Abstract The eddy current skin-effect limits the detection of subsurface defects and range thickness measurement. Traditional concepts to estimate penetration depth basing on plane wave propagation into a conducting halfspace cannot describe real inspection achievable by state-of-the-art sensors instruments. paper presents more fruitful concept for estimating noise limited depth. Here, traditional parameters like frequency, probe dimensions, conductivity permeability are analysed in...

The features of the hodographs signals a low-frequency eddy current (EC) probes double-differentiation type with an operational diameter 6 mm in complex plane during scanning layered aluminum alloy specimen artificial crack-like defects oriented at different angles inclination to tested surface were investigated. research was conducted frequency kHz using board EDDYMAX type. analyzed depending on inclination, depth location and lift-off between EC probe surface. Based analysis shape from...

Abstract Well-timed detection of the defects (e.g., fatigue cracks and corrosive damages) in aircraft structures is question vital importance. Periodic in-service non-destructive inspection (NDI) necessary to prevent expensive breakdowns during life. Eddy current (EC) NDI method have many advantages for due high mobility possibility detect without direct contact with inspected surface (even through a protective coating removal). Last decades some enhanced EC techniques were developed...

Abstract It is known that during operation, the aircraft construction materials are exposed to significant mechanical loads and changes in temperature for a very short period of time. All this leads various defects damages assemblies units need be inspected safe operation aircraft, their assemblies, units. In some cases, implementation inspection or diagnostic accompanied by emergence technical difficulties caused large size limited access local places. Under such conditions, ensuring...

Abstract Aircraft, their assemblies, and units must provide high durability reliability, maintain mechanical technological characteristics throughout the life span of aircraft. Different elements aircraft structures work under loads, over a wide temperature range, with varying degrees exposure to corrosive environments. Aircraft structural materials have variation in values require various testing methods for inspection. In many NDT applied aviation testing, signals that could be represented...

Abstract Eddy current (EC) method is considered as most applicable for in-service detection of fatigue subsurface cracks initiated in aircraft multilayer structures near the rivet holes. At same time, successful solution this problem obstructed by additional noise created defect-free rivets. All EC inspection techniques around rivets can be classified into three main groups: 1) static mode – carried out placing probe concentrically on head; 2) rotational when rotated axle and sliding...

The specimens of D16ATHB and B95T1 aluminum alloys (like 2024T3 7075T6 alloys, respectively) cut out from lower upper wing skins AN-12 aircraft after 40 years exploitation are investigated. dependencies between mechanical characteristics electrical conductivity obtained for long-term exploited show a radically different trend in comparison with known as-received state various heat treatments. Such data explained by results materials fine structure study. Nondestructive eddy current (EC)...

Nondestructive testing (NDT) methods are widely used for inspection of long term exploited structures as important part maintenance strategy. NDT can create the background material optimization under engineering procedures (e.g., welding) influence also. Principal attention taken into consideration is investigation correlations between measured nondestructively properties specific electrical conductivity, coercive force) and parameters fatigue crack growth resistance (FCGR) needed residual...

Abstract In-service non-destructive inspection (NDI) is a very important part of the aircraft maintenance program that minimizes breakdowns due to fracture critical components. The eddy current (EC) NDI method one most applicable methods for this purpose, its high sensitivity fatigue cracks and corrosion damage in main structural materials. In paper, selective double differential type EC probes characterized by enhanced possibility detecting subsurface initiated or stress phenomena are...

ABSTRACT Eddy current array (ECA) technology is increasingly being used in the aerospace industry for non-destructive testing of aircraft components. This study evaluates performance ECA detecting defects components, focusing on its effectiveness, reliability, and sensitivity. The effectiveness eddy defectoscopy by introducing a dimensionless efficiency coefficient, then seeks to validate this coefficient through experimental component materials with artificially induced various sizes,...

Application of eddy current method for detection the cracks in ferrous steel structures and components is formidable due to additional noise originated from magnetic structural heterogeneity geometrical irregularity inspected surface. These factors throw down a real challenge EC inspection practice. Presented double differential type probes can create good background solve these problems. In this study investigations concerned with probe some specific applications are presented.

In this article is considered of experimental results using the multidifferential type a transducer at two excitation mode - pulsed and harmonic. The research was carried out on plates-type samples made steel aluminium alloy which had artificial defects like crack. It has been described analysis procedure signals informative parameters from transducer. signal amplitude, decrement frequency natural oscillations have used as excitation. harmonic equivalent to given evaluation electric...

Abstract A review of the existing literature shows that modern pulsed eddy current (PEC) technique for flaw detection in aircraft structure inspection is typically carried out aperiodic mode. Аt same time, unstable characteristic points EC signal usually used as informative parameters can restrict potential this excitation mode due to significant measurement errors. This article considers an advanced PEC method NDT based on oscillatory To obtain conditions concerned with different modes...

It is known that in the process of operation materials aircraft construction are exposed to significant mechanical loads and temperature changes (fluctuations) for a very short period time. All this leads various defects damages assemblies units which need be inspected safe aircraft, their assemblies, units. In some cases, implementation inspection or diagnostic accompanied by technical difficulties caused large size of-aircraft limited access local places. such conditions, it becomes...

Coercive force, which is one of the structure-sensitive characteristics ferromagnetic materials, most often used for magnetic analysis. This approach requires use powerful magnetization systems, leads to an increase in size attachable probe and, accordingly, a decrease locality control. The above-mentioned disadvantages can be eliminated by using parameters dynamic hysteresis loop (MHL), involves variable fields. A device studying MHL during cyclic remagnetization tasks testing namely...