Abstract: A device for determining the shear strength of rock and soil is disclosed. The device includes means for supporting the device within a borehole, a primary shaft, a plurality of shearing units slidably attached to the shaft having shear heads which are movable from a retracted position to a material-engaging expanded position, and a slip joint between adjacent shearing units such that the units operate independently from one another. The shearing units apply progressively greater normal forces on the material to be tested and sequentially shear the material being tested.In operation, the device is lowered into a borehole. Then the shearing units are moved from their retracted position to their expanded material-engaging position so as to apply progressively greater normal forces on the material to be tested. An axial force is then applied to the shaft so that the material engaged by the shearing unit closest to the anchor shears.

Abstract: A gauge for use with a test specimen that is made of a preselected ablative material to be tested, and that is in a high temperature gaseous flow (i.e., a hot environment) which is capable of ablating the test specimen, and which also is capable of inducing, and of exerting on the test specimen, a resultant shear force (i.e., a shear force vector) that comprises constituent axial and lateral forces. The test specimen is bonded on the mounting surface of a block member (of the gauge) that is positioned on bearings, within a housing, for movement in axial and lateral directions. A plurality of force sensors are positioned around the perimeter of the block member, and the constituent axial and lateral forces of the resultant shear force that is acting on the test specimen are transmitted to these sensors. The components of the gauge are protected from shock by their structure and positional relationship, and are protected from overheating by the water-cooling of the housing.

Abstract: A viscometer wherein a sample of the material to be tested is introduced into the annular clearance between a stationary cylinder and a vertical shaft which carries several weights. As the shaft descends at a speed which is a function of the combined mass of weights and the viscosity of the sample in the clearance, successive weights are automatically detached from the shaft, either by piling up on top of each other after the lowermost weight comes to rest on a platform, or by being intercepted by plates which are mounted at different levels. Means is provided for centering the weights prior to start of a multi-stage test and for returning the shaft and the weights to starting positions upon completion of a multi-stage test.

Abstract: A shear transducer having two cylindrical bending beams with two full strain gage bridges so arranged to cancel acceleration induced by forces in the axis of interest.