METHOD AND APPARATUS FOR DETERMINING THE FUNDAMENTAL VISCOELASTIC PROPERTIES OF A MATERIAL

摘要

An apparatus for determining the basic viscoelastic properties of a viscoelastic material includes a means for applying a torsional stress to a viscoelastic material, a means for measuring the relaxation of the torsional stress over time and converting this relaxation ability to a representative waveform, and a portion of the waveform. Processing means for determining basic viscoelastic properties dependent on the frequency of the viscoelastic material based on the shape. Preferably, said processing means comprises a first dedicated processor for generating a digital waveform of said waveform, and a second general processor, such as an IBM compatible microcomputer, for determining basic viscoelastic properties from a portion of the digital waveform. For convenience in automating the determination of the basic viscoelastic properties of the test material, after the first processor examines the waveform, it is stopped if the digital waveform is more irregular than the expected waveform for the torsionally stressed viscoelastic material. A method for determining the basic viscoelastic properties of a viscoelastic material includes applying torsional stress to a viscoelastic material, measuring the relaxation of the torsional stress over time, and converting such relaxation stress to a representative analog waveform, digitizing the analog waveform. Generating a representative digital waveform, and determining basic viscoelastic properties dependent on the frequency of the viscoelastic material based on some shape of the representative digital waveform. To facilitate the automation of this method, the shape of the waveform is analyzed to detect the end of the experiment and whether the experiment is useful. Preferably, converting the torsional value based on the amplitude of the waveform into a shear relaxation coefficient value, such as multiplying the torsional amplitude by the geometrical coefficient of the experimental material, and the known Yagi / Maekawa approximation techniques By the step of converting the shear stress coefficient value into the basic viscoelastic properties dependent on the frequency, the basic viscoelastic properties of the experimental material are determined.