Portable internal friction measuring instrument and internal friction measurement method

A portable internal friction measuring instrument, comprising a closed cavity extending in an up-down direction, and the cavity including a sample fixture, a heating plate, a thermal barrier cover, an excitation assembly, and a vibration sensor arranged in the cavity, wherein the sample fixture is configured to clamp an upper end portion of a sample made in a form of a plate, the heating plate configured to heat a lower end portion of the sample, the thermal barrier cover enclosing the heating plate and the lower end portion of the sample, in order to form a local high-temperature region in the cavity,

• the excitation assembly is configured to drive, by means of mechanical toggling, the lower end portion of the sample to generate vibration, the excitation assembly comprising a vibration impeller having a rotation axis line that is parallel to a plane on which the sample is located in a plumb state and a horizontal surface, at least one protrusion being provided on an outer wall of the vibration impeller, wherein during rotation of the vibration impeller, a lower edge of the sample is intermittently toggled by the at least one protrusion to cause the lower end portion of the sample to generate vibration, the vibration sensor is configured to emit light to irradiate the sample and to receive light reflected from the sample, wherein a vibration amplitude of the sample is determined by measuring an angle difference between the emitted light and the reflected light so as to realize measurement of internal friction.