Abstract: Grip apparatus for tensile strength testing of geosynthetic materials includes a pair of opposing first and second grip bars slidably mounted in a frame. Selectively operable locking elements carried on the frame and the first grip bar enable selective fixation of the first grip bar at a desired position with respect to the second grip bar when inserting or removing or loading test specimens. Various constructions of grip bars, and grip jaws mounted on the bars, are provided, including replaceable high friction surface rods, grip surfaces with alternating grooves and shoulder surfaces, and easily replaceable L-shaped grip jaws that do not require disassembly of the apparatus. A plurality of actuating shafts impart movement and grip forces to each grip bar, with the actuating pumps for the shafts being operable simultaneously, separately, synchronously or asynchronously.

Abstract: A fixture for securing a plurality of circuit boards during vibratory testing is shown, wherein the fixture comprises a first end fixture member having a first wall surface, and a second end fixture member space from the first end fixture member. The second end fixture member has a second wall surface facing the first wall surface, and the first and second end fixture members are relatively movable so as to very the spacing therebetween. Each of the first and second wall surfaces includes a plurality of spaced parallel notches for securing the opposite edges of a circuit board, and each of the notches is to have resilient characteristics to accommodate dimensional variations between similar circuit boards and an included angle in a range of 110.degree. to 130.degree. in order to secure a circuit board so that it is free to vibrate in a free-free manner during the vibratory testing.

Abstract: A set of film clamps and a mounting block for use in the determination of tensile modulus and damping properties of films in a manually operated or automated Rheovibron. These clamps and mounting block provide uniformity of sample gripping and alignment in the instrument. Operator dependence and data variability are greatly reduced.

Abstract: An apparatus and method for measuring the alignment of a clevis and pin type loading fixture for compact tension specimens include a pair of substantially identical flat loading ligaments. Each loading ligament has two apertures for the reception of a respective pin of the loading fixture and a thickness less than one-half of a width of the clevis opening. The pair of loading ligaments are mounted in the clevis openings at respective sides thereof. The loading ligaments are then loaded by the pins of the loading fixture and the strain in each loading ligament is measured. By comparing the relative strain of each loading ligament, the alignment of the loading fixture is determined. Preferably, a suitable strain gage device is located at each longitudinal edge of a respective loading ligament equidistant from the two apertures in order to determine the strain thereat and hence the strain of each ligament.

Abstract: Apparatus for measuring the hardness of capsule plugs, granules and pellets, in which a power stand (11) has a base (12) and gear motor (15) for driving a replaceable probe (25) toward a test subject supported on the base. A test subject holder (27) is placed on the base for holding the test subject, and comprises spaced apart first and second support plates (28, 30) fixed relative to one another with a third support plate (29) movable therebetween to define a space variable between zero and a predetermined maximum. Accordingly, a test subject may be held on the support for testing in a selected one of a variety of modes, including crushing, bending and cutting, depending on the spacing of the plates and the probe selected.

Abstract: A double or multiple bevel culet geometry is used on a diamond anvil in a high pressure cell apparatus to provide increased sample pressure and stability for a given force applied to the diamond tables. Double or multiple bevel culet geometries can also be used for sapphire or other hard crystal anvils. Pressures up to and above 5 Megabars can be reached.

Abstract: A grip for a material testing load frame including a grip plate for engaging the end of an elongated sample having a longitudinal axis and a grip body having one end for connecting to the grip plate and another end for connecting to a loading component of the frame, a mechanism for adjusting the concentricity of the plate with respect to the body, and a mechanism for adjusting the angle of the plate with respect to the body, so that when the sample end is engaged by the plate, and the grip body is connected to the loading component, the longitudinal axis and the axis of the loading component can be aligned with respect to the concentricity and angle.

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 and apparatus for testing samples of viscoelastic materials are shown, in which the sample is contained under pressure between two dies and the forces involved in rotating one die with respect to the other. The method uses different frequencies of oscillatory rotation at different temperatures. The apparatus uses dies with discontinuous protrusions which overlap each other.

Abstract: A method and apparatus for supporting concrete testing samples comprising providing closely machined aluminum, steel, or suitable molded plastic caps for the respective circular ends of a cylindrical concrete testing sample and removable, reusable flanged molded elastomeric pads which are inserted in a recessed cavity in each cap prior to positioning of the cap on the respective end of the concrete cylinder. Each pad has a space between the bottom and the side to provide at least an equivalency between sulfur capped cylinder compression load strengths and those generated by the above system over the wide range of compression load values normally occurring in this particular test.

Abstract: A piezoelectric vibration exciter for generating mechanical vibrations for the purpose of destructive material or specimen testing has two equally sized disk stacks, each with an even number of piezoceramic disks. A vibration armature serving as a clamping device for the test specimen is arranged between the two disk stacks in a stiff clamping frame having a bail and a base plate. The assembly containing the disk stacks and the vibration armature is clamped in position in the stiff clamping frame. The piezoceramic disks are energized with an AC voltage so that one disk stack will axially contract in phase with the voltage, while the other disk stack will axially expand. As a result, the vibration armature and the test specimen arranged between the disks reciprocate at the frequency of the AC voltage input.

Abstract: The present invention relates to a device for stressing a deformable material specimen. The apparatus consists of top plate 11 and bottom plate 12 sandwiching a guide cylinder 13. The specimen 14 is positioned on the bottom plate 12 and attached to a load piston 20 (FIG. 2). Force is applied through top plate 11 into guide cylinder 13. Once specimen 14 has been loaded, the stress is maintained by tightening tie bolt nuts 17.

Abstract: The rheological properties of a viscoelastic material are measured by enclosing a sample of the material between two die members which have protrusions extending therefrom and intermeshing to form shear zones therebetween. The sample is sheared by displacing one member with respect to the other and the displacement force is measured.A die is provided for the test, and means to bias the die members toward each other, to seal them together, to move one member with respect to the other and to measure the force required for such movement are provided.

Abstract: A test gage for measuring the decrease in one dimension of a test specimen having a frame member with a sliding member positioned within the frame member. The test apparatus is adapted to receive a test specimen between the sliding member and one side of the frame member. The sliding member is held in contact with the test specimen by a spring. A proximity measuring device senses the position of the sliding member with respect to the frame member and provides an output signal proportional to displacement. Elastic bands are used to support the test gage on a tensile test machine which is used to apply a stress to the test specimen.

Abstract: A testing apparatus comprising two platens one of which is a self-aligning pecimen contacting platen which includes an upper portion comprising a first member which contacts the specimen and a second member which is spaced from a base by a plurality of balls. The first and second members are movable relative to each other to pivot the specimen into proper alignment between the platens when the specimen is subjected to compression. The plurality of balls are juxtaposed between and engage the second member of the upper portion and the base and serve to support the upper portion for lateral and rotational movement relative to the base to facilitate alignment.