A method of strain and stress analysis for failure prediction in laminated composites

1995-01-01
Ardiç, E.S.
Bolcan, C.
Kayran, Altan
In this study, a method of strain and stress analysis is developed to predict the failure initiation in laminated composites containing two or more different kinds of laminae. In principle, the method developed in this study is similar to non-local elasticity, but the long-range interactions are considered on the strains instead of material moduli, and the method is developed and applied as a realistic and practical one. Firstly, the strain fields in each layer are determined separately and then these strain fields are used as input in-layer strains to obtain the strains and stresses in fibres and matrix in each layer individually. The principal strains and stresses in fibres and matrix are calculated in order to predict failure initiation. The method is applied to a sample problem and numerical results are presented as well as a comparison of the layer stresses with the results from the classical plate and shell theory.
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering

Suggestions

Development of a fast analytical method for prediction of part dynamics in machining stability analysis
Alan, Salih; Özgüven, Hasan Nevzat; Department of Mechanical Engineering (2009)
The objective of this study is to develop and implement practical and accurate methods for prediction of the workpiece dynamics during a complete machining cycle of the workpiece, so that FRFs of the workpiece can be used in chatter stability analysis. For this purpose, a structural modification method is used since it is an efficient tool for updating FRFs due to structural modifications. The removed mass is considered as a structural modification to the finished workpiece in order to determine the FRFs at...
A frequency domain nonparametric identification method for nonlinear structures: Describing surface method
Karaagacli, Taylan; Özgüven, Hasan Nevzat (Elsevier BV, 2020-10-01)
In this paper a new method called 'Describing Surface Method' (DSM) is developed for nonparametric identification of a localized nonlinearity in structural dynamics. The method makes use of the Nonlinearity Matrix concept developed in the past by using classical describing function theory, which assumes that nonlinearity depends mainly on the response amplitude and frequency dependence is negligible for almost all of the standard nonlinear elements. However, this may not always be the case for complex nonli...
Analytical solution of a crack problem in a radially graded FGM
Çetin, Suat; Kadıoğlu, Fevzi Suat; Department of Mechanical Engineering (2007)
The objective of this study is to determine stress intensity factors (SIFs) for a crack in a radially graded FGM layer on a substrate. Functionally graded coating with an edge crack perpendicular to the interface and a homogeneous substrate are bonded together. In order to make the problem analytically tractable, geometry is modeled as an FGM strip attached to a homogeneous layer. Introducing the elastic foundation underneath the homogeneous layer, an FGM coating on a thin walled cylinder can be modeled. At...
Development of test structures and methods for characterization of MEMS materials
Yıldırım, Ender; Arıkan, Mehmet Ali Sahir; Department of Mechanical Engineering (2005)
This study concerns with the testing methods for mechanical characterization at micron scale. The need for the study arises from the fact that the mechanical properties of materials at micron scale differ compared to their bulk counterparts, depending on the microfabrication method involved. Various test structures are designed according to the criteria specified in this thesis, and tested for this purpose in micron scale. Static and fatigue properties of the materials are aimed to be extracted through the ...
Development of de-icing and anti-icing solutions for aircraft on ground and analysis of their flow instability characteristics
Körpe, Durmuş Sinan; Özgen, Serkan; Department of Aerospace Engineering (2008)
In this thesis, development process of de-icing and anti-icing solutions and their flow instability characteristics are presented. In the beginning, the chemical additives in the solutions and their effects on the most critical physical properties of the solutions were investigated. Firstly, chemical additives were added to glycol and water mixtures at different weight ratios one by one in order to see their individual effects. Then, the changes in physical properties were observed when the chemicals were a...
Citation Formats
E. S. Ardiç, C. Bolcan, and A. Kayran, “A method of strain and stress analysis for failure prediction in laminated composites,” Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, pp. 43–51, 1995, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/45739.