PSI - Issue 71

M. Mohan Kumar et al. / Procedia Structural Integrity 71 (2025) 333–339

339

Table 2. Test and FEA Deflections results comparison up to 100 % DLL for One Wheel Landing load case

LH Wing

LH Wing

MLG Spar Displacement

Load (%)

TE

LE

TE

LE

X

Z

FEA Test

FEA Test

FEA Test

FEA Test

FEA Test

FEA Test

10 0.67 0.48 0.63 0.50 -0.62 -0.42 -0.61 -0.39 0.51 0.24 0.33 0.18 20 1.34 0.88 1.26 0.88 -1.23 -0.77 -1.22 -0.75 1.02 0.62 0.67 0.33 30 2.01 1.38 1.90 1.35 1.85 -1.28 -1.83 -1.25 1.53 0.82 1.01 0.51 40 2.68 1.84 2.53 1.77 -2.246 -1.80 -2.44 -1.70 2.04 1.08 1.35 0.69 50 3.35 2.32 3.16 2.17 -3.08 -2.24 -3.05 -2.18 2.55 1.51 1.69 0.87 60 4.02 2.82 3.79 2.64 -3.70 -2.79 -3.66 -2.68 3.06 1.74 2.02 1.01 70 4.69 3.17 4.42 2.96 -4.31 -3.19 -4.27 -3.1 3.57 2.22 2.36 1.14 80 5.36 3.75 5.06 3.59 -4.93 -3.82 -4.88 -3.73 4.08 2.83 2.70 1.34 90 6.03 4.25 5.69 3.99 -5.54 -4.30 -5.49 -4.17 4.59 3.00 3.04 1.52 100 6.70 4.77 6.32 4.52 -6.16 -4.76 -6.10 -4.70 5.10 3.20 3.38 1.68

6. Conclusions In this study, the finite element method was employed to evaluate whether the structural design of the composite wing for a two-seater trainer aircraft meets the strength requirements specified by airworthiness regulations under Design Limit Loads (DLL). The finite element analysis (FEA) results were validated through full-scale static testing of the wing, and the findings were as follows: ● The static strength test for the composite wing, subjected to 100% DLL for the one-wheel landing case, was successfully completed. ● The wing demonstrated the ability to support the limit loads without experiencing detrimental or permanent deformation, as evidenced by the deflection values returning close to zero during the unloading process. ● The finite element analysis results were generally consistent with the experimental data, confirming the validity of the FEA results, although some discrepancies at certain locations may be attributed to conservative assumptions in the finite element model, such as the omission of joining layers or joggles in the skin/foam. ● Strain measurements for CFRP and GFRP materials during the test were well within the allowable strain limits of 3500 με and 5500 με which are for DLL. Acknowledgements Authors would like to thank Head, Structural Integrity Division (SID) & Advanced Composites Division (ACD) and Director, CSIR-NAL, for their support and encouragement during the course of this work and also for all those who have contributed directly or indirectly to this work. References DU Chunzhi, FU Boyu, QIU Zhihao. 2019.Design and finite element analysis of composite wing for a low speed aircraft. Journal Of Machine Design; 36(S2):55-58. Smith, Howard W.1988. Static test of an ultralight airplane. Journal of Aircraft; 25(1):37-40.10.2514/6.1986-2600. Wang Tong, Wu Zhen.2011. Finite element analysis for simulate composite wing of X model aircraft. Journal of Shenyang Aerospace University; 28(05):48-51. Zhang W, Yao L J, Tong X Y. 2011. Structural Design and Testing of Small Ultralight Solar-Powered Unmanned Aerial Vehicle. Advanced Materials Research; 317-319:227-230.10.4028/www.scientific.net/AMR.317-319.227.