Progressive failure analysis of composite shells

Olcay, Yasemin
The objective of this thesis is to investigate the progressive failure behavior of laminated fiber reinforced composite shell structures under different loading conditions. The laminates are assumed to be orthotropic and the first order shear deformation theory is applied. Three-node layered flat-shell elements are used in the analysis. To verify the numerical results obtained, experimental and analytical results found in literature are compared with the outputs of the study, and the comparison is found to have shown good agreement with the previous work. Rectangular graphite/epoxy composite laminates under transverse loading are analyzed through several boundary conditions and stacking sequences. Maximum stress criteria, Hashin’s criteria and Tsai Wu criteria are employed to detect the failure and progressive failure methodology is be implemented according to instantaneous degradation approach. First ply failure, final failure loads, corresponding deformations and failure patterns are presented and compared.


Experimental and numerical investigation of damage process in composite laminates under low-velocity impact
Topaç, Ömer Tanay; Çöker, Demirkan; Gürses, Ercan; Department of Aerospace Engineering (2016)
Damage sensitivity of composites under out-of-plane dynamic loading, and its limited detectability on a structure has long remained a prominent problem in industry. In this study, simulations are compared with the real-time damage formation scheme, with the aim of increasing confidence in failure predictions. Drop-weight impact experiments are carried out on a [0/90]_s CFRP beam laminate. Initiation and progression of damage, consisting of matrix cracks and delamination, are visualized via ultra-high-speed ...
Failure analysis of advanced composites under impact by cohesive zone method
Doğan, Oğuz; Parnas, Kemal Levend; Department of Mechanical Engineering (2013)
The main objective of this study is to investigate the delamination damage of laminated composites subjected to low velocity impact. Three-dimensional finite element analyses are conducted to determine delamination area, shape and location. The impact analysis is performed by using the explicit finite element method which uses the central difference rule to integrate the equations of motion through the time. The composite structures are modeled using eight-node solid elements. The critical interfaces betwee...
Progressive interlaminar failure analysis in composite missile structures
Bartan Kumbasar, Büşra; Kayran, Altan; Department of Aerospace Engineering (2016)
Interlaminar damage in composite structures is very crucial because it may cause splitting of the layers and lead to progressive failure of the whole structure. Delamination initiation and progression must be predicted accurately to aid the design of composites structures. Objective of the thesis is to investigate the interlaminar progressive failure behavior of the composite wing of a missile manufactured by twill composite by finite element analysis and tests. For this purpose, before the analyses and tes...
Finite element analysis and tests of composite beams with fiber bragg grating sensors under torsional load for structural health monitoring applications
Karataş, Cansu; Yaman, Yavuz; Department of Aerospace Engineering (2017)
In this thesis, feasibility of Fiber Bragg Grating sensors for Structural Health Monitoring applications of composite structures is studied. The method and essentials for the manufacturing process of composite beams with embedded Fiber Bragg Grating sensors are presented. Composite beams instrumented with surface bonded and embedded Fiber Bragg Grating sensors are tested under static torsional load. In addition, Finite Element Analyses of composite beams under torsional load is conducted using the commercia...
Determination of the bending twisting coupling potential of composite materials via digital image correlation and its implementation in wind turbine blades
Şener, Özgün; Kayran, Altan; Department of Aerospace Engineering (2017)
In this thesis study, the main objective is to investigate the effect of bending-twisting coupling in composite wind turbine blades on the load alleviation, power generation and structural performance of the wind turbine system. For this purpose, experimental and numerical study is initially conducted to determine the bend-twist coupling potentials of composite materials. Bending-twisting behavior of composite materials are determined through a comparative study via the Digital Image Correlation (DIC) syste...
Citation Formats
Y. Olcay, “Progressive failure analysis of composite shells,” M.S. - Master of Science, Middle East Technical University, 2012.