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Understanding Acoustic Emission Testing- Reading 2015-1A
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Understanding Acoustic Emission Testing, AET- R eading 1 My Pre-exam ASNT Self Study Notes 3rd September 2015 Charlie Chong/ Fion Zhang
E&P Applications Charlie Chong/ Fion Zhang
Concrete Offshore structure Charlie Chong/ Fion Zhang
Wind Energy Offshore structure Charlie Chong/ Fion Zhang
Refinery Applications Charlie Chong/ Fion Zhang
Refinery Applications http://wins-ndt.com/oil-chem/spherical-tanks/ Charlie Chong/ Fion Zhang
http://www.smt.sandvik.com/en/search/?q=stress+corrosion+crackinghttp://www.smt.sandvik.com/en/search/?q=stress+corrosion+cracking Charlie Chong/ Fion Zhang
The Magical Book of Acoustic Emission Charlie Chong/ Fion Zhang
数字签名者:Fion Zhang DN:cn=Fion Zhang, o=Technical, ou=Academic, email=fion_zhang@ qq.com, c=CN 日期:2016.07.18 14:18:02 +08'00' Charlie Chong/ Fion Zhang
ASNT Certification Guide NDT Level III / PdM Level III AE - Acoustic Emission Testing Length: 4 hours Questions: 135 1 Principles and Theory • Characteristics of acoustic emission testing • Materials and deformation • Sources of acoustic emission • Wave propagation • Attenuation • Kaiser and Felicity effects, and Felicity ratio • Terminology (refer to acoustic emission glossary, ASTM 1316) Charlie Chong/ Fion Zhang
2 Equipment and Materials • Signal conditioning • Transducing processes • Signal detection • Sensors • Signal processing • Sensor attachments • Source location • Sensor utilization • Advanced signal processing • Simulated acoustic emission sources • Acoustic emission test systems • Cables • Accessory materials • Factors affecting test equipment selection Charlie Chong/ Fion Zhang
3 Techniques 4 Interpretation and Evaluation • Equipment calibration and set up for • Data interpretation test • Data evaluation • Establishing loading procedures • Reports • Precautions against noise 5 Procedures • Special test procedures 6 Safety and Health • Data displays 7 Applications • Laboratory studies (material- characterization) • Structural applications Charlie Chong/ Fion Zhang
Reference Catalog Number NDT Handbook, Second Edition: Volume 5, Acoustic Emission Testing 130 Acoustic Emission: Techniques and Applications 752 Charlie Chong/ Fion Zhang
Fion Zhang at Shanghai 3rd September 2015 Charlie Chong/ Fion Zhang http://meilishouxihu.blog.163.com/
Greek Alphabet Charlie Chong/ Fion Zhang
Charlie Chong/ Fion Zhang http://greekhouseoffonts.com/
Video on - Leak Detection on Buried Water Piping using Acoustic Emission ■ https://www.youtube.com/watch?v=9kq6JxIJDik Charlie Chong/ Fion Zhang
Contents: AE Codes and Standards ■ ASTM ■ ASME V 1. Reading 01- www.geocities.ws/raobpc/AET.html 2. Reading 02- Sidney Mindess University of British Columbia Chapter 16: Acoustic Emission Methods 3. Reading 03- AET ndt-ed.org 4. Reading 04- Terms & Definitions ASTM E1316 5. Reading 05- Q&A 25 items 6. Reading 06- High Strength Steel- TWIP Steel 7. Reading 07- AET- optimum solution for leakage detection of water pipeline 8. Others reading. Charlie Chong/ Fion Zhang
ASME V Article Numbers: Gen RT Nil UT UT PT MT ET Visual Article 9 LT Article 10 AE Article 11 (FRP) AE Article 12 (Metallic) AE Article 13 (Continuous) Qualif. Article 14 ACFM Article 15 Article 1 Article 2 Article 3 Article 4 for welds Article 5 for materials Article 6 Article 7 Article 8 Charlie Chong/ Fion Zhang
ASTM Standards E569 - 07 Standard Practice for Acoustic Emission Monitoring of Structures During Controlled Stimulation E650 – 97 (2007) Standard Guide for Mounting Piezoelectric Acoustic Emission Sensors E749 - 07 Standard Practice for Acoustic Emission Monitoring During Continuous Welding E750 - 04 Standard Practice for Characterizing Acoustic Emission Instrumentation E751 - 07 Standard Practice for Acoustic Emission Monitoring During Resistance Spot-Welding Charlie Chong/ Fion Zhang
ASTM Standards E976 - 05 Standard Guide for Determining the Reproducibility of Acoustic Emission Sensor Response E1067 - 07 Standard Practice for Acoustic Emission Examination of Fiberglass Reinforced Plastic Resin (FRP) Tanks/Vessels E1106 - 07 Standard Test Method for Primary Calibration of Acoustic Emission Sensors E1118 - 05 Standard Practice for Acoustic Emission Examination of Reinforced Thermosetting Resin Pipe (RTRP) E1139 - 07 Standard Practice for Continuous Monitoring of Acoustic Emission from Metal Pressure Boundaries Charlie Chong/ Fion Zhang
ASTM Standards E1211 - 07 Standard Practice for Leak Detection and Location Using Surface- Mounted Acoustic Emission Sensors E1419 - 09 Standard Practice for Examination of Seamless, Gas-Filled, Pressure Vessels Using Acoustic Emission E1495 - 02 (2007) Standard Guide for Acousto-Ultrasonic Assessment of Composites, Laminates, and Bonded Joints E1736 - 05 Standard Practice for Acousto-Ultrasonic Assessment of Filament- Wound Pressure Vessels Charlie Chong/ Fion Zhang
ASTM Standards E1781 - 08 Standard Practice for Secondary Calibration of Acoustic Emission Sensors E1888 /E1888M – 07 Standard Practice for Acoustic Emission Examination of Pressurized Containers Made of Fiberglass Reinforced Plastic with Balsa Wood Cores E1930 – 07 Standard Practice for Examination of Liquid-Filled Atmospheric and Low-Pressure Metal Storage Tanks Using Acoustic Emission E1932 - 07 Standard Guide for Acoustic Emission Examination of Small Parts E2075 – 05 Standard Practice for Verifying the Consistency of AE-Sensor Response Using an Acrylic Rod Charlie Chong/ Fion Zhang
ASTM Standards E2076 - 05 Standard Test Method for Examination of Fiberglass Reinforced Plastic Fan Blades Using Acoustic Emission E2191 - 08 Standard Practice for Examination of Gas-Filled Filament-Wound Composite Pressure Vessels Using Acoustic Emission E2374 - 04 Standard Guide for Acoustic Emission System Performance Verification E2478 - 06a Standard Practice for Determining Damage-Based Design Stress for Fiberglass Reinforced Plastic (FRP) Materials Using Acoustic Emission E2598 - 07 Standard Practice for Acoustic Emission Examination of Cast Iron Yankee and Steam Heated Paper Dryers Charlie Chong/ Fion Zhang
Typical AET Signal https://dspace.lib.cranfield.ac.uk/bitstream/1826/2196/1/Acoustic%20Emission%20Waveform%20Changes%202006.pdf Charlie Chong/ Fion Zhang
Typical AET Signal Charlie Chong/ Fion Zhang
Study Note 1: AET http://www.geocities.ws/raobpc/AET.html http://www.geocities.ws/raobpc/AET.html Charlie Chong/ Fion Zhang
What is AE Acoustic emission is the technical term for the noise emitted by materials and structures when they are subjected to stress. Types of stresses can be (1) mechanical, (2) thermal or (3) chemical. This emission is caused by the rapid release of energy within a material due to events such as crack initiation and growth, crack opening and closure, dislocation movement, twinning, and phase transformation in monolithic materials and fiber breakage and fiber- matrix debonding in composites. The subsequent extension occurring under an applied stress generates transient elastic waves which propagate through the solid to the surface where they can be detected by one or more sensors. The sensor is a transducer that converts the mechanical wave into an electrical signal (piezoelectric) . In this way information about the existence and location (triangulation by multi-transducers) of possible sources is obtained. Acoustic emission may be described as the "sound" emanating from regions of localized deformation within a material. http://www.geocities.ws/raobpc/AET.html Charlie Chong/ Fion Zhang
Until about 1973, acoustic emission technology was primarily employed in the non-destructive testing of such structures as pipelines, heat exchangers, storage tanks, pressure vessels, and coolant circuits of nuclear reactor plants. However, this technique was soon applied to the detection of defects in rotating equipment bearings. Applications: Static subjects Dynamic subjects http://www.geocities.ws/raobpc/AET.html Charlie Chong/ Fion Zhang
http://www.geocities.ws/raobpc/AET.html Charlie Chong/ Fion Zhang
http://www.geocities.ws/raobpc/AET.html Charlie Chong/ Fion Zhang
Acoustic Emission Acoustic Emission (AE) refers to generation of transient elastic waves 瞬间弹 性波 during rapid release of energy from localized sources within a material. The source of these emissions in metals is closely associated with the dislocation movement accompanying plastic deformation and with the initiation and extension of cracks in a structure under stress. 应力作用下, 结 构中的裂纹萌生/扩展(塑性变形)造成的位错运动.这位错运动会引发瞬间的弹 性波. Other sources of AE are: melting, phase transformation, thermal stresses, cool down cracking and stress build up, twinning, fiber breakage and fiber- matrix debonding in composites. 其他会引起瞬间的弹性波 的因素: 熔化,相变,热应力冷却裂纹和应力建立,孪晶,在复合材料中的纤维断裂和纤 维-基体界面脱粘 http://www.geocities.ws/raobpc/AET.html Charlie Chong/ Fion Zhang
AE Technique The AE technique (AET) is based on the detection and conversion of high frequency elastic waves emanating from the source to electrical signals. This is accomplished by directly coupling piezoelectric transducers on the surface of the structure under test and loading the structure. The output of the piezoelectric sensors (during stimulus) is amplified through a low-noise preamplifier, filtered to remove any extraneous noise and further processed by suitable electronics. AET can non-destructively predict early failure of structures. Further, a whole structure can be monitored from a few locations and while the structure is in operation. AET is widely used in industries for detection of faults or leakage in pressure vessels, tanks, and piping systems and also for on-line monitoring welding and corrosion. The difference between AET and other non-destructive testing (NDT) techniques is that AET detects activities inside materials, while other techniques attempt to examine the internal structures of materials by sending and receiving some form of energy. http://www.geocities.ws/raobpc/AET.html Charlie Chong/ Fion Zhang
Types of AET Acoustic emissions are broadly classified into two major types namely; continuous type (associated with lattice dislocation) burst type. (twinning, micro yielding, development of crack) The waveform of continuous type AE signal is similar to Gaussian random noise, but the amplitude varies with acoustic emission activity. In metals and alloys, this form of emission is considered to be associated with the motion of dislocations. Burst type emissions are short duration pulses and are associated with discrete release of high amplitude strain energy. In metals, the burst type emissions are generated by twinning, micro yielding, development of cracks. Continuos type (Gaussian random noise) → Motion of dislocation, Burst type (discrete high amplitude strain energy) → twinning, micro yielding, development of cracks http://www.geocities.ws/raobpc/AET.html Charlie Chong/ Fion Zhang
What is Normal (Gaussian) distribution In probability theory, the normal (or Gaussian) distribution is a very common continuous probability distribution. Normal distributions are important in statistics and are often used in the natural and social sciences to represent real-valued random variables whose distributions are not known.[1][2] The normal distribution is remarkably useful because of the central limit theorem. In its most general form, under mild conditions, it states that averages of random variables independently drawn from independent distributions are normally distributed. Physical quantities that are expected to be the sum of many independent processes (such as measurement errors) often have distributions that are nearly normal.[3] Moreover, many results and methods (such as propagation of uncertainty and least squares parameter fitting) can be derived analytically in explicit form when the relevant variables are normally distributed. Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Normal_distribution
The normal distribution is sometimes informally called the bell curve. However, many other distributions are bell-shaped (such as Cauchy's, Student's, and logistic). The terms Gaussian function and Gaussian bell curve are also ambiguous because they sometimes refer to multiples of the normal distribution that cannot be directly interpreted in terms of probabilities. The probability density of the normal distribution is: Hereμ is the mean or expectation of the distribution (and also its median and mode). The parameter σ is its standard deviation with its variance then σ2. A random variable with a Gaussian distribution is said to be normally distributed and is called a normal deviate. If μ = 0 and σ = 1, the distribution is called the standard normal distribution or the unit normal distribution denoted by N(0,1) and a random variable with that distribution is a standard normal deviate. Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Normal_distribution
Probability density function for the normal distribution Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Normal_distribution
Cumulative distribution function of an acoustic emission Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Normal_distribution
Cumulative distribution function of an acoustic emission Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Normal_distribution
Discussion Subject: What is the difference between an Gaussian random noise and an engineering acoustic emission? Answer: The waveform of continuous type AE signal is similar to Gaussian random noise, but the amplitude varies with acoustic emission activity. Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Normal_distribution
Crystal Twinning Crystal twinning occurs when two separate crystals share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals in a variety of specific configurations. A twin boundary or composition surface separates the two crystals. Crystallographers classify twinned crystals by a number of twin laws. These twin laws are specific to the crystal system. The type of twinning can be a diagnostic tool in mineral identification. Twinning can often be a problem in X-ray crystallography, as a twinned crystal does not produce a simple diffraction pattern. Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Crystal_twinning
Twin boundaries occur when two crystals of the same type intergrow, so that only a slight misorientation exists between them. It is a highly symmetrical interface, often with one crystal the mirror image of the other; also, atoms are shared by the two crystals at regular intervals. This is also a much lower- energy interface than the grain boundaries that form when crystals of arbitrary orientation grow together. Twin boundaries are partly responsible for shock hardening and for many of the changes that occur in cold work of metals with limited slip systems or at very low temperatures. They also occur due to martensitic transformations: the motion of twin boundaries is responsible for the pseudoelastic and shape- memory behavior of nitinol, and their presence is partly responsible for the hardness due to quenching of steel. In certain types of high strength steels, very fine deformation twins act as primary obstacles against dislocation motion. These steels are referred to as 'TWIP' steels, where TWIP stands for TWinning Induced Plasticity Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Crystal_twinning
What is Crystal Twinning Crystal twinning occurs when two separate crystals share some of the same crystal lattice points in a symmetrical manner. Crystal-A Crystal-B Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Crystal_twinning
Crystal Twinning Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Crystal_twinning
Crystal Twinning Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Crystal_twinning
Fivefold twinning in a gold nano-particle (electron microscope image). Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Crystal_twinning
Crystal Twinning- Diagram of twinned crystals of Albite. On the more perfect cleavage, which is parallel to the basal plane (P), is a system of fine striations, parallel to the second cleavage (M). Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Crystal_twinning
Crystal Twinning- Martensitic Formation Charlie Chong/ Fion Zhang https://en.wikipedia.org/wiki/Crystal_twinning