The Development of a 2D Ultrasonic Array Inspection for Single Crystal Turbine Blades PDF Download

Author: Christopher Lane
Publisher: Springer Science & Business Media
ISBN: 3319025171
Category : Technology & Engineering
Languages : en
Pages : 141

View

Book Description
This thesis describes the development of a new technique to solve an important industrial inspection requirement for a high-value jet-engine component. The work – and the story told in the thesis – stretches all the way from the fundamentals of wave propagation in anisotropic material and ultrasonic array imaging through to device production and site trials. The book includes a description of a new method to determine crystallographic orientation from 2D ultrasonic array data. Another new method is described that enables volumetric images of an anisotropic material to be generated from 2D ultrasonic array data, based on measured crystallographic orientation. After extensive modeling, a suitable 2D array and deployment fixtures were manufactured and tested on in situ turbine blades in real engines. The final site trial indicated an order of magnitude improvement over the best existing technique in the detectability of a certain type of root cracking. The Development of a 2D Ultrasonic Array Inspection for Single Crystal Turbine Blades should be an inspiration for those starting out on doctoral degrees as it shows the complete development cycle from basic science to industrial usage.

Author: Christopher John Leslie Lane
Publisher:
ISBN:
Category :
Languages : en
Pages : 153

View

Book Description

Author: Chunguang Xu
Publisher: CRC Press
ISBN: 1040051804
Category : Technology & Engineering
Languages : en
Pages : 476

View

Book Description
Focusing on the theory and state-of-the-art technologies of ultrasonic testing (UT), this book examines ultrasonic propagation in solids and its detection applications, and explores the intersection of UT technology with various fields of electromagnetics, optics and physics. UT is one of the most widely used nondestructive testing techniques due to its high performance in terms of detection efficiency and safety. The rapid development of modern industrial products and technologies has created a new challenge and demand for ultrasonic nondestructive testing technology. This book introduces the fundamentals of UT, including sound wave and sound field, interface wave theory and liquid-solid coupled sound field. It then discusses various types of UT methods, ranging from the critically refracted longitudinal wave method to ultrasonic surface wave and ultrasonic guided wave detection methods. Some newly developed UT techniques are also discussed, including phased-array UT, high-frequency UT and non-contact UT. This title will appeal to engineering students and technicians in the field of ultrasonic nondestructive testing.

Author: Robert Hanus
Publisher: Springer
ISBN: 3030111873
Category : Technology & Engineering
Languages : en
Pages : 424

View

Book Description
This book discusses selected issues of modern electrical metrology in the fields of sensor technology, signal processing and measurement systems, addressing theoretical problems and applications regarding measurements in electrical engineering, mechanics, telecommunications, medicine and geology, as well as in the aviation and transport industries. It presents selected papers from the XXII International Seminar of Metrology “Methods and Techniques of Signal Processing in Physical Measurements” (MSM2018) held in Rzeszów-Arłamów, Poland on September 17–20, 2018. The conference was organized by the Rzeszow University of Technology, Department of Metrology and Diagnostic Systems (Poland) and Lviv Polytechnic National University, Department of Information Measuring Technology (Ukraine). The book provides researchers and practitioners with insights into the state of the art in these areas, and also serves as a source of new ideas for further development and cooperation.

Author: Chris Charlesworth (Eng.D.)
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
The thesis presented herein comprises of the work undertaken to research novel methods of Phased array ultrasonic inspection of complex steam turbine blade roots as found in the power generation industry. The research was conducted as part of the Engineering Doctorate scheme, administered by the Research Centre for Non-Destructive Evaluation (RCNDE), in conjunction with RWE npower and the University of Warwick. Steam turbine blades, and in particularly last stage blades of low pressure steam turbines, are amongst the most highly stressed components on a power generating plant. Two of the most common blade root fixing types include 'curved axial entry fir tree roots' (CAEFTR), and axial pinned roots, both of which are prone to cracking due to the high stresses to which they are subjected under operating conditions. Failure of the blade root fixings of such components, leading to the release of the blades, has historically led to the catastrophic failure and destruction of the whole turbine; the cost of collateral damage to plant components and the loss in generating income are seconded only by the risk these failures pose to life. Due to the high price of failure, NDT plays a critical part in the support and management of engineering maintenance, offering insight into the condition and integrity of turbine components through regular planned inspection regimes. It will be shown in this thesis how the invention of a novel continuous wedge, used to refract ultrasound into the critical regions of the blade roots, has significantly improved the ability to detect defects. Combined with the development of bespoke scanning frames these wedges facilitate the efficient and accurate acquisition of scanned data to assess the integrity of the component. By combining the latest reverse engineering, modelling and simulation tools with novel application of rapid prototyping, the author has been able to demonstrate significant reduction in design cycles whilst improving accuracy, sensitivity and repeatability of the applied inspections. Furthermore, application of this design philosophy has led to the development of inspection techniques which have facilitated the inspection of remote regions of the blade roots where manual access is limited or impossible. The developments and techniques invented during this research have been successfully deployed across numerous RWE npower and customer projects, leading to estimated savings in excess of £1m.

Author: Mark V. Brook
Publisher: John Wiley & Sons
ISBN: 111810479X
Category : Technology & Engineering
Languages : en
Pages : 322

View

Book Description
Ultrasonic testing is a relatively new branch of science and industry. The development of ultrasonic testing started in the late 1920s. At the beginning, the fundamentals of this method were borrowed from basic physics, geometrical and wave optics, acoustics and seismology. Later it became clear that some of these theories and calculation methods could not always explain the phenomena observed in many specific cases of ultrasonic testing. Without knowing the nuances of the ultrasonic wave propagation in the test object it is impossible to design effective inspection technique and search units for it realization. This book clarifies the theoretical differences of ultrasonics from the other wave propagation theories presenting both basics of physics in the wave propagation, elementary mathematic and advanced practical applications. Almost every specific technique presented in this book is proofed by actual experimental data and examples of calculations.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 7

View

Book Description

Author: Jerzy Dziewierz
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description
Ultrasonic inspection can be considered as one of many ways the technical system - installation or vehicle - can be made economical and safe. Contemporary ultrasonic systems are capable of detecting a wide variety of mechanical defects and flaws that may or may not affect the operation of a given product. Ultrasonic testing techniques are widely accepted for quality control and material testing. Moreover, the technology is proven, well-understood and widely used. Upon detecting a flaw, a decision has to be made to ensure the component is fit for the purpose: is the flaw acceptable or is repair of the given part or its replacement? Here, 2D ultrasonic phased arrays hold promise to quickly deliver detailed, 3D resolved information about the extent and nature of the flaw. This information can then be used to develop and justify the technical and economic decision concerning the existing state of the product. In effect, an opportunity exists for significant cost savings by using ultrasonic 2D phased array systems for defect characterisation. The interest of the work is to establish a process of designing and manufacturing of piezoelectric, 2D phased array ultrasound probes for application in non-destructive evaluation of materials. Furthermore, implementation of practical signal processing method is investigated. In the first part of the work the sensor mechanical and electrical design is addressed. The properties of piezoelectric ceramic composite materials are studied. Detailed numerical models have been used to analyse conditions required for crafting materials of desirable properties. A novel technique has been demonstrated that allows design of well-behaved triangular cut piezoelectric composite. Built into a single array element (of hexagonal shape by taking 6 triangular pillars) this new composite exhibits properties comparable to a reference rectangular composite (sensitivity of 0.60nm/V for hexagonal, 0.62nm/V for square; and inter-element crosstalk of -21.2dB for hexagonal and -21.9dB for square element). This composite then allows building of compact, dense-layout 2D phased array transducers with hexagonal or sparse element layout. The benefits of hexagonal element layout over classic, rectangular layout have been analysed theoretically and showed to be beneficial. Importantly, using hexagonal elements enables increasing the aperture of individual array elements by approximately 10% without the corresponding drop in acceptance angle. This in turn allows a commensurable rise in the sensitivity of the sensor or alternatively, reduction in array element count for a given overall array aperture by over 20% without the corresponding drop in the image quality measurements/levels. In the second part of the work, the problem of high output impedance of the miniature ultrasonic sensor is addressed by means of an in-probe miniature signal conditioning circuit. This improved the response amplitude of the element by 36dB and shortened its impulse response by a factor of 1.6. The novelty and practical benefit in this case lies in the fact that no high power components are needed in the probe body. In the third part of this work, an emerging General-Purpose Graphics Processing Unit (GPGPU) computer architecture is considered for the opportunities it offers to rethink the implementation of algorithms typically used in ultrasonic signal processing. Single-way beamforming, and two-way TFM and PCF beamforming have been developed for execution on the new platform, and show increase in performance of over 930 times compared to CPU processor. This software platform has been further enhanced by a new approach to solving the refracted ray Time of Flight problem in a way that is particularly well suited for this architecture. This resulted in a further increase of performance, i.e. 56x over the best published result found in the literature. The unprecedented performance and low cost of this new approach enables industrial deployment of advanced beamforming methods, as well as building of practical CAD tools for engineering and education.

Author: Timothy Lardner
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description
The push for more efficient operation of power generation stations has led to the development of advanced alloys designed to cope with the stresses of running at elevated temperatures. The micro-structure of these new alloys makes the inspection process difficult due to large grains that scatter ultrasonic energy. Aerospace components such as aircraft engine turbine blades are made from similar materials and pose the same difficulties for inspection. In addition, the complex geometries of many of these parts hinder the use of existing advanced imaging methodologies. The current inspection process involves using both individual transducers and phased arrays to collect pulse-echo data from structures.This process is not sufficient for such difficult materials and a new process must be devised, tested and deployed. This thesis presents an investigation of new practical techniques to process ultrasonic array data collected via a Full Matrix Capture.Two novel signal processing techniques are presented, evaluated and compared to the Total Focusing Method, which is currently considered as the gold standard in ultrasonic array processing. A study into efficient imaging has also been completed, which involved development of an algorithm to focus upon any point through an arbitrary refracting interface. This algorithm was implemented on a commercially available graphics card and is able to account for a curved interface in real time with no prior knowledge of the surface profile.Spatially Averaged Sub-Aperture Correlation Imaging splits the full matrix of data into a set of sub-apertures which are imaged independently from each other. These images are then combined into two sets and are input to a two-dimensional cross-correlation algorithm that outputs a weighting matrix that can be applied to the sum of all images. Signals that are from legitimate reectors are highly correlated while less-correlated indications are the result of noise from scattering and multi-path propagation. SASACI has been shown to perform well experimentally through inspection of defects within multiple highly scattering welds at a frequency of 5 MHz.Correlation for Adaptively Focused Imaging aims to correct for anisotropy within difficult materials. The longitudinal velocity within a difficult material can vary with position and using an average velocity does not guarantee a well-focused image. For each pixel in an image,CAFI calculates which samples will be used to calculate the amplitude of the pixel before cross-correlating the signals from adjacent array elements and shifting the delay to the point of maximum focus. This methodology is effective when a small area with a known reflector is being imaged, and for this reason the algorithm is suited to characterisation of reflectors. This technique was experimentally validated on a block of Inconel 625 with a number of side-drilled holes.

Author: N. A. Cumpsty
Publisher: Cambridge University Press
ISBN: 9780521541442
Category : Technology & Engineering
Languages : en
Pages : 326

View

Book Description
This is the second edition of Cumpsty's excellent self-contained introduction to the aerodynamic and thermodynamic design of modern civil and military jet engines. Through two engine design projects, first for a new large passenger aircraft, and second for a new fighter aircraft, the text introduces, illustrates and explains the important facets of modern engine design. Individual sections cover aircraft requirements and aerodynamics, principles of gas turbines and jet engines, elementary compressible fluid mechanics, bypass ratio selection, scaling and dimensional analysis, turbine and compressor design and characteristics, design optimization, and off-design performance. The book emphasises principles and ideas, with simplification and approximation used where this helps understanding. This edition has been thoroughly updated and revised, and includes a new appendix on noise control and an expanded treatment of combustion emissions. Suitable for student courses in aircraft propulsion, but also an invaluable reference for engineers in the engine and airframe industry.