An indentation head system for an indentation instrument includes: an indenter tip contacting a sample surface along at least an indentation axis; a reference element supporting the tip; a zero-level sensor generating a signal indicating whether the tip is displaced with respect to the reference element from a neutral relative position; an elastic element between the tip and an actuator with known elongation, the actuator connected to the reference element; and a controller receiving signals from the zero-level sensor to perform servo control of the actuator based on output of the zero-level sensor and the known elongation of the actuator so the zero-level sensor outputs a signal corresponding to a substantially zero displacement of the tip from the neutral relative position, the controller calculating a force applied by the tip to the sample based on an output of the displacement sensor and an elastic coefficient of the elastic element.

A rotary shock testing machine including: a base; a shaft rotatable relative to the base; a test disc for holding one or more specimens to be tested, the test disc being rotatable with the shaft; an actuator for applying a rotation to the shaft and test disc; and a brake for applying a braking force to the test disc to subject the one or more specimens to a rotary shock.

An apparatus and a method for in-situ testing impact strength of a micro-structure are provided. In one embodiment, the apparatus includes: a flexible beam, one end of which being fixed; an impact mass block disposed at the other end of the flexible beam and being for exerting an impact on the micro-structure; and a locking member including a beam arm and a plurality of locking teeth. The beam arm is perpendicular to the flexible beam and one end of the beam arm is fixed, and the plurality of locking teeth are distributed at intervals along the beam arm, such that the other end of the flexible beam is engaged to one of the plurality of locking teeth when the flexible beam is loaded.

Utilizing a load generated by a non-linear spring, a spring constant of which increases as an amount of deformation increases, a measuring apparatus presses an indenter against a material surface and evaluates material characteristics. The measuring apparatus includes: an actuator that causes the non-linear spring to deform; a scale that measures the amount of deformation of the non-linear spring when the non-linear spring is deformed; and a controller that stores non-linear spring characteristic data for reciprocally calculating the amount of deformation and the load, and that drives the actuator based on the amount of deformation and the non-linear spring characteristic data such that the load reaches a target load.

A method for testing a helmet for effectiveness of user protection includes moving a load along a predetermined path, supporting a target body at an impact location in the predetermined path, the target body including a head model and a helmet disposed on the head model, and impacting the target body with a force generated by the moving of the load. The impacting of the target body entails contacting the target body with an impactor free to move perpendicularly and tangentially relative to a surface of the target body. The supporting of the target body is at least reduced, if not eliminated, before or during the impact of the impactor with the target body at the location. Forces generated are automatically measured or sensed during the impact of the impactor with the target body at the location.

A method and apparatus for measuring a dynamic tensile stress and/or tensile strain response of a material such as an elastic material and/or a ductile material. The apparatus may include a striker bar, a stretcher bar, and a drive assembly configured to propel the striker bar toward the stretcher bar. The apparatus may further include a stationary specimen mount and a movable specimen mount that receive a test sample. The striker bar and the stretcher bar of the apparatus may provide a continuous stress on the test sample and an accurate tensile stress/strain measurement.

An apparatus for measuring for measuring coefficient of restitution which is capable of reducing a mass effect and performing tests in free directions, is disclosed. The apparatus for measuring coefficient of restitution includes a holder for holding a spherical indenter, an ejection mechanism configured to eject the indenter held by the holder from the holder to a specimen, a speed measuring unit configured to measure an impact speed that is a speed of the indenter before the indenter impacts against the specimen, and a rebound speed that is a speed of the indenter after the indenter is rebounded from the specimen; and an arithmetic unit configured to calculate a coefficient of restitution that is a ratio of the rebound speed to the impact speed.

Disclosed is an apparatus for in-situ testing impact strength of a micro-structure, comprising: a flexible beam, one end of which being fixed; an impact mass block disposed at the other end of the flexible beam and configured to exert an impact on the micro-structure; and a locking member comprising a beam arm and a plurality of locking teeth, wherein the beam arm is perpendicular to the flexible beam and one end of the beam arm is fixed, and wherein the plurality of locking teeth are distributed at intervals along the beam arm, such that the other end of the flexible beam is engaged to one of the plurality of locking teeth when the flexible beam is loaded. A method for testing an impact strength of a micro-structure is also disclosed.

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.

A rotary shock testing machine including: a base; a shaft rotatable relative to the base; a test disc for holding one or more specimens to be tested, the test disc being rotatable with the shaft; an actuator for applying a rotation to the shaft and test disc; and a brake for applying a braking force to the test disc to subject the one or more specimens to a rotary shock.