Robustness of Empirical Vibration Correlation Techniques for Predicting the Instability of Unstiffened Cylindrical Composite Shells in Axial Compression

Polymers

Edgars Labans¹  Jānis Andersons²  Kaspars Kalnins³  Eduards Skukis³  Olgerts Ozolins³  Gints Jekabsons³ 

[1] Faculty of Aerospace Engineering, Delft University of Technology, 2629HS Delft, The Netherlands;Institute for Mechanics of Materials, University of Latvia, 3 Jelgavas str., LV-1004 Riga, Latvia;Institute of Materials and Structures, Riga Technical University, 6A Kipsalas str., LV-1048 Riga, Latvia;

关键词: polymer composite;    buckling;    imperfection;    vibration correlation technique;    natural frequencies;   

DOI  :  10.3390/polym12123069

来源: DOAJ

【 摘 要 】

Thin-walled carbon fiber reinforced plastic (CFRP) shells are increasingly used in aerospace industry. Such shells are prone to the loss of stability under compressive loads. Furthermore, the instability onset of monocoque shells exhibits a pronounced imperfection sensitivity. The vibration correlation technique (VCT) is being developed as a nondestructive test method for evaluation of the buckling load of the shells. In this study, accuracy and robustness of an existing and a modified VCT method are evaluated. With this aim, more than 20 thin-walled unstiffened CFRP shells have been produced and tested. The results obtained suggest that the vibration response under loads exceeding 0.25 of the linear buckling load needs to be characterized for a successful application of the VCT. Then the largest unconservative discrepancy of prediction by the modified VCT method amounted to ca. 22% of the critical load. Applying loads exceeding 0.9 of the buckling load reduced the average relative discrepancy to 6.4%.

【 授权许可】

Unknown