Buckling Behavior of Compression-Loaded Composite Cylindrical Shells with Reinforced Cutouts

Abstract

Results from a numerical study of the response of thin-wall compression-loaded quasi-isotropic laminated composite cylindrical shells with reinforced and un- an unexpected increase in the magnitude of local deformations and stresses in the shell and cause a reduction in the buckling load. Specific cases are presented that suggest that the orthotropy, thickness, and size of a cutout reinforcement in a shell can be tailored to achieve improved response characteristics.

Imperfection Insensitivity Analyses of Advanced Composite Tow-Steered Shells

“…6 However, this approach has also led to excessive conservatism, with a detrimental impact on structural and launch vehicle performance. Despite the history of poor correlation of measured and predicted buckling loads for compression-loaded shells, 7,8 the linear bifurcation buckling analyses performed for the tow-steered shells described above yielded results which correlated well with the associated test data. [3][4][5] In the present study, the impact of a wide range of geometric imperfections on the structural performance of the two tow-steered shells described above is assessed using linear finite element analyses.…”

Detection of branching points in noisy processes

“…This includes the specification of L U and L SC in Eqs. (14) and (15). Second, if the process depends on more than one process coordinate, the order of selection of τ out of θ may change the result.…”

“…The identification of these paths and the associated physical and mechanical background is essential to understand a mechanical system and to design it for a specific purpose. Branching points can be associated with mechanical effects such as local buckling in shell structures [8,14,24], multiple failure kinematics in structural collapse after blasting [13,21], initialization of subor super-harmonic vibrations [17] or even chaotic behavior [19]. Numerical approaches for respective investigations are provided, in particular, on the basis of finite element analysis [1,2].…”

Buckling and Failure of Compression-loaded Composite Cylindrical Shells with Reinforced Cutouts

“…27,28 The reinforcements investigated consisted of square-shaped, concentrically aligned lamina plies added to the shell-wall mid-surface. Three reinforcement sizes and three reinforcement thicknesses, including 1-ply-thick, 2-ply-thick, and 4-ply-thick reinforcements, were studied to identify the effects of reinforcement size and thickness on the deformation response and stress distribution in the shell.…”

“…However, a recent numerical study of the response of compression-loaded, laminated-composite shells with reinforced cutouts was presented by Hilburger and Starnes. 27,28 This work predicts that reinforcement can be placed around a cutout in a compression-loaded shell that will affect the local deformations and stresses near the cutout such that the onset of local buckling near the cut is retarded or suppressed, compared to the corresponding shell without cutout reinforcement. For some reinforcement configurations, the local buckling response is followed by a stable, local postbuckling response near the cutout and additional load can be applied to the shell before it undergoes a global collapse.…”