimental program included dynamic non-destructive tests and static destructive tests of 29 concrete specimens. The variables included in the experimental program were the fiber type (steel, synthetic and hybrid), the fiber content and the ultrasonic pulse velocity setup (direct and semi-direct). The length, diameter and aspect ratio of fibers were 50 mm, 1.05 mm and 48 for the steel fibers, and 50 mm, 0.68 mm and 74 for the polypropylene/polyethylene synthetic fibers. Fiber volume fractions in the concrete varied between 0.17% and 0.93%. The study also compared the results obtained in the static tests with the dynamic results, in order to identify the differences between static and dynamic behavior.

Comparison between Destructive and Nondestructive Dynamic Tests in the Presence of Different Ions as the Curing Solution

Comparison between Destructive and Nondestructive Dynamic Tests in the Presence of Different Ions as the Curing Solution

Challenges due to problematic soils: a case study at the crossroads of geotechnology and sustainable pavement solutions

Geotechnical characteristics of subsoils should be adequately incorporated in the rehabilitation strategies of existing pavements which have performed poorly due to problematic subsurface conditions. However, there appears to be a disconnect between the advances in our understanding of the mechanics of soft or problematic soils and the rehabilitation design of the overlying pavement structure, leading to repeated cycles of premature distresses, underperformance, and failures. A case study is presented for the rehabilitation of a flexible pavement built over soft organic soils in Southeastern Florida, USA. The study incorporates forensic investigation of the deteriorated pavement structure, subsurface investigations with cone penetration testing, design and construction of reinforced overlays in field test sections, and long-term performance monitoring with non-destructive dynamic tests. Efforts are made to correlate site characteristics with pavement performance. Based on the secondary compression behavior of the organic soils, cement deep mixing criteria are proposed for a more durable and sustainable solution.

Application of Impact Vibration Test Method for Bridge Substructure Evaluation

The bridge foundations are constructed mainly below ground or water level. The rehabilitation of a foundation is difficult, and the results of evaluation of structural conditions are usually inaccurate. Furthermore, there are many cases that after natural disasters such as earthquakes, typhoons and floods, it is required to rapidly evaluate bridge substructure conditions for a judging decision on being able to open the bridge to traffic or not. Impact vibration test method has been developed to deal with such problems. Impact vibration test method is a non-destructive dynamic test method which allows to evaluate structural conditions of bridge substructures promptly with a good soundness. In this study, firstly, impact vibration test method, which is one of the utilizable non-destructive tests on the scouring of bridge substructure, is presented. Then, application of the test method for substructure evaluation of a bridge in Vietnam is introduced. The soundness and effectiveness of test method is also discussed.

Experimental Validation of Metaconcrete Blast Mitigation Properties

We provide experimental evidence of the mitigation properties of metaconcrete under blast loading. Mitigation is achieved through resonance of engineered aggregates consisting of a heavy and stiff core coated by a light and compliant outer layer. These engineered aggregates replace the standard gravel in conventional concrete. To assess experimentally the attenuation properties of metaconcrete, we have cast two batches of cylindrical specimens. The mortar matrix of the first batch consists of cement combined with a regular sand mix, while the mortar matrix of the second batch consists of cement combined with sand mix, fine gravel, and polymeric fibers. One of the specimens of each batch was cast with no aggregates, while the other two contained 40 and 60, respectively, randomly arranged 22 mm diameter commercially available computer mouse balls. We performed nondestructive dynamic tests by applying a 10 V amplitude periodic signal to one end of the specimens and measuring the amplitude of the transmitted signal received at the other end. We observed a remarkable 2 order of magnitude reduction in the amplitude of the transmitted signal in metaconcrete relative to conventional concrete.