**5. Conclusion**

Notches with different forms and sizes are unavoidable in composite laminates to satisfy the needs of some design requirements. The stress developed around these notches reduces the load-bearing capacity of these composite structures. The accuracy of the analysis of these kinds of structures is based on the choice of an appropriate strategy. In the present investigation, DIC technique was used to the assessment of stress distribution taking place in laminates with different notch sizes loaded in tension. In addition, FEM is also used to validate the distribution of stresses obtained experimentally and investigate the tensile strength degradation in these laminated plates. It has been shown that the ultimate strength degradation and final damage mechanism that appear after the final failure are depending on the open hole size and strain distribution. One can see that the SCF and the damage zones increase and the perforated plate strength decreases with the increase in the hole size. Moreover, to improve the ultimate strength values, the DHS technique was used. DHS is introduced to these structures as a strategy to increase the ultimate strength as well as the weight of the structures. Based on the experimental results, the ultimate strength can be improved by introducing two circular auxiliary holes along the principal stress directions.

**179**

India

**Author details**

Abdelhak Khechai1

Mohamed-Ouejdi Belarbi3

*Strength Improvement and Stress Analysis of E-Glass Laminated Plates with Circular Notches…*

\*, Preetamkumar Marutrao Mohite2

2 Department of Aerospace Engineering, Indian Institute of Technology, Kanpur,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

3 Energy Engineering and Materials Laboratory, University of Biskra, Algeria

1 Civil Engineering Laboratory, University of Biskra, Algeria

\*Address all correspondence to: a.khechai@univ-biskra.dz

provided the original work is properly cited.

, Abdelouahab Tati3

and

*DOI: http://dx.doi.org/10.5772/intechopen.87089*

The authors declare no conflict of interest.

**Conflict of interest**

*Strength Improvement and Stress Analysis of E-Glass Laminated Plates with Circular Notches… DOI: http://dx.doi.org/10.5772/intechopen.87089*
