Numerical and Experimental Investigation on the Effect of Geometric Discontinuity on Frequency Response of Composite Lattice Conical Structures

الموضوعات :

M. R Zamani ¹ , M Zaretabar ²

1 - Mechanical Engineering Department, Malek-Ashtar University of Technology, Tehran, Iran
2 - Mechanical Engineering Department, Malek-Ashtar University of Technology, Tehran, Iran

تاريخ الإرسال : 18 الأحد , ذو الحجة, 1443 تاريخ التأكيد : 24 الثلاثاء , صفر, 1444 تاريخ الإصدار : 07 الخميس , جمادى الأولى, 1444

الکلمات المفتاحية: Composite lattice structure, Geometric discontinuity, Finite Element, Modal Analysis, Conical structure,

ملخص المقالة :

Composite structures are increasingly being used in various engineering structures such as automotive, aerospace, and civil structures due to their superior properties, namely, high strength-to-weight ratio, impact resistance, and durability. For the purpose of accessibility to other components and possibility of installation, aerospace structures encounters geometrical discontinuities which can lead to a complex structural analysis due to non-isotropic behavior. This paper aims to study the frequency response behavior of a composite lattice conical structure considering the effect of geometric discontinuity stiffened by a circular ring. The lattice structures are made of glass fiber reinforced polymers (GFRP) fabricated using filament winding method and cured in an autoclave. Numerical analysis and experimental modal testing was performed to obtain frequency response of the structures considering geometrical discontinuities. The results showed that the natural frequency values of structures with cutout in free-free boundary conditions are lower than those without cutout. Furthermore, comparing the mode shapes of structures indicated that these shapes were similar to each other and only some slight differences in discontinuity area were observed in some modes. Finally, the highest difference of numerical analysis results in structures with or without cutout was 2.61% while the highest difference of experimental analysis results in the structures was 3.73%. The greatest difference in the numerical and experimental analysis results is pertinent to the second mode in the structure without cutout is 15.64% and in the structure with cutout is 12.48%.

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