Determination of KI in orthotropic laminates with double ended cracks using a single strain gage technique. (April 2016)

• Record Type: Journal Article
• Authors: Chakraborty, Debaleena; Murthy, K.S.R.K.; Chakraborty, D.
• Is Part Of: Theoretical and applied fracture mechanics. Volume 82(2016)
• Page Start: 96
• Page End: 106
• Publication Date: 2016-04
• Subjects: Orthotropic -- Strain gage -- Mode I SIF -- Optimal -- Double ended crack; Fracture mechanics -- Periodicals; 620.1126
• DOI: 10.1016/j.tafmec.2015.12.013
• Languages: English
• ISSNs: 0167-8442

Abstract

Highlights: A strain gage method for finding KI of internal cracked composite panel is proposed. The existence and importance of optimal gage locations is demonstrated. The effect of gage orientation on the measured KI is demonstrated. Abstract: Experimental determination of mode I stress intensity factor (SIF) K I in orthotropic composites is of significant importance. In this direction, single strain gage techniques that are developed for measurement of K I are based on the solutions of the single ended crack theories and those have also been tested only for single ended cracked orthotropic configurations. Although, certain limitations prevent straight forward application of these single ended crack solutions to the double ended configurations, the present investigation aims at demonstrating the use of such a single strain gage technique recently proposed by the authors to the configurations containing double ended cracks or internal cracks in orthotropic materials for the accurate measurement of K I . Importantly, the present investigation also proposes existence and determination of optimal strain gage locations in double ended cracked orthotropic plates for the accurate measurement of K I . Studies have also been carried out to understand the effect of change in geometry of the configuration on the optimal gage locations. The results of the present investigation have been observed to substantiate the theoretical formulations in terms of accurate determination of K I . Numerical results clearly show that the proposed single strain gage technique yields accurate values of K I when the gage is placed at an optimal gage location. On the contrary, highly erroneous values of K I are obtained when the gage is placed at non-optimal locations.