応力緩和を利用したプラスチックの粘弾性定数簡便決定法 (. 解析)
A Simple Method to Determine the Viscoelastic Constants of Plastics by Stress Relaxation Measurements : I. Analysis
石橋達弥・蒲沢英喜・小奈 弘・吉田秀敏・手塚孝治
Ishibashi, Tatsuya / Gawasawa, Hideki / Ona, Hiroshi / Yoshida, Hidetoshi / Tezuka,Takaharu
This paper describes a convenient method to determine the viscoelastic properties of plastics based on short time relaxation tests after constant strain rate uniaxial compression. This method does not require special testing equipment, can be performed on ordinary material testing machines in the factory, and is based on an extension of the Testing Method for Compressive Properties of Plastics (JIS K 7208). In this paper, we analyze stress relaxation curves obtained from the tests mentioned above and discuss a simple method based on a 6-parameter viscoelastic model (3 parallel Maxwell elements). This model is based on an approximation of stress relaxation to a three story structure and an introduction of two differential coefficients at the initiation of stress relaxation. Furthermore, for wide application to a range of viscoelastic behavior, concrete reducible equations between two equivalent 6-parameter viscoelastic models are shown.
Key words: Stress Relaxation / Viscoelastic Constants of Plastics / Easy Determining Method / Equivalent 6-parameter Viscoelastic Model