Abstract: A fully automatic test system is provided to nondestructively determine the elastic constant information of paper samples. Two ultrasonic wave sensors are mounted in alignment with the instrument frame at respective distances from an ultrasonic generator. A motor driven turntable beneath the sensors and generator supports a paper test specimen for automatic progression of the specimen fiber orientation relative to the sonic wave propogational direction. Electronic data processing equipment resolve ultrasonic emission and reception signals for quantitative determination of the sonic velocity through four directional transmission modes of a specimen. Such sonic velocity data enables determination of four in-plane elastic parameters.

Abstract: In the joinder of successive sections of pipe or casing, as in oil well applications, the quality of the joinder during makeup is measured by sensing actual bearing pressure. A deformation resistant member such as a chain having solely point contact engagement with the pipe collar includes a short sensor section deformable within its yield limits and is wrapped about the collar in the mid-region of its threaded portion. As the pipe is threaded into the collar, bearing forces exerted on the collar are measured by strain gauges in terms of the extension of the sensor section. The non-yielding character of the chain and its transverse span provide both an integration of the circumferential deformation within the band of interest and a substantial mechanical gain at the sensor section.

Abstract: The invention provides a sensor comprising a plate resting on two supports by simply bearing thereon, for creating in said plate uniform bending stresses in a defined zone of said plate. Detector means for detecting the stresses undergone by said plate may be placed in said zone without their location being defined with precision.

Abstract: In an ultrasonic inspecting apparatus, propagation time is measured between a transmitting point of an ultrasonic wave from outer circumference of a subject material and a receiving point of the ultrasonic wave at another point on the outer circumference spaced apart from the transmitting point by a predetermined angle, and a predetermined sequence of operations is performed with the measured propagation times and the known constants, thereby internal information concerning the material, including location and shape of a defect existing therein, is provided.

Abstract: In order to determine the fatigue limit of elastic materials, especially rubber, under completely reversed stress by applying a load which alternates between zero and a maximum value and in order to determine the number of load alternations which leads to the breaking of the material, a plurality of strip-shaped rubber samples are clamped between two stationary clamping beams and a rocker. The rocker is approximately parallel to the beams and is moved at one end thereof by means of a crank mechanism. The rubber samples are each positioned parallel to one another in at least one row and are alternately stretched and relaxed to a different extent, depending on their spacing from the fulcrum of the rocker.

Abstract: A method and apparatus for precisely controlling plastic strain rate during plastic deformation testing of a solid material such as a metal or plastic are described in which the effects of elastic strain rates associated with the specimens and machines used for such testing are eliminated by applying corrections proportional to the load on the specimen. Thus strain rate sensitivity, unaffected by the machine or specimen modulus can be measured. Strain rate sensitivity can be used to measure the activation volume of the specimen which may be used for quality control of material processing and/or manufactured articles.

Abstract: A vehicle able to move between two walls and particularly in the space between two vessels of a fast neutron reactor, for inspection and testing; the vehicle having two wheels bearing on one of the two walls and connected to the vehicle body by two longitudinal arms and two wheels bearing on the other wall and arranged symmetrically with respect to the previously mentioned wheels and connected to the vehicle body by two transverse arms. The longitudinal and transverse arms may be folded back to permit the passage of the assembly through an opening.

Abstract: The method for measuring strains in a part uses the reflection of an acoustic wave, while measuring a transit time of said wave by means of an apparatus which measures the fade-in time of an echo coming from an interface. The method comprises the steps of selecting within the medium one or a plurality of ends of rectilinear measuring runs, which ends are embodied by an inner artificial reflector (8, 9) emitting of a beam of acoustic waves so that acoustic rays carrying sufficient energy strike the useful reflectors, selecting the echoes corresponding to the reflectors, determining by measurement the transit times which are characteristic of the useful acoustic rays up to the inner artificial reflectors and transposing the transit times for each inner reflector considered individually or the respective differences of transit times for each couple of reflectors into an outer strain value or into a strain value within the region delimited by each couple of reflectors.

Abstract: An improved interface in a vibration testing apparatus for attaching a slip plate, adapted for carrying the specimen to be tested, to a vibration generator, commonly referred to as a shaker machine. The interface comprises a plurality of jam nut assemblies designed to attach to the slip plate by threading into tapped holes in the edge of the plate and to the shaker machine via a specially designed bullnose.

Abstract: A fluid chamber assembly having an improved shape to enhance the reception of the first arrival of the signal from the transmitter transducer which has passed through the cement or fluid sample within the fluid chamber assembly and an improved sealing arrangement for the fluid chamber assembly.

Abstract: An apparatus for applying and measuring a variable bending load to a fiber reinforced plastic test specimen under desired temperature and humidity conditions. The apparatus comprises a frame member including means for holding the ends of the test specimen while applying a bending load to the center of the test specimen.

Abstract: A transducer unit comprised of a pair of transducers coupled together in a manner such that the offsets, drifts and the like of the circuit elements of one transducer are opposed by and cancelled out by the circuit elements of the other transducer. The transducers can be in the form of Wheatstone bridges and each of the branches of the bridge contains a circuit element of each transducer, respectively, the circuit elements of the branches of the transducer unit being in opposition to each other so as to cancel out the effects due to temperature, acceleration, aging and the like.

Abstract: A system for monitoring the vibration of a power driven cutting tool during machining first produces a signal proportional to the vibration spectrum of the tool over a preselected band width. This is passed through a digitally controlled attenuator which is adjusted to provide an output signal at a preselected level. The degree of attenuation is stored, as is a reference value which is generated as a function of the attenuated signal. Then, during subsequent machining operations under the same machining conditions the attenuator is controlled to provide the same degree of attenuation and the reference value, which is in the form of a digital signal, is compared with the rectified and digitized output of the attenuator. When the latter exceeds the reference value a control signal is generated which either provides an audible or visual warning that the cutting tool is worn and therefore due for replacement or initiates an automatic tool changing operation.

Abstract: The invention provides apparatus for ultrasonically testing the edges and/or the body of a metallic workpiece, utilizing water as a coupling medium between ultrasonic transducers and a metallic product moving relative to the testing apparatus along a predetermined pathway; which apparatus comprises guide means defining the pathway to be followed by the metal product, one or more reservoirs being the pathway each incorporating a top opening through which water can overflow to contact successive parts of the piece to be tested, located thereabove and a plurality of ultrasonic transducers located in one or more groups within the reservoir or reservoirs and directed towards the edge or body of the piece to be tested so that they may be static, adjustable transverse to the direction of movement of the product along the pathway, or reciprocate in a sinusoidal manner to traverse all or part of the pathway.

Abstract: A ceramic product is exposed to a light from a tungsten lamp, so that a specified region of the product is heated. In this heating process, acoustic emissions from the ceramic product are detected by an AE sensor which is acoustically coupled to the ceramic product by means of a waveguide passage. A temperature gradient directed from the surface toward the inner part of the ceramic product is formed by heating, and thermal stress is applied to the product so that tensile stress is produced in the inner part of the product. In practical use, a crack constituting the core of fracture is caused to grow by the thermal stress, and an acoustic emission is released. The existence of a defect can be evaluated by detecting the acoustic emission. Also, the location of the defect in the product can be detected by heating part of the product. The equivalent crack dimension a.sub.

Abstract: A process of utilizing ultrasound for acquiring data representative of the internal portions of a structure and the display of the data thus obtained. This process includes the emitting of sequences of ultrasound to the structure under consideration and receiving therefrom corresponding echoes. For each sequence two groups of transducer elements are selected for generating ultrasound beams of possible N different focal characteristics sequentially. The ultrasound beams alternate from one group to the other except when a given beam corresponds to the most distant focal zone. In that case, the succeeding emission is carried out without alternating, i.e., the emission is generated from the same group.

Abstract: A system of transducers and electrical circuitry connecting with the transducers detects and locates flaws in the metallic walls of vessels used for containing and transporting liquids. An array of transducers is carried by a sled having rollers for facile movement about the surface of the vessel which surface is submerged within the liquid to permit the liquid to provide a sound propagating medium between the transducers and the vessel wall. The transducers are arranged in sets of two transducers, one of which is a transmitting transducer and the other a receiving transducer, the two transducers being positioned in tandem for increased azimuthal coverage of the sonic radiation.

Abstract: This invention is a device to test fastener heads and thread run-out areas for mechanical strength and detect defects. A fastener head is placed through a hole in a wedge-shaped washer and the shaft put under tension so that the fastener head completely contacts the wedge shaped washer. The stress produced is calculated to be within the elastic limit of the material and produces a stress in the shaft near the fastener head similar to that shown in FIG. 3. If the fastener is defective or is non-conformant to state-of-the-art standards, the fastener will fail when this test device is used. This method allows improved detection of hydrogen embrittened and improper heat treating processes which results in fasteners that will have unsatisfactory mechanical properties.

Abstract: Ultrasonically testing of an article at high temperatures is accomplished by the use of a compact layer of a dry ceramic powder as a couplant in a method which involves providing an ultrasonic transducer as a probe capable of transmitting shear waves, coupling the probe to the article through a thin compact layer of a dry ceramic powder, propagating a shear wave from the probe through the ceramic powder and into the article to develop echo signals, and analyzing the echo signals to determine at least one physical characteristic of the article.

Abstract: An ultrasonic linear array water nozzle (10, 10A) wherein water is coupled with ultrasonic energy between linear array transducers (126) and a workpiece (132) under inspection. The nozzle includes a water receiving plenum chamber (22) extending for the length of the nozzle and for the length of linear array transducers. Plenum chamber (22) supplies water immediately downstream of the transducers where water is coupled with ultrasonic energy from the transducers. The nozzle has a main body (88) downstream of the transducers and has downstream water paths in the form of waveguides (190) which are spaced by air gaps (186), the waveguides each extending downstream in the shape of an exponential horn. The waveguides (190), formed by consecutive plates (168) having air gaps (186), are each in respective alignment with an individual transducer (126).