ISO 6721-8:2019 プラスチック—動的機械特性の決定—パート8：縦振動とせん断振動—波動伝播法 | ページ 2

Foreword

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This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical-chemical properties.

This second edition cancels and replaces the first edition (ISO 6721-8:1997), which has been technically revised. The main changes compared to the previous edition are as follows:

• the document has been revised editorially;
• normative references have been changed to undated.

A list of all parts in the ISO 6721 series can be found on the ISO website.

1 Scope

This document describes an ultrasonic wave propagation method for determining the storage components of the longitudinal complex modulus L* and the shear complex modulus G* of polymers at discrete frequencies typically in the range 0,5 MHz to 5 MHz. The method is suitable for measuring materials with storage moduli in the range 0,01 GPa to 200 GPa and with loss factors below 0,1 at around 1 MHz. With materials that have a higher loss, significant errors in velocity measurement are introduced through waveform distortion and can only be reduced using procedures that are outside the scope of this document.

The method allows measurements to be made on small specimens, typically 50 mm × 20 mm × 5 mm, or small regions of larger specimens or sheets. It is therefore possible to obtain information on the homogeneity or anisotropy (see 10.5) of modulus in a specimen.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 6721-1 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses: