Drop-weight tower (110) for reproducibly initiating a crack in a material sample for fracture mechanics testing comprising a base (120) with a top surface upon which a sample holder (124) is mounted to grip a material sample, an attachment column (140) having a linear rail (142), a carriage (162) attached to the linear rail (142) and a stage (164) is attached to the carriage. The stage (164) includes a vertical rod (184) and a razor-blade holder (178). A weight is slidably mounted to the vertical rod (184). The carriage is used to adjust the height of the stage (164) relative to the material sample. A hammer (180) slides up and down the vertical rod (184) to apply consistent and reproducible force on the razor (178) that then initiates the crack in the material sample.

The present disclosure relates to an information processing device, an information processing method, and a program for enabling more accurate prediction of a crack to be made. A model acquisition unit acquires a structure model M.sub.D from a model generation unit, an external device (not illustrated), or the like. Amplitude load energy A in an element E0 having no cracks is set on the basis of a relationship between an equivalent stress σ and an equivalent elastic strain ε experimentally obtained according to a material constituting the element E0. Since the equivalent elastic strain ε depends on a crack variable φ, the amplitude load energy A is expressed as a function of the crack variable φ. A crack prediction unit predicts a crack to be generated in a structure D by calculating a differential equation having a term proportional to the amplitude energy. The present disclosure can be applied to, for example, a crack prediction device that predicts a crack.

An apparatus and a method for measuring a creep crack growth property using a small specimen with a micro groove are provided. The apparatus for measuring a creep crack growth property includes a lower die on which an edge of the specimen is mounted and which includes a lower die hole formed in the center thereof, an upper die coupled to an upper portion of the lower die so as to fix the specimen, and a punching unit inserted into an upper die hole formed in the center of the upper die so as to press an upper surface of the specimen, wherein a semielliptical micro groove is formed in a lower surface of the specimen to measure a creep crack growth property.

A method for preparing a SiC ingot includes: disposing a raw material and a SiC seed crystal facing each other in a reactor having an internal space; subliming the raw material by controlling a temperature, a pressure, and an atmosphere of the internal space; growing the SiC ingot on the seed crystal; and collecting the SiC ingot after cooling the reactor. The wafer prepared from the ingot, which is prepared from the method, generates cracks when an impact is applied to a surface of the wafer, the impact is applied by an external impact source having mechanical energy, and a minimum value of the mechanical energy is 0.194 J to 0.475 J per unit area (cm.sup.2).

A device for testing mixed-mode fatigue crack growth rate includes a plate-like specimen, and a first fixture mechanism for exerting stretch, shear and torsion actions on the specimen via a second fixture mechanism. The second fixture mechanism is used for clamping the specimen and enabling the specimen to generate a mixed-mode fatigue crack in cooperation with the first fixture mechanism. The device further comprises a fatigue crack measurement instrument for measuring and recording the length of mixed-mode fatigue crack generated on the specimen.

A window drop test apparatus includes a support protruding in a first direction from the prop, and a guide portion that defines a drop space together with the support, where a drop test is performed through the drop space.

A destructive inspection method of a vitreous silica crucible for pulling a silicon single crystal evaluates a crack state of an inner surface of the vitreous silica crucible supported by a graphite susceptor when a load is instantaneously applied to at least one point on the inner surface via an automatic center punch while pushing the tip portion of the automatic center punch against the inner surface. The destructive inspection method can inspect the vitreous silica crucible under conditions as close to the actual conditions of use as possible.

The invention relates to a device for carrying out bending tests on panel-shaped or beam-shaped samples (1), in which two rotary drives are arranged at a distance from one another and a flange (3) is fastened to each of the drive shafts of the rotary drives, said drive shafts being oriented parallel to one another. At least two bar-shaped bending elements (2) oriented parallel to the axis of rotation of the drive shafts and arranged at a distance from the axis of rotation and at a distance from one another are provided on each of the flanges (3). A panel-shaped or beam-shaped sample (1) can be introduced between the two bar-shaped bending elements (2) on the two flanges (3). In the event of rotation of the rotary drives in opposite directions of rotation, bending forces are exerted on the sample (1) and each of the two rotary drives can be controlled individually and connected to an electronic open-loop or closed-loop control unit.

The present invention provides a method of surely detecting a crack in piezoelectric elements regardless of size of the crack. The method includes applying voltage to a first piezoelectric element of a pair of piezoelectric elements to cause deformation in the first piezoelectric element, forcibly deforming a second piezoelectric element of the pair of the piezoelectric elements to generate voltage from the second piezoelectric element according to the deformation of the first piezoelectric element, finding a transfer function of the pair of the piezoelectric elements based on values of the applied voltage and the generated voltage, and detecting presence or absence of a crack in the pair of the piezoelectric elements based on an objective value obtained from the found transfer function.

The present disclosure involves a method for determining the critical local expansion of a component with an eye toward the appearance of edge cracks based on an expansion of the component in the shaping process. Given a local expansion of the component at the edges that is smaller than the critical local expansion, no edge cracks arise that are larger than 1 μm. In particular, at least one expansion test is performed with at least one test component, and a critical overall expansion is determined with the at least one expansion test. The local maximum expansion of the test component is determined that the test component exhibits at the time of the critical overall expansion of the test component, and the local maximum expansion is the critical local expansion.