Free material stiffness design of laminated composite structures using commercial finite element analysis codes

2014 ◽  
Vol 51 (5) ◽  
pp. 1097-1111 ◽  
Author(s):  
Søren Randrup Henrichsen ◽  
Esben Lindgaard ◽  
Erik Lund
Author(s):  
Subhasankar Dwibedi

Abstract Composite materials have been widely used in industries for several years owing to their capability to perform better than homogeneous isotropic materials. Numerical tools like finite element method are efficiently used for analysis of structures made of composite materials. However, for complex shapes or geometries of structures, it becomes uneconomical (computational resource wise) to use Rayleigh-Ritz based finite element analysis. An unique Trefftz based finite element has been developed in this article to efficiently fill the gap in the above mentioned scenario. Hybrid-Tefftz finite element method’s flexibility to use arbitrary shaped elements comes handy in modelling complex geometries. The developed hybrid-Trefftz finite element approach has been used on symmetric angle-ply laminated composite plate and the obtained results have been compared with bench mark solutions. The present method proposes an approach for development of hybrid-Trefftz type finite elements, by which analysis of antisymmetric structures is also possible, an area of research which has been less explored by such approach as revealed from survey of available open literature.


Author(s):  
C L Chow ◽  
F Yang

In this study, a method of finite element analysis is presented to examine the three-dimensional inelastic behaviour of fibre-reinforced composite laminates with damage. The constitutive model for the characterization of mechanical responses of non-linear composite materials to damage that was proposed recently by the authors is employed. The formulation of the elastic damage stress-strain relationship in incremental form is first developed and then incorporated within the context of the displacement-based finite element procedure. Solution of the non-linear equilibrium equations is obtained with the modified Newton—Raphson iteration technique. Numerical implementation of the stress calculation is discussed in detail. Results predicted using the present finite element program for uniaxial off-axis tensile loading of unidirectional graphite/epoxy composite laminates show satisfactory agreement with those obtained from experiments. Other results describing the development of damage zones, the inelastic effect on stress distributions and material property variations due to damage in cross-ply laminated composite structures are also examined and discussed.


2015 ◽  
Vol 815 ◽  
pp. 49-53
Author(s):  
Nur Fitriah Isa ◽  
Mohd Zulham Affandi Mohd Zahid ◽  
Liyana Ahmad Sofri ◽  
Norrazman Zaiha Zainol ◽  
Muhammad Azizi Azizan ◽  
...  

In order to promote the efficient use of composite materials in civil engineering infrastructure, effort is being directed at the development of design criteria for composite structures. Insofar as design with regard to behavior is concerned, it is well known that a key step is to investigate the influence of geometric differences on the non-linear behavior of the panels. One possible approach is to use the validated numerical model based on the non-linear finite element analysis (FEA). The validation of the composite panel’s element using Trim-deck and Span-deck steel sheets under axial load shows that the present results have very good agreement with experimental references. The developed finite element (FE) models are found to reasonably simulate load-displacement response, stress condition, giving percentage of differences below than 15% compared to the experimental values. Trim-deck design provides better axial resistance than Span-deck. More concrete in between due to larger area of contact is the factor that contributes to its resistance.


2011 ◽  
Author(s):  
David Fornaro

Finite Element Analysis (FEA) is mature technology that has been in use for several decades as a tool to optimize structures for a wide variety of applications. Its application to composite structures is not new, however the technology for modeling and analyzing the behavior of composite structures continues to evolve on several fronts. This paper provides a review of the current state-of-the-art with regard to composites FEA, with a particular emphasis on applications to yacht structures. Topics covered are divided into three categories: Pre-processing; Postprocessing; and Non-linear Solutions. Pre-processing topics include meshing, ply properties, laminate definitions, element orientations, global ply tracking and load case development. Post-processing topics include principal stresses, failure indices and strength ratios. Nonlinear solution topics include progressive ply failure. Examples are included to highlight the application of advanced finite element analysis methodologies to the optimization of composite yacht structures.


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