Abstract: 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.

Abstract: 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.

Abstract: An evaluation method of an impact test and an impact tester are provided, capable of simply and accurately obtaining a natural frequency of the impact tester without adding a special machine for measuring the natural frequency of the impact tester. A personal computer includes, as a functional configuration, a data extraction section extracting from time-series data of force a data section for obtaining a natural frequency of an impact tester in a natural vibration analysis, and an analysis section carrying out a frequency spectrum analysis on the extracted data section. The data extraction section and the analysis section are respectively stored as a data extraction program and an analysis program in a memory.

Abstract: An evaluation method of an impact test and an impact tester are provided. A personal computer includes, as a functional configuration, a data extraction section extracting from time-series data of force a data section for obtaining a natural frequency of an impact tester in a natural vibration analysis, an analysis section carrying out a frequency spectrum analysis on the extracted data section, and a vibration waveform removal section removing a natural vibration waveform of the impact tester from force data. The data extraction section, the analysis section and the vibration waveform removal section are respectively stored as a data extraction program, an analysis program and a vibration waveform removal program in a memory.