An elastic matrix determination method for a laminated iron core, which can optimally determine a shear modulus in two planes including a laminating direction of the laminated iron core included in an elastic matrix in a constitutive equation representing a stress-strain relationship used for vibration analysis, and also provided is a vibration analysis method. When performing a vibration analysis of a laminated iron core formed by laminating steel sheets using a constitutive equation representing a stress-strain relationship in a matrix representation, a shear modulus in two planes including a laminating direction of the laminated iron core included in an elastic matrix in the constitutive equation is determined depending on an average tightening pressure in the laminating direction of the laminated iron core.

A portable soil body in-situ shear test device includes four parts: an active force system forming arranged externally, a passive shear system and an electromagnetic loading system forming arranged internally, and a ring knife system arranged at a bottom. Compared with the conventional in-situ soil shear strength test device and test method, the present invention is convenient to install and carry as well as simple to operate, and has strong applicability. The present invention is suitable not only for layered soils with large cross-plate shear test errors, but also for soils with different consolidation degrees at various sites and various terrains. A test method adopting the device can simulate the shear strength of the soil mass under different overburden loads without disturbing the mechanical properties of the in-situ soil mass, which has high promotion value in the test of in-situ soil shear strength.

A clamp and a shear test device are provided, and relate to the technical field of rock mass mechanics tests. The clamp comprises a box body, wherein an opening is formed in one side of the box body, two clamping structures are oppositely arranged in the box body, a sample is arranged between the two clamping structures, each clamping structure comprises an adjusting mechanism, and a distance between the two clamping structures is adjusted through adjusting mechanisms of the two clamping structures. According to the clamp, real-time dynamic adjustment is conveniently and rapidly achieved, the stability of sample clamping is ensured, and therefore the requirement that the shear load can be truly and effectively transmitted to the sample through the box body is met.

A system and a method for measuring drilling damage in fiber reinforced plastic (FRP) composites is described. Multiple holes are drilled in the FRP composite using a drill having nominal diameter, and the FRP composite is separated into multiple drilled blocks. Each block, covered with the black substrate, is scanned on a scanner to generate a scanned image depicting a hole region, a background, and delamination damage peaks. For each scanned image, a maximum delamination damage peak and a maximum diameter of a first circle concentric with the drilled hole and passing through tip of the maximum delamination peak, are measured. Further, a delamination size and a delamination factor are calculated based on the maximum diameter of the first circle and the nominal diameter of the drill.

An apparatus for testing tangential and normal resistance of an anchor chain and soil under an equivalent elastic boundary and a method therefor, and the apparatus includes a support frame, a transmission device (4), an air pressure loading system, a test box (5), a vertical displacement applying part (6), a tangential anchor chain unit (7), a normal anchor chain unit (8), etc. The present disclosure can, by using a spring of equal stiffness to simulate the elastic boundary and being capable of overcoming an influence of boundary conditions, greatly reduce a size of the test box, thereby effectively saving materials and reducing difficulty of a test operation; moreover, it integrates the normal and tangential resistance tests into one, which can measure tangential and normal interactions of the anchor chain and the soil at the same time.

A device for measuring equivalent shear stress between a shield screw conveyor and modified muck includes a spiral shell, a spiral device, a data calculation module and measurement components, the measurement components include a torque measurement component configured to measure spiral driving torque between the spiral device and the modified muck, an angle measurement component configured to measure a conveying angle of the modified muck, a parameter measurement component configured to measure structural parameters of the spiral device, and a density measurement component configured to measure an average density of the modified muck. The torque measurement component, the angle measurement component, the parameter measurement component and the density measurement component are respectively connected to the data calculation module, and the spiral device is installed in the spiral shell.

A method for assessing an effect of hypoxia on a tissue includes providing a sample of the tissue in a hermetically sealed container, determining a first amount of a reaction substrate (e.g., protocatechuic acid) to be introduced into the sealed container and determining a second amount of a reaction enzyme (e.g., protocatechuate dioxygenase) to be introduced into the sealed container. The method further includes introducing the reaction substrate and the reaction enzyme into the sealed container. At least one of the first amount of the reaction substrate and the second amount of the reaction enzyme is selected to induce at least one of a predetermined amount of hypoxia less than anoxia and a predetermined rate of hypoxia in the tissue during a reaction between the reaction substrate and the reaction enzyme. Values of properties of the tissue can be measured before and after the reaction to assess effects of hypoxia.

A uniaxial bidirectional synchronous control electromagnetic loaded dynamic shear test system and method, a test apparatus thereof including a support platform, a loading bar system, an electromagnetic pulse generation system, a servo-controlled normal pressure loading system, and a data monitoring and acquisition system. The test apparatus can be used to conduct a dynamic shear test research on a rock-like material under a constant normal pressure close to an actual operating condition, and can also be applied to carry out dynamic shear tests on intact rock-like test specimens in various sizes or jointed rock-like test specimens containing a single structural surface to study dynamic shear mechanical property and shear failure behavior under strain rate of 10.sup.1−10.sup.3 s.sup.−1, thereby providing an important theoretical and technical support for the design, construction, protection, and safety and stability evaluation of geotechnical engineering, structural engineering.

A test apparatus used for simulating debonding between a carbon fiber reinforced polymer (CFRP) and concrete in a CFRP-strengthened structure consists of a primary structural block, a secondary structural block, an adjustable hanger, a receiving slot, an attachment mechanism, a pull-off disk, a connecting plate having a plurality of rods. The adjustable hanger and the secondary structural block are slidably positioned into the receiving slot that traverses into a structural body of the primary structural block. The adjustable hanger is mainly used during double-shearing tests and mixed-mode tests, wherein both shearing and peeling is analyzed in mixed-mode tests. The secondary structural block is used in double-shear tests, mixed-mode tests, single-shear tests, tension pull-off tests, and beam-bend tests. The attachment mechanism, which holds the primary structural block, the secondary structural block, and the adjustable hanger together, is also used during single-shear tests and beam-bend tests.

A first shaft segment and a second shaft segment are joined by a first fastener and a second fastener to form a shaft test assembly. The first shaft segment and the second shaft segment are each curved between first and second circumferential ends. A method of testing a shaft includes displacing a first applicator part relative a second applicator part to exert a load on the shaft test assembly. The resulting shear stress on the shaft test assembly can be measured to determine material properties of the shaft. A first applicator part extends at least partially into the shaft test assembly and interfaces with the first shaft segment to apply a load. A second applicator part extends at least partially into the shaft test assembly and interfaces with the second shaft segment to apply a load.