PSI - Issue 1

Salem Cherif Sadek et al. / Procedia Structural Integrity 1 (2016) 234–241 Salem cherif Sadek / StructuralIntegrity Procedia 00 (2016) 000 – 000

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These curves show an increase in the values of the ratio ψ depending on θ until to 70 °. From this value there is a stability observed in mode 1 and 2.

12. Crack opening during buckling

We calculated the displacement Ux corresponding to the opening in the middle of the lips of the crack during buckling in mode 1. From this figure, it is found that for 2a/w ≤ 0.25 the opening of the crack  is constant. Exceed the value 0.25, increasing the distance  becomes sensitive.

2,30

2,07

  f (2a/w)

1,84

1,61

1,38

1,15

 x   ( m)

0,92

0,69

0,46

0,23

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 0,00

2a/w

Fig 11. Spacing  of the lips of the crack in buckling mode 1.

13. Conclusions We found that the variation of critical constraints is proportional to the crack length and inclination relative to the longitudinal axis of the panel. The critical stress decreases as the length of the longitudinal crack increases. It appeared also that the buckling strength may increase for a cracked panel for certain values of the inclination of the crack. A transverse crack is more stable in buckling than a longitudinal crack. Finally, we have shown that with the value of a rigidity of an uncracked panel (rigidity which can be estimated by considering the panel equivalent to a plate), it is possible to calculate critical loads for a cracked panel by means of functions of passage. . Brighenti R., 2005. Numerical buckling analysis of compressed or tensioned cracked thin plates , Vol.27, pp 265-276, Journal of engineering structures. Euler, L. 1993. Methodus inveniendi üneas curvas maximi minimive proprietate gaudentes. Oldfäther WA, ELLIS CA., Brown D.M., Isis, vol. 20, pp. 72-160, Bousquet, Lausanne and Geneva. Ghavami, K. and Khedmati, M. R. 2006. Numerical and experimental investigations on the compression behaviour of stiffened plates , Vol.62, pp 1087-1100, Journal of Constructional Steel Research. Madenci, E. and Guven I. 2006. The Finite Element Method and Applications in Engineering Using ANSYS , C.8, PP. 403-412, Springer, New York. Nathera, A.H.S. and al, 2011. Influence of crack parameters and loading direction on buckling behavior of cracked plates under compression , Basrah Journal for Engineering Science. Seifi, R. and al, 2011. Experimental and numerical studies on buckling of cracked thin-plates under full and partial compression edge loading , Vol.49, pp 1504-1516, Journal of thin-welled structures. Timoshenko S. and Gere, J. M. 1961. Theory of elastic stability . McGraw-Hill, New York. References