Constitutive Model for Shale Rock under High Strain Rates

M. Saad Rehan


Modeling the response of Shale rock towards impact loads imparted during hydraulic fracturing is essential in order to explain its strain rate sensitive behavior. In this paper, modified constitutive model, proposed by Zhu-Wang-Tang, is used to analyze the dynamic compressive properties of outcrop Shale rock of Khyber Pakhtunkhwa, Pakistan. The model comprises of multiple elastic and viscoelastic elements and is capable of predicting the dynamic behavior over a wide range of strain rates. Using the method of least squares, the model has been fitted to the experimental stress-strain curves obtained under the strain rates of the order of 102 s-1 and the parameters of the model are determined. It was found that the experimental and fitted curves were in good agreement.


Impact loads; Hydraulic Fracturing; Dynamic Compressive Properties; Viscoelastic Elements

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