Damage characterization in composite laminates with holes

Download

index.pdf

Date

2016

Author

Erartsın, Ozan

Metadata

Show full item record

Item Usage Stats

63
views

210
downloads

The main objective of this study is to conduct progressive failure analysis (PFA) of quasi-isotropic open-hole tension coupons that exhibit different failure patterns, namely brittle, pull-out, and delamination failure. Effect of delamination, in-situ strengths and degradation trend on failure patterns and loads are also investigated. Explicit finite element method is used for the study. Intra-laminar regions in the finite element model were modeled with 3-D continuum shell elements and interlaminar regions were modeled with 3-D interface elements with bilinear tractionseparation formulation of Cohesive Zone Method (CZM). Hashin’s failure criterion is used along with linear gradual damage evolution for intra-laminar regions. Results are compared with the open-hole tension tests that are conducted and taken from the literature. The results show that the model developed here gives satisfactory results in modeling the damage progression in open-hole tension laminates where three different failure patterns are involved. It is also observed that the delamination plays an important role for the damage progression in openhole tension laminates; thus, neglecting it may result in inaccurate prediction of damage patterns and overestimated ultimate loads.

Subject Keywords

Composite materials., Laminated materials., Surfaces (Technology)., Surfaces (Technology)

URI

http://etd.lib.metu.edu.tr/upload/12619785/index.pdf
https://hdl.handle.net/11511/25455

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Progressive failure analysis of composite shells Olcay, Yasemin; Darendeliler, Haluk; Department of Mechanical Engineering (2012) 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 ...
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 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...
Friction Factor Determination for Horizontal Two-Phase Flow Through Fully Eccentric Annuli Metin, C. Omurlu; Ozbayoglu, M. E. (Informa UK Limited, 2009-01-01) In this study, empirical friction factor correlations were developed for two-phase stratified-and intermittent-flow patterns through horizontal fully eccentric annuli. Two-phase flow hydraulics were investigated, and a flow pattern prediction model is proposed. The friction factor correlations were validated using experimental data collected at the multiphase flow loop METU-PETE-CTMFL. Two different geometrical configurations were used during experiments-that is, 0.1143 m inner diameter (ID) casing, 0.0571 ...
Automated image processing for scratch detection on specular surfaces Okbay, Volkan; Akar, Gözde; Department of Electrical and Electronics Engineering (2018) In industry, problems due to human error, mechanical flaws and transportation may occur; besides, they need to be detected in fast and efficient ways. In order to eliminate failure of human inspection, automated systems come in action, usually image processing involved. This thesis work, targets one common mass production problem on specular surfaces, i.e. scratch detection. To achieve this, we have implemented two different prototypes. The low-cost system is based on basic line detection, and the mid-end s...

Citation Formats

O. Erartsın, “Damage characterization in composite laminates with holes,” M.S. - Master of Science, Middle East Technical University, 2016.