Snap-through buckling analyses of composite shallow spherical shells

1999-10-01
Akkas, N
Toroslu, R
The purpose of this work is to present some numerical results on nonlinear, snap-through buckling of shallow spherical shells made of laminated composite materials under general static loading. Isotropic shells are covered as a special case of the general problem. A special-purpose finite-difference computer program has been developed. Moreover, the general-purpose computer program ANSYS has also been used. Effects of various material properties on the nonlinear behavior of the shells are investigated. One of the conclusions of the study is that ANSYS may yield erroneous results in some cases. Another conclusion is that the buckling curves of composite shallow spherical shells have a shape similar to that of the corresponding isotropic shell. This finding implies that the geometry of a shell may be an important factor in giving a characteristic shape to the buckling curve, at least for the shell parameters considered here.
MECHANICS OF COMPOSITE MATERIALS AND STRUCTURES

Suggestions

Buckling, postbuckling and progressive failure anaylses of composite laminated plates under compressive loading
Namdar, Ömer; Darendeliler, Haluk; Department of Mechanical Engineering (2012)
The aim of this thesis is to investigate buckling, post-buckling behaviors and failure characteristics of composite laminated plates under compressive loading with the help of finite element method and experiments. In the finite element analyses, eigen value extraction method is used to determine the critical buckling loads and nonlinear Riks and Newton-Raphson methods are employed to obtain post-buckling behaviors and failure loads. The effects of geometric imperfection amplitude on buckling and post-buckl...
Failure analysis of tapered composite structures under tensile loading
Çelik, Ozan; Parnas, Kemal Levend; Department of Mechanical Engineering (2016)
A three dimensional finite element modeling approach is used to evaluate the effects of preliminary design variables on the performance of tapered composite laminates under tensile loading. Hashin failure criteria combined with a progressive failure algorithm is used for in-plane failure mechanisms and cohesive zone method is used for out-of-plane failures. The modeling approach is validated by a comparison with experimental results from literature. The validated model is used to examine various design vari...
Numerical investigation of stiffened composite panel into buckling and post buckling under combined loading
Akay, Erkan; Yaman, Yavuz; Department of Aerospace Engineering (2015)
This thesis presents the investigation of buckling and post buckling behaviour of stiffened thin walled laminated composite aerospace structures subjected to combined in-plane axial and shear loadings. Due to the fact that the state of stress developing especially in the post-buckling stage is quite complicated under the combined loading, the necessary computational model is usually based on Finite Element Modelling (FEM). In this study, after verifying the FEM methodology and completing the sensitivity stu...
Forced vibration analysis of generally laminated composite beams using domain boundary element method
Ahmed, Zubair; Dağ, Serkan; Department of Mechanical Engineering (2018)
Forced dynamic response of generally laminated composite beam is analyzed by boundary element method. Static fundamental solutions are used as weight functions in the weighted residual statements. The use of static fundamental solutions gives rise to a new formulation named as Domain Boundary Element Method. Displacement field of the generally laminated composite beam is written in accordance with first order shear deformation theory and equations of motion are derived using Hamilton’s principle. Developed ...
Delamination analysis by using cohesive interface elements in laminated composites
Gözlüklü, Burak; Parnas, Kemal Levend; Department of Mechanical Engineering (2009)
Finite element analysis using Cohesive Zone Method (CZM) is a commonly used method to investigate delamination in laminated composites. In this study, two plane strain, zero-thickness six-node quadratic (6-NQ) and four-node linear (4-NL) interface elements are developed to implement CZM. Two main approaches for CZM formulation are categorized as Unified Mode Approach (UMA) and Separated Mode Approach (SMA), and implemented into 6-NQ interface elements to model a double cantilever beam (DCB) test of a unidir...
Citation Formats
N. Akkas and R. Toroslu, “Snap-through buckling analyses of composite shallow spherical shells,” MECHANICS OF COMPOSITE MATERIALS AND STRUCTURES, pp. 319–330, 1999, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/65863.