A system for simultaneously measuring the indentation hardness properties, span properties, and resilience properties of a mattress includes a first indentation means and a second indentation means, and means for urging the first indentation means and the second indentation means into the mattress with a predetermined force, and also includes laser means for projecting a laser line configured to map, preferably by photographic triangulation, the amplitude, shape, and time-dependency of the resultant deflection of the mattress surface between the first indentation means and the second indentation means. A method for simultaneously measuring the indentation hardness properties, span properties, and resilience properties of a mattress is also provided.

An intelligent test system for traffic load engineering detection of road construction comprises a support part; a sample box part used for containing samples and carrying out a load test in a vertical direction and a direct-shear test in a horizontal direction; a simulated road load applying part used for applying multiple simulated road loads to the samples; a vertical load applying part used for providing multiple loads in the vertical direction for the samples; a horizontal load applying part used for providing loads in the horizontal direction for the sample box part; an automatic sand-compaction part used for quantitatively compacting the samples layer by layer; a water-level fluctuation part used for simulating rising and falling of a tide level; a dry-wet cycle part used for simulating a rain and a sunlight; and an acquisition part used for acquiring data generated during the test.

A method is provided for increasing accuracy in measuring complex Young's modulus and complex shear modulus of a material using a processing system. The material is tested to obtain an experimental frequency response transfer function of normal displacement to input force. A model panel is developed in the processing system as a modeled frequency response transfer function. The modeled transfer function is used at a range of fixed frequencies to calculate displacements of the model panel divided by the input force while varying material parameters. The modeled frequency response transfer function is compared with the experimental frequency response transfer function to compute error function values. These values indicate the most accurate material property values as those minimizing the computed error function values.

A strain state of a bending outside surface of a test specimen is photographed by use of a camera without falling out of focus during a bending test. A bending test facility for a metal sheet material for an automobile body includes a supporting member that supports two supported portions of a flat test specimen formed of the metal sheet material for an automobile body, a punch for performing a bending test in which an area between the two supported portions of the test specimen is pressed from an opposite side to the supporting member so that the test specimen is bent to be deformed, and a camera for photographing, from the side of the supporting member, a bending outside surface of the test specimen during the bending test using the punch, with relative positions of the punch and the camera during the bending test being fixed.

Utilizing multiple rock cores samples obtained while drilling a well to determine the mechanical properties of the rock constituting the wellbore and formation zones within the wellbore. A geomechanical model is created from the samples by nanoindentation testing to provide the raw data from which the geomechanical model is then created.

An apparatus for testing a razor blade comprises a base, a material support table, a material sample, a transport carriage, a blade retention assembly, and a razor blade. The material support table is supported by the base. The transport carriage is movably coupled with the base and is movable with respect to the material support table between a start position and an end position. The blade retention assembly is movably coupled with the transport carriage and is movable with respect to the material support table between a blade-engaged position and a blade disengaged position. The blade retention assembly is movable together with the transport carriage between the start position and the end position. The blade is releasably attached to the blade retention assembly. The razor blade contacts the material sample when the blade retention assembly is in the blade-engaged position. Methods are also provided.

A steel pipe collapse strength prediction model generation method, a steel pipe collapse strength prediction method, a steel pipe manufacturing characteristics determination method, and a steel pipe manufacturing method capable of highly accurately predicting the collapse strength of a steel pipe after forming or a coated steel pipe in consideration of the pipe-making strain during forming. Into a steel pipe collapse strength prediction model generated by the prediction model generation method, steel pipe manufacturing characteristics including the shape of a steel pipe to be predicted after forming, strength characteristics, and the pipe-making strain are input to predict the collapse strength after forming. Into a steel pipe collapse strength prediction model, steel pipe manufacturing characteristics including the shape of a coated steel pipe to be predicted after forming, strength characteristics, the pipe-making strain, and coating conditions are input to predict the collapse strength of the coated steel pipe.

Techniques for determining rock properties include exerting a compressive load with a test apparatus across a rock sample that includes a specified length-to-diameter ratio; measuring, with a strain gauge, a strain on the rock sample during the compressive loading; determining, based at least in part on the compressive load, a mechanical property of the rock sample; and determining, based at least in part on the measured strain and the compressive load, an elastic property of the rock sample.

The present invention discloses a method for evaluating and preventing creep damage to conductivity of hydraulic fracture in gas reservoirs, comprising: (1) selecting a rock sample of target reservoir for creep experiment, and plotting ε-t curve of the rock sample during creep; (2) fitting the fractional Kelvin model with the ε-t curve of the rock sample during creep; (3) calculating the conductivity and permeability of hydraulic fracture considering creep damage; (4) numerically solving the productivity model, calculating the cumulative gas production of the gas well produced up to time t, and calculating the creep damage rate for cumulative production of the gas well; (5) repeating Steps (3) to (4), calculating the creep damage rate for cumulative production for the cases of hydraulic fracture sanding concentration N of 5 kg/m.sup.2, 7.5 kg/m.sup.2, 10 kg/m.sup.2, 12.5 kg/m.sup.2 and 15 kg/m.sup.2 respectively, plotting the creep damage chart of cumulative production.

A method and apparatus for testing rings cut from pipes for use in making subsea pipelines are described. The method for determining the whether a test ring is correctly assembled in a test chamber for testing pipes for use in making subsea pipelines comprises: mounting a test ring in a pressure chamber such that the ends of the test ring forms seals with opposing surfaces of the chamber to isolate the inside of the test ring from the outside; providing means for measuring the displacement of the test ring; providing means for measuring a force applied to the inner surface of the test ring; applying a force to the inner surface of the test ring; and using the displacement measurement and force measurements to determine whether the test ring is correctly mounted in the pressure chamber.