According to one embodiment, an inspection apparatus determines an object to be in a first state when an intensity at a first frequency of a frequency characteristic is not less than a first threshold, and determines the object to be in a second state when the intensity at the first frequency is less than the first threshold. The frequency characteristic is generated based on a vibration of the object when the object is struck. The second state is different from the first state.

A high-speed tensile testing machine conducts a tensile test on a test piece by applying a test force to the test piece. The high-speed tensile testing machine includes a detection unit configured to detect a test period indicating a time from when the test piece starts to deform under action of the test force to when the test piece breaks, and a determination unit configured to determine validity of a test result of the tensile test, on the basis of the test period and natural vibration of the high-speed tensile testing machine. Specifically, in the case where the test period is a predetermined multiple or more of a specific cycle indicating a cycle of the natural vibration of the high-speed tensile testing machine, the determination unit determines that the test result of the tensile test is valid.

A test result evaluating method and a material tester are provided. A test result evaluating part includes a representative value calculating part that acquires a representative value of section data corresponding to one period of a natural vibration frequency from data of a time period representing a force applied to a test piece also including a natural vibration and a ratio calculating part that calculates a ratio between the representative value acquired by the representative value calculating part and a value based on an amplitude of the natural vibration. The representative value calculating part and the ratio calculating part are arranged in a test result evaluating part as programs realizing functions by operating an arithmetic operation device.

An apparatus for testing paving samples includes a base that includes a paving sample tray about the cabinet and configured for translation relative to the cabinet. A roller is configured for imparting compressive forces to a sample carried by the sample tray. An arm is configured for moving the roller from a stowed position to an in-use position where the roller contacts the sample. A cylinder assembly having a piston therein supplies pressure forces to the arm to move the arm from the stowed position to the in-use position, wherein a depth of travel of the arm is limited by the sample. As the sample is compressed, the depth of travel increases. A measurement device is in communication with the cylinder for determining an amount of travel of the arm to thus determine an amount of compression of the sample.

An apparatus for testing paving samples includes a base that includes a paving sample tray about the cabinet and configured for translation relative to the cabinet. A roller is configured for imparting compressive forces to a sample carried by the sample tray. An arm is configured for moving the roller from a stowed position to an in-use position where the roller contacts the sample. A cylinder assembly having a piston therein supplies pressure forces to the arm to move the arm from the stowed position to the in-use position, wherein a depth of travel of the arm is limited by the sample. As the sample is compressed, the depth of travel increases. A measurement device is in communication with the cylinder for determining an amount of travel of the arm to thus determine an amount of compression of the sample.

A method to determine a fatigue limit for a material. Form a test component including the material. Identify a resonant frequency of the component and an excitation frequency which causes the component to vibrate. Measure a response parameter of the component when excited at the excitation frequency. Test the component to determine its fatigue limit by sub-steps to: apply an excitation force to the component at the excitation frequency to cause vibration of the component; alter the applied excitation force at constant excitation frequency to maintain the response parameter constant; measure at least one of an input parameter and an output parameter; iterate the sub-steps to alter and measure until the first order, second order, or first and second order derivatives of the input parameter and/or output parameter exhibit a discontinuity. Repeat the steps for a different excitation frequency. The fatigue limit for the material includes all the identified discontinuities.

The invention discloses a method for in vitro testing of specimens, such as biomaterials, to obtain history-dependent, time-invariant functional materials properties using time-convolution and idempotent analysis. The purpose of the method is to measure these properties using a data processing without limitations of materials models, the properties linearity or material homogeneity.

Provided are a striking device and a natural frequency measuring device capable of simply and accurately measuring a natural frequency of a system including force detector. The striking device includes an arm capable of swinging around a spindle, and a steel ball arranged in an end part of the arm on a side opposite to the spindle. The spindle is supported by a supporting part capable of lifting up and down relative to a post erected on a magnet stand. A supporting part for supporting a supporting plate is arranged at a position in the post and above the supporting part. A permanent magnet is placed above the supporting plate. The steel ball falls down in an arc shape from a standby height position when the permanent magnet is removed.

A test result evaluating method and a material tester are provided. A test result evaluating part includes a representative value calculating part that acquires a representative value of section data corresponding to one period of a natural vibration frequency from data of a time period representing a force applied to a test piece also including a natural vibration and a ratio calculating part that calculates a ratio between the representative value acquired by the representative value calculating part and a value based on an amplitude of the natural vibration. The representative value calculating part and the ratio calculating part are arranged in a test result evaluating part as programs realizing functions by operating an arithmetic operation device.

Provided are a material testing machine and a gripping force detecting method that can easily judge whether a test piece is gripped with an appropriate gripping force by a gripper. A controlling section is connected to a FFT transforming section via a load cell; the FFT transforming section calculates a natural frequency of a system comprising a test piece and an upper gripper which is connected to a load cell based on a detected value of a force of the load cell. In addition, the controlling section is connected to a storing section which stores the natural frequency calculated by the FFT transforming section. Furthermore, the controlling section is also connected to a comparing section which compares the natural frequency calculated by the FFT transforming section and the natural frequency stored by the storing section before a test starts.