泥漿體應力鬆弛特性之實驗研究

Experimental Study on the Characteristics of Stress Relaxation of Mud Slurries

詹錢登(Chyan-Deng Jan) ； 郭峰豪(Feng-Hao Kuo) ； 郭啓文(Chi-Wen Kuo)

《農業工程學報》 55卷3期 (2009/09) Pp. 65-74

https://doi.org/10.29974/JTAE.200909.0006

摘要

在固定剪切率作用下，泥漿體的剪應力隨著受剪時間的增加而逐漸減小，最後趨向於定值（平衡狀態），此種流變特性稱爲“應力鬆弛現象”。本研究進行不同濃度泥漿體在不同商定剪切率條件下的流變實驗，分析不同泥漿體達到剪應力平衡的時間，並比較受剪開始時及達到平衡時之剪應力。分析結果顯示濃度較高之泥漿髓，其剪應力達到平衡之時間較長，而且開始受剪時與達到平衡時之剪應力差異也較大，此表示含砂濃度較高之泥漿體的應力鬆弛現象較爲明顯。本文進一步採用Toorman(l997)之應力鬆弛模式，推估出不同泥漿體之流變參數，並建立泥漿體中泥砂含量與流變參數之關係，以做爲未來分析泥漿體流動運動機制之參考。

關鍵字

泥漿髓 ； 流變特性 ； 應力鬆弛

並列摘要

The shear stress of the sheared mud slurry would decrease as the increase of shearing time, and gradually reach an equilibrium state, under a constant shearing rate. This rheological behavior is called ”stress relaxation”. A series of rheological experiments of different concentrated mud slurries were conducted to investigate the stress relaxation behavior in this study. The equilibrium time (the time to reach the shear stress at equilibrium state) of different concentrated slurries was analyzed, and the initial shear stress (the shear stress at the initial state for slurries just starting to be sheared) and equilibrium shear stress (the shear stress at the equilibrium state) were compared in this study. The results show that the sheared slurries with higher concentration took longer time to reach their equilibrium state, and their stress differences between initial and equilibrium state were also larger. This implies that the stress relaxation behavior of slurries with higher concentration is more obvious. Based on the experimental data, the rheological parameters of the stress relaxation model proposed by Toorman (1997) were calculated, and the relationships of rheological parameters and volumetric concentration of slurries were analyzed, for providing the reference to future analysis of slurries-flow mechanism.

並列關鍵字

Mud slurry ； Rheological property ； Stress relaxation