PSI - Issue 54

Victor Rizov et al. / Procedia Structural Integrity 54 (2024) 475–481 Victor Rizov/ Structural Integrity Procedia 00 (2019) 000 – 000

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6

causes continuous reduction of the SERR.

1 2 / le le E E ratio plots (curve 1 – at / 1/8 1  l l , curve 2 – at / 1  l l

1/6

Fig. 5. Normalized SERR –

and curve 3 – at

/ 1  l l

1/4

).

Next, the ascendency of l l / 1 ratio over the SERR is investigated at three 1 2 / le le E E ratios. The plots of the corresponding dependences are displayed in Fig. 5. It is seen in Fig. 5 that the SERR reduces with growth of the ratio, l l / 1 . The same character has the ascendency of 1 2 / le le E E ratio over the SERR (Fig. 5). 4. Conclusions Delamination in a multilayered beam structure subjected to a mobile external force is studied. The force moves steadily along the upper surface of the structure. The SERR is inquired into. The analysis developed is based upon calculation of the complementary strain energy since the beam considered has non-linear viscoelastic behaviour. The beam behaviour under mobile force is treated by a non-linear viscoelastic mechanical model subjected to stress that depends on time. The material properties involved in this model change smoothly along the beam length. An examination of the SERR is done by the J -integral method. One of the momentous conclusions is that the SERR grows continuously with time under the mobile loading considered in this paper. It is also seen that the growth of the velocity of the motion of the external force results in reduction of the SERR. The research shows that the SERR reduces also when 1 1 / le re E E , 1 1 / le re   , 1 2 / le le E E and l l / 1 ratios grow. Ariga, K., Ji, Q., Hill, J. P., Bando, Y., Aono, M., 2012, Forming nanomaterials as layered functional structures toward materials nanoarchitectonics. NPG Asia Mater 4, 125-136. Broek, D., 1986. Elementary engineering fracture mechanics. Springer. Dolgov, N. A., 2005, Determination of Stresses in a Two-Layer Coating. Strength of Materials 37, 422-431. Dolgov, N. A. 2016, Analytical Methods to Determine the Stress State in the Substrate – Coating System under Mechanical Loads. Strength of Materials 48, 658-667. Freund, L.B., 1995, The stress distribution and curvature of a general compositionally graded semiconductor layer. J. Cryst. Growth 132 341-344. Hutchinson, J.W., Suo, Z., 1992, Mixed mode cracking in layered materials. Adv. Appl. Mech. 64, 804 – 810. Kim, J.S., Paik, K.W., Oh, S.H., 1999, The Multilayer- Modified Stoney’s Formula for Laminated Polymer Composites on a Silicon Substrate . J. References