Abstract: An extensometer support system having vibration damping mountings for parts that have substantial mass and which are subjected to external vibrations. Such parts include counterweights for counterbalancing the extensometer and also the mounting for an external support frame for the extensometer. The vibration damping comprises a mounting made of a suitable damping material, such as a silicone foam rubber.

Abstract: An apparatus for use in determining a thermal characteristic of a specimen includes first and second chucks for engaging two regions of the specimen, a first chuck mounting mechanism for supporting the first chuck in relatively fixed orientation, and a second chuck mounting mechanism. The second chuck mounting mechanism supports the second chuck in relatively movable orientation relative to the first chuck to permit variations in the spacing between the first and second chucks occasioned by thermal variations in the specimen. A base supports the first and second chuck mounting mechanisms. A laser is provided for heating a third region of the specimen lying between the two regions to a different temperature than the two regions. An infrared detector is provided for detecting radiation emitted from the third region.

Abstract: A test specimen is provided, that is constructed of dual materials, which are preferably metallic materials and which are more preferably an austenitic iron alloy and a ferritic iron alloy. The specimen is generally constructed as a rectangular configuration, with two principal legs, connected together by substantially rigid connections at their ends, with the legs being of the different materials, such that, when the specimen is subjected to heat, one leg will expand linearly an amount greater than the other leg allowing the imposition of bending stress, whereby a given leg will experience both tension and compression. Observation may then be made, by a microscopic examination or otherwise, of those surfaces that are adjacent the portions of the legs that experience most of the tension and compression, such that the effects of temperature on the materials may be observed and recorded.

Abstract: A method and apparatus for simulating operational demands acting an expanded tube joints includes penetrating a central inner region of a circular disc of a test body with a plurality of hollow cylinders. Sleeves or hollow plugs are connected to the hollow cylinders in the vicinity of the disc. A stress condition is created in the inner region corresponding to the operational demands by applying a force in an outer region of the disc through a uniform introduction of heat in the outer region while cooling the inner region. Outer hollow cylinders may serve as cooling passages and may form a boundary between the inner region and the outer region. Thermal insulation may be associated with the outer region. An electric resistance heater may be associated with the outer region for applying the force.

Abstract: Low temperature dilatometers are described which employ a combination cryostat/furnace made from an elongated block of metal by drilling separate longitudinal tubular chambers for insertion of a specimen tube containing a specimen and at least one electric resistance heater. A separate longitudinally drilled tubular cooling chamber serves as the expansion chamber for a conventional compressed gas refrigeration system, one end of the cooling chamber communicating with the inlet of the refrigerant gas compressor and the other end communicating, through an intermediate heat exchanger, with the outlet of the compressor. The metal construction of the cryostat/furnace and the absence of a conventional ceramic protection tube for the specimen facilitates rapid heat transfer to and from the specimen. The specimen can be brought quickly to the minimum desired temperature by operating the refrigeration system until that temperature is reached and then shutting off the compressor.

Abstract: A method for the detection of delaminated areas in coated materials or layered composites, which allows free-air operation and can be used to scan portions of bulky materials on the spot. This method which makes it possible to detect very small delaminated areas in a very short time (less than 1 millisecond), with a very high sensitivity and without creation of excessive thermal stress in the inspected material, basically comprises the steps of: focusing pulsed, thermal radiations onto the structure to be inspected to produce a vertical displacement of its coating by thermal expansion if a delaminated area is present at the coating-to-substrate interface, and detecting and measuring this vertical displacement if any, by interferometry, preferably laser-beam interferometry. An apparatus for carrying out this method is also disclosed.

Abstract: An apparatus for automatic measuring thermal dimensional change from the room temperature to 2,000.degree. C., comprising, (a) means for supporting a specimen of the material to be tested and heating said specimen, (b) means for measuring the dimensional change of the specimen during heating said specimen, said measuring means having photo diode linear array and the telescopic lens for forming an image of the heated specimen, (c) means for illuminating the specimen from the opposite side of the photo diode linear array, said means having electric lamp and condensor lens, the radiation characteristic curve of said lamp being different from that of heated specimen, (d) means for separating the light forming image from the light radiated from said heated specimen, said means having light filter and neutral density filter between said specimen and said optical lens, (e) means for processing and calculating the video signal from the photo diode linear array indicating the results of measurements.

Abstract: Low temperature dilatometers are described which employ a combination cryostat/furnace made from an elongated block of metal by drilling separate longitudinal tubular chambers for insertion of a specimen tube containing a specimen and at least one electric resistance heater. A separate longitudinally drilled tubular cooling chamber serves as the expansion chamber for a conventional compressed gas refrigeration system, one end of the cooling chamber communicating with the inlet of the refrigerant gas compressor and the other end communicating, through an intermediate heat exchanger, with the outlet of the compressor. The metal construction of the cryostat/furnace and the absence of a conventional ceramic protection tube for the specimen facilitates rapid heat transfer to and from the specimen. The specimen can be brought quickly to the minimum desired temperature by operating the refrigeration system until that temperature is reached and then shutting off the compressor.

Abstract: Dilatometers in which the dilation sensor, pushrod or rods and the specimen holder all are enclosed within a unitary hermetically sealed housing, including an elongated protective tube for the portion of the specimen holder that is inserted in an electric tube furnace. The housing, which is compact and can be evacuated and flushed with an inert or reducing gas to protect its contents from oxidation, can easily and quickly be withdrawn as a unit from a stationary or unopened furnace to facilitate the rapid installation of similar housings having specialized sensors or tubular enclosures designed for different applications. The sensor, push rod and specimen holder also can be readily removed as a unit from the housing, which permits rapid specimen changes without the necessity of withdrawing the protective tube from the furnace or realigning it after reinsertion. A dilation sensor also is described which utilizes a calibrating micrometer positioned abreast of a linear variable differential transformer.

Abstract: Equipment for investigating crack propagation in thick steel plates of a material with applicability for pressure vessels comprises a test specimen in the form of a hollow cylinder of the material under investigation, a vertical spindle from which the hollow cylinder is suspended and which can be rotated at a speed of the order of thousands of revolutions per minute, damping means for damping against flexural resonance vibrations of the cylinder and spindle, a container for the cylinder and means for supplying hot air to the container via a port, means for applying through a port in the container, a jet of cold fluid on to a surface of the cylinder to apply thermal shock thereto the spindle being hollow to accommodate leads from instrumentation on the cylinder to a slip ring unit from which leads to control and recording equipment extend, the instrumentation serving to monitor crack propagation under the conditions of high speed revolution which induce a hoop stress in the material approaching its yield stren

Abstract: A method for measuring thermal waves in a sample is disclosed. More particularly, thermal waves, which may be used for imaging, are generated in a sample through local periodic heating as, for example, by impinging an intensity modulated beam of energy on the surface of the sample. A laser probe is focused on a portion of the heated area on the surface of the sample in a manner such that the beam is reflected from the surface. The angular displacement of the reflected beam, resulting from the local angular change in surface conditions of the sample due to the thermal waves are monitored. By this arrangement, the displacement of the reflected beam can be used to detect the thermal waves.

Abstract: A method and apparatus for optically making physical measurements of materials which deform upon application of heat thereto. The device comprises a source of light, an at least partly transparent chamber having a heating source which can be programmed to operate as a function of time, and with a porous support designed to support a deformable material within the chamber. A photo-electric receiver 5 and an optical lens 7 are also provided for imaging of the material during deformation on the photo-electric receiver. In order to perform the imaging, the source of light, the porous support, the photo-electric receiver and the optical lens 7 are optically aligned. In a specific application, the apparatus can be used to determine the wetting power of pitches.