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A method for theoretical estimation of R-Curves is derived. At first, the general approach is determined using some essential assumptions. Then a model consisting of successive stages of discrete movements is introduced which in turn results to a recursive equation. By solving the derived equation, R-Curves can be calculated thereby using results from a simple tension test. A quantitative
investigation is then accomplished in mode I utilizing a case study on Aluminum Alloy AA 7075- T6. Calculated theoretical Curves are compared with experimental ones. It is observed that the two curves are
reasonably compatible. The anticipation of both curves for instability points are also compared showing a great extent of consistency.