Scattering of guided waves by circumferential cracks in steel pipes

2001 ◽  
Author(s):  
H. Bai
Keyword(s):  
Guided Waves ◽  
Steel Pipes

Non-Invasive On-Line Monitoring for Nuclear Power Plants Using Guided Waves Propagating in Steel Pipes With Different Types of Structural Complexity

2016 ◽  
Author(s):  
Francesco Bertoncini ◽  
Mauro Cappelli ◽  
Francesco Cordella ◽  
Marco Raugi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Guided Waves ◽  
Structural Complexity ◽  
Ultrasonic Waves ◽  
Steel Pipes ◽  
Non Invasive ◽  
Different Types ◽  
On Line

On-line monitoring for installed piping in Nuclear Power Plants (NPPs), as well as for Oil & Gas and other kind of plants, is crucial to early detect local ageing effects and locate single defects before they may result in critical failures. All the actions able to prevent failures are of great value especially if non-invasive and allowing an In-Service Inspection (ISI). In particular the Long Term Operation (LTO) and Plant Life Extension (PLEX) may be invalidated from radiation, thermal, mechanical stresses besides their own ageing. Hence on-line monitoring techniques are of much interest especially if they assure the required safety levels and at the same time are simple and cost-effective. Guided Waves (GW) satisfy these requirements since they are structure-borne ultrasonic waves that propagate themselves without interfering along the same pipe structure, which in turns through its geometric boundaries serves as a confining structure for the GW used to test its integrity. The frequencies used for GW testing extend up to 250 kHz, thus allowing a long-range inspection of pipes (tens of meters in favorable circumstances). The experimental conditions (e.g. temperature, complex piping structure, wall thickness, materials) have to be considered since they strongly affect the results but GW generated through magnetostrictive sensors are expected to overcome such issues due to their robustness and positioning ease. In this paper, new experimental tests conducted using the proposed methodology for steel pipes having different types of structural complexity are described.

Underwater inspection of concrete-filled steel pipes using guided waves

2002 ◽  
Vol 6 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Won-Bae Na ◽  
Tribikram Kundu ◽  
Yeon-Sun Ryu
Keyword(s):  
Guided Waves ◽  
Steel Pipes

Scattering of Guided Waves by Circumferential Cracks in Steel Pipes

2000 ◽  
Vol 68 (4) ◽  
pp. 619-631 ◽  
Author(s):  
H. Bai ◽  
A. H. Shah ◽  
N. Popplewell ◽  
S. K. Datta
Keyword(s):  
Wave Scattering ◽  
Guided Waves ◽  
Crack Depth ◽  
Scattering Problem ◽  
Three Dimensional ◽  
Numerical Procedure ◽  
Axial Direction ◽  
Computational Time ◽  
Steel Pipes ◽  
Transmission Coefficients

A novel numerical procedure is presented in this paper to study wave scattering problem by circumferential cracks in steel pipes. The study is motivated by the need to develop a quantitative ultrasonic technique to characterize properties of cracks in pipes. By employing wave function expansion in axial direction and decomposing the problem into a symmetry problem and an antisymmetry problem, a three-dimensional wave scattering problem is then reduced into two quasi-one-dimensional problems. This simplification greatly reduces the computational time. Numerical results for reflection and transmission coefficients of different incident wave modes are presented here for a steel pipe with cracks (may have arbitrary circumferential crack length and radial crack depth) and they are shown to agree quite closely with available but limited experimental data.

EMAT-Based Inspection of Concrete-Filled Steel Pipes for Internal Voids and Inclusions

2002 ◽  
Vol 124 (3) ◽  
pp. 265-272 ◽  
Author(s):  
Won-Bae Na ◽  
Tribikram Kundu
Keyword(s):  
Guided Waves ◽  
Acoustic Method ◽  
Guided Wave ◽  
Long Distance ◽  
Steel Pipes ◽  
Acoustic Transducers ◽  
Bending Resistance ◽  
Good Potential ◽  
Internal Volume ◽  
Electro Magnetic

Concrete-filled steel pipes have been used as piles for supporting civil and marine structures. These piles provide good bending resistance, and can be easily spliced for long depth installation. However, these piles are usually exposed in hostile environments such as seawater and deicing materials. Thus, the outside corrosion of the steel pipe can reduce the wall thickness and the corrosion-induced delamination of internal concrete can increase internal volume or pressure. In addition, the void that can possibly exist in the pipe reduces the bending resistance. To avoid structural failure due to this type of deterioration, appropriate inspection and repair techniques are to be developed. The acoustic method is attractive for this inspection since it is relatively simple and versatile. Especially, guided wave techniques have strong potentials for this inspection because of long-distance inspection capability. There are different transducer-coupling mechanisms available for the guided wave inspection techniques. Electro-magnetic acoustic transducers (EMATs) give relatively consistent results in comparison to piezoelectric transducers since they do not need any couplant. EMATs are used for transmitting and receiving cylindrical guided waves through concrete-filled steel pipes. It is shown that EMAT-generated cylindrical guided wave techniques have good potential for the interface inspection of concrete-filled steel pipes.

Axisymmetric Guided Wave Scattering by Cracks in Welded Steel Pipes

1997 ◽  
Vol 119 (4) ◽  
pp. 401-406 ◽  
Author(s):  
W. Zhuang ◽  
A. H. Shah ◽  
S. K. Datta
Keyword(s):  
Wave Scattering ◽  
Guided Waves ◽  
Guided Wave ◽  
Numerical Results ◽  
Steel Pipe ◽  
Welded Steel ◽  
Cylindrical Structures ◽  
Steel Pipes ◽  
Cutoff Frequencies ◽  
Representation Techniques

Scattering of axisymmetric guided waves by cracks and weldments of anisotropic bonding material in welded steel pipes is investigated in this paper by a hybrid method employing finite element and modal representation techniques. The study is motivated by the need to develop a quantitative ultrasonic technique to distinguish flaws and bonding materials in welded cylindrical structures. Numerical results for reflection coefficients are presented for a steel pipe with cracks and V-shaped weldments with and without cracks at the interface between the weldment and the steel pipe. It is shown that as the frequency increases, the coefficients of reflection exhibit resonant peaks at the cutoff frequencies of higher guided modes. These peaks become increasingly pronounced as the slope and the length of the crack increase. Numerical results presented have important applications in quantitative nondestructive evaluation.

Tendencies of export and import of steel industry products of Russia within 9 months of 2019

2020 ◽  
Vol 76 (2) ◽  
pp. 107-112
Author(s):  
N. G. Zinov’eva
Keyword(s):  
Middle East ◽  
Steel Industry ◽  
Pig Iron ◽  
Finished Steel ◽  
Steel Pipes ◽  
Ferrous Metals ◽  
Steel Grades ◽  
Cis Countries ◽  
Further Development ◽  
Coated Sheet

Structure of the Russian export and import of steel industry products presented by results of 9 months of 2019 operation. It was shown, that the total share of pig iron, ferroalloys and semi-products (40.3%) in the ferrous metals export from Russia is practically the same as the share of rolled products and steel pipes (39.4%), whereas the shares in the import structure were 7.7 and 75% accordingly. The share the far abroad countries in the Russian export and import of finished steel products (in natural terms) accounted for 80.6 and 28.7% accordingly, while the share of CIS countries – 19.4 and 71.3% accordingly. For 9 months of 2019 the Russian export of semi-products declined by 10.9% comparing with the analogue period of 2018 and accounted for 10.9 m tons. 54.6% of the total export shipping of semi-products were directed to Mexico, Turkey, Egypt and Taiwan. Within the nearest years the Russian export of semi-products and billets, in particular, will be effected by the further development of the semi-products production in in the countries of Middle East, Turkey, Vietnam and India. The domestic market remained to be more attractive for many Russian companies. For the 9 months of 2019, export of long and flat products accounted for 3 and 5.7 m tons accordingly, declining comparing with the analogue period of the previous year by 11 and 15.6% accordingly. Import of long and flat products decreased by 12 and 0.5%, accounting for 1.0 and 2.9 m tons accordingly. By the results of 9 months of 2019, import declined and export shipping of coated sheet increased. Taking into account the expansion of steel grades assortment by Russian plants, increase of capacities for production of sheet with different coatings, this tendency is likely to remain.

Failure Analysis Of Buried Gas Pipelines Crossing Seismic Faults

2020 ◽  
Vol 3 (2) ◽  
pp. 781-790
Author(s):  
M. Rizwan Akram ◽  
Ali Yesilyurt ◽  
A.Can. Zulfikar ◽  
F. Göktepe
Keyword(s):  
Ground Deformation ◽  
Warning System ◽  
Strike Slip ◽  
Gas Pipelines ◽  
Steel Pipes ◽  
Seismic Fault ◽  
Fault Parameters ◽  
Dip Angle ◽  
Permanent Ground Deformation ◽  
Recent Earthquakes

Research on buried gas pipelines (BGPs) has taken an important consideration due to their failures in recent earthquakes. In permanent ground deformation (PGD) hazards, seismic faults are considered as one of the major causes of BGPs failure due to accumulation of impermissible tensile strains. In current research, four steel pipes such as X-42, X-52, X-60, and X-70 grades crossing through strike-slip, normal and reverse seismic faults have been investigated. Firstly, failure of BGPs due to change in soil-pipe parameters have been analyzed. Later, effects of seismic fault parameters such as change in dip angle and angle between pipe and fault plane are evaluated. Additionally, effects due to changing pipe class levels are also examined. The results of current study reveal that BGPs can resist until earthquake moment magnitude of 7.0 but fails above this limit under the assumed geotechnical properties of current study. In addition, strike-slip fault can trigger early damage in BGPs than normal and reverse faults. In the last stage, an early warning system is proposed based on the current procedure. 

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