This is our forklift test in Rigging Class. We had to maneuver an obstacle Course.
Tuesday, April 17, 2012
UT Phased Array during Meet and Greet Day
Phased array (PA) ultrasonics is an advanced method of ultrasonic testing that has applications in medical imaging and industrial nondestructive testing. Common applications are to examine the heart noninvasively or to find flaws in manufactured materials such as welds. Single-element (non phased array) probes—known technically as monolithic probes—emit a beam in a fixed direction. To test or interrogate a large volume of material, a conventional probe must generally be physically turned or moved to sweep the beam through the area of interest. In contrast the beam from a phased array probe can be moved electronically, without moving the probe, and can be swept through a wide volume of material at high speed. The beam is controllable because a phased array probe is made up of multiple small elements, each of which can be pulsed individually at a computer-calculated timing. The term phased refers to the timing, and the term array refers to the multiple elements. Phased array ultrasonic testing is based on principles of wave physics that also have applications in fields such as optics and electromagnetic antennae.
Eddy currents (also called Foucault currents[1]) are electric currents induced in conductors when a conductor is exposed to a changing magnetic field; due to relative motion of the field source and conductor or due to variations of the field with time. This can cause a circulating flow of electrons, or current, within the body of the conductor. These circulating eddies of current have inductance and thus induce magnetic fields. These fields can cause repulsive, attractive,[2] propulsion and drag effects. The stronger the applied magnetic field, or the greater the electrical conductivity of the conductor, or the faster the field changes, then the greater the currents that are developed and the greater the fields produced.
Monday, April 9, 2012
Electromagnetic Testing (ET)
Electromagnetic Testing (ET)
There are a number of electromagnetic testing methods but the focus here will be on eddy current testing. In eddy current testing, electrical currents (eddy currents) are generated in a conductive material by a changing magnetic field. The strength of these eddy currents can be measured. Material defects cause interruptions in the flow of the eddy currents which alert the inspector to the presence of a defect or other change in the material. Eddy currents are also affected by the electrical conductivity and magnetic permeability of a material, which makes it possible to sort some materials based on these properties. The technician in the image is inspecting an aircraft wing for defects.
There are a number of electromagnetic testing methods but the focus here will be on eddy current testing. In eddy current testing, electrical currents (eddy currents) are generated in a conductive material by a changing magnetic field. The strength of these eddy currents can be measured. Material defects cause interruptions in the flow of the eddy currents which alert the inspector to the presence of a defect or other change in the material. Eddy currents are also affected by the electrical conductivity and magnetic permeability of a material, which makes it possible to sort some materials based on these properties. The technician in the image is inspecting an aircraft wing for defects.
Penetrant Testing (PT)
Penetrant Testing (PT)
With this testing method, the test object is coated with a solution that contains a visible or fluorescent dye. Excess solution is then removed from the surface of the object but is left in surface breaking defects. A developer is then applied to draw the penetrant out of the defects. With fluorescent dyes, ultraviolet light is used to make the bleedout fluoresce brightly, thus allowing imperfections to be readily seen. With visible dyes, a vivid color contrast between the penetrant and developer makes the bleedout easy to see. The red indications in the image represent a defect in this component.
With this testing method, the test object is coated with a solution that contains a visible or fluorescent dye. Excess solution is then removed from the surface of the object but is left in surface breaking defects. A developer is then applied to draw the penetrant out of the defects. With fluorescent dyes, ultraviolet light is used to make the bleedout fluoresce brightly, thus allowing imperfections to be readily seen. With visible dyes, a vivid color contrast between the penetrant and developer makes the bleedout easy to see. The red indications in the image represent a defect in this component.
Ultrasonic Testing (UT)
Ultrasonic Testing (UT)
In ultrasonic testing, high-frequency sound waves are transmitted into a material to detect imperfections or to locate changes in material properties. The most commonly used ultrasonic testing technique is pulse echo, whereby sound is introduced into a test object and reflections (echoes) from internal imperfections or the part's geometrical surfaces are returned to a receiver. Below is an example of shear wave weld inspection. Notice the indication extending to the upper limits of the screen. This indication is produced by sound reflected from a defect within the weld.
In ultrasonic testing, high-frequency sound waves are transmitted into a material to detect imperfections or to locate changes in material properties. The most commonly used ultrasonic testing technique is pulse echo, whereby sound is introduced into a test object and reflections (echoes) from internal imperfections or the part's geometrical surfaces are returned to a receiver. Below is an example of shear wave weld inspection. Notice the indication extending to the upper limits of the screen. This indication is produced by sound reflected from a defect within the weld. Magnetic Particle Testing (MT)
Magnetic Particle Testing (MT)
This NDT method is accomplished by inducing a magnetic field in a ferromagnetic material and then dusting the surface with iron particles (either dry or suspended in liquid). Surface and near-surface flaws disrupt the flow of the magnetic field within the part and force some of the field to leak out at the surface. Iron particles are attracted and concentrated at sites of the magnetic flux leakages. This produces a visible indication of defect on the surface of the material. The images above demonstrate a component before and after inspection using dry magnetic particles.
This NDT method is accomplished by inducing a magnetic field in a ferromagnetic material and then dusting the surface with iron particles (either dry or suspended in liquid). Surface and near-surface flaws disrupt the flow of the magnetic field within the part and force some of the field to leak out at the surface. Iron particles are attracted and concentrated at sites of the magnetic flux leakages. This produces a visible indication of defect on the surface of the material. The images above demonstrate a component before and after inspection using dry magnetic particles.
Radiography (RT)
Radiography (RT)
RT involves using penetrating gamma- or X-radiation on materials and products to look for defects or examine internal or hidden features. An X-ray generator or radioactive isotope is used as the source of radiation. Radiation is directed through a part and onto film or other detector. The resulting shadowgraph shows the internal features and soundness of the part. Material thickness and density changes are indicated as lighter or darker areas on the film or detector. The darker areas in the radiograph below represent internal voids in the component.
RT involves using penetrating gamma- or X-radiation on materials and products to look for defects or examine internal or hidden features. An X-ray generator or radioactive isotope is used as the source of radiation. Radiation is directed through a part and onto film or other detector. The resulting shadowgraph shows the internal features and soundness of the part. Material thickness and density changes are indicated as lighter or darker areas on the film or detector. The darker areas in the radiograph below represent internal voids in the component.
Visual and Optical Testing (VT)
Visual and Optical Testing (VT)
The most basic NDT method is visual examination. Visual examiners follow procedures that range from simply looking at a part to see if surface imperfections are visible, to using computer controlled camera systems to automatically recognize and measure features of a component.
The most basic NDT method is visual examination. Visual examiners follow procedures that range from simply looking at a part to see if surface imperfections are visible, to using computer controlled camera systems to automatically recognize and measure features of a component.
Liquid Penetrant Testing
Dye penetrant inspection (DPI), also known as liquid penetrant examination (LPE), is a type of non-destructive testing used generally in the detection of surface flaws in non-ferrous alloys. The dye penetrant inspection (DPI) method employs a penetrating liquid, applied to the surface of the component and enters the flaw, crack or seam. After the excess penetrant has been cleared from the surface, the penetrant is drawn back out and the crack is observed using a white light or UV light. Dye penetrant inspection (DPI) can also be used for the inspection of ferrous materials where magnetic particle inspection is difficult to apply. In some cases Dye penetrant inspection (DPI) can be used on non-metallic materials. Variations include the use of fluorescent dyes, where a black (UV) light is used to illuminate the residual penetrant. This Dye penetrant inspection (DPI) technique has even higher sensitivity than normal LPE but can only be used in the absence of other light sources.
Dye penetrant inpection can be applied to any non-porous clean material, metallic or non-metallic material, but is unsuitable for dirty or rough surfaces.
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