scholarly journals Geometric modelling of kink banding in laminated structures

2012 ◽  
Vol 370 (1965) ◽  
pp. 1827-1849 ◽  
Author(s):  
M. Ahmer Wadee ◽  
Christina Völlmecke ◽  
Joseph F. Haley ◽  
Stylianos Yiatros
Keyword(s):  
Mechanical Response ◽  
Laminated Composite ◽  
Kink Band ◽  
Unidirectional Composite ◽  
Band Formation ◽  
Key Features ◽  
Band Deformation ◽  
Underlying Mechanisms ◽  
Laminated Structures ◽  
Energy Principles

An analytical model founded on geometric and potential energy principles for kink band deformation in laminated composite struts is presented. It is adapted from an earlier successful study on confined layered structures that was formulated to model kink band formation in the folding of geological layers. This study's principal aim was to explore the underlying mechanisms governing the kinking response of flat, laminated components comprising unidirectional composite laminae. A pilot parametric study indicates that the key features of the mechanical response are captured well and that quantitative comparisons with experiments presented in the literature are highly encouraging.

scholarly journals Axial-Compressive Behavior, Including Kink-Band Formation and Propagation, of Singlep-Phenylene Terephthalamide (PPTA) Fibers

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
M. Grujicic ◽  
S. Ramaswami ◽  
J. S. Snipes ◽  
R. Yavari ◽  
C.-F. Yen ◽  
...  
Keyword(s):  
Detrimental Effect ◽  
Mechanical Response ◽  
Topological Defects ◽  
Kink Band ◽  
Coarse Grained ◽  
Computational Investigation ◽  
Band Formation ◽  
Longitudinal Tensile Strength ◽  
Kink Bands

The mechanical response ofp-phenylene terephthalamide (PPTA) single fibers when subjected to uniaxial compression is investigated computationally using coarse-grained molecular statics/dynamics methods. In order to construct the coarse-grained PPTA model (specifically, in order to define the nature of the coarse-grained particles/beads and to parameterize various components of the bead/bead force-field functions), the results of an all-atom molecular-level computational investigation are used. In addition, the microstructure/topology of the fiber core, consisting of a number of coaxial crystalline fibrils, is taken into account. Also, following our prior work, various PPTA crystallographic/topological defects are introduced into the model (at concentrations consistent with the prototypical PPTA synthesis/processing conditions). The analysis carried out clearly revealed (a) formation of the kink bands during axial compression; (b) the role of defects in promoting the formation of kink bands; (c) the stimulating effects of some defects on the fiber-fibrillation process; and (d) the detrimental effect of the prior compression, associated with fiber fibrillation, on the residual longitudinal-tensile strength of the PPTA fibers.

Measurement of cohesive law for kink-band formation in unidirectional composite

2016 ◽  
Vol 151 ◽  
pp. 1-10 ◽  
Author(s):  
D. Svensson ◽  
K.S. Alfredsson ◽  
U. Stigh ◽  
N.E. Jansson
Keyword(s):  
Kink Band ◽  
Unidirectional Composite ◽  
Cohesive Law ◽  
Band Formation

Modeling of the Effective Actuation Response of SMA-MAX Phase Composites With Partially Transforming NiTi

2013 ◽  
Author(s):  
Brian T. Lester ◽  
Dimitris C. Lagoudas
Keyword(s):  
Residual Stress ◽  
Martensitic Transformation ◽  
Mechanical Response ◽  
Extreme Environments ◽  
Element Model ◽  
Kink Band ◽  
Max Phase ◽  
Band Formation ◽  
Ceramic Phase ◽  
Stress States

Shape Memory Alloy (SMA) composites are being increasingly investigated to address a variety of engineering problems. An application of growing interest is an SMA-MAX phase ceramic composite for use in extreme environments. By joining these two constituents, it is intended that the martensitic transformation of the SMA phase may be used with the unique kinking behavior of the MAX phases to improve the composite response. One particular intended outcome of this utilization is the development of residual stress states in the composite. These residual stress states are generated due to the formation of irrecoverable strains resulting from the interaction of the inelastic mechanisms in the system. By tailoring this stress state, the improved mechanical response of the ceramic phase under compression may be taken advantage of. These residual stress states and their effect on the effective thermomechanical response of the composite are explored in this work. To this end, a finite element model of the composite is development. Specifically, a recent 3D phenomenological constitutive model of the SMA phase is incorporated to describe the effects of martensitic transformation and a constitutive assumption for the MAX phase response associated with kink band formation is introduced. An additional non-transforming NiTi phase is noted and the role of its constitutive response is considered. This model is used to study the micromechanics of the associated composite residual stress states. The influence of these residual stresses on the effective actuation response is then investigated and the on the associated composite behavior determined. Specifically, it is shown that the variation in inactive NiTi leads to an altered actuation response.

Micromechanics of kink band formation in open-hole fibre composites under compressive loading

2018 ◽  
Vol 149 ◽  
pp. 66-73 ◽  
Author(s):  
Vedad Tojaga ◽  
Simon P.H. Skovsgaard ◽  
Henrik Myhre Jensen
Keyword(s):  
Compressive Loading ◽  
Kink Band ◽  
Band Formation ◽  
Fibre Composites ◽  
Open Hole

A Spectral Finite Element Model for Wave Propagation Analysis in Laminated Composite Plate

2006 ◽  
Vol 128 (4) ◽  
pp. 477-488 ◽  
Author(s):  
A. Chakraborty ◽  
S. Gopalakrishnan
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Shear Deformation ◽  
Mechanical Response ◽  
Laminated Composite ◽  
Wave Number ◽  
Single Element ◽  
Element Formulation ◽  
Frequency Wave ◽  
Spectral Finite Element

A new spectral plate element (SPE) is developed to analyze wave propagation in anisotropic laminated composite media. The element is based on the first-order laminated plate theory, which takes shear deformation into consideration. The element is formulated using the recently developed methodology of spectral finite element formulation based on the solution of a polynomial eigenvalue problem. By virtue of its frequency-wave number domain formulation, single element is sufficient to model large structures, where conventional finite element method will incur heavy cost of computation. The variation of the wave numbers with frequency is shown, which illustrates the inhomogeneous nature of the wave. The element is used to demonstrate the nature of the wave propagating in laminated composite due to mechanical impact and the effect of shear deformation on the mechanical response is demonstrated. The element is also upgraded to an active spectral plate clement for modeling open and closed loop vibration control of plate structures. Further, delamination is introduced in the SPE and scattered wave is captured for both broadband and modulated pulse loading.

Dynamic Behavior of Fiber Reinforced Composites Under Multiaxial Compression

1999 ◽  
Author(s):  
Kenji Oguni ◽  
G. Ravichandran
Keyword(s):  
Failure Mode ◽  
Kink Band ◽  
Fiber Reinforced Composites ◽  
Fiber Direction ◽  
Strain Rates ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Band Formation ◽  
Multiaxial Compression ◽  
Axial Splitting

Abstract Results from an experimental investigation on the mechanical behavior of a unidirectional reinforced polymer composite with 50% volume fraction E-glass/vinylester under uniaxial and proportional multiaxial compression are presented. Specimens are loaded in the fiber direction using a servo-hydraulic material testing system for low strain rates and a Kolsky (split Hopkinson) pressure bar for high strain rates, up to 3000 s−1. The results indicate that the compressive strength of the composite increases with increasing levels of confinement and increasing strain rates. Post-test optical and scanning electron microscopy is used to identify the failure modes. The failure mode that is observed in unconfined specimen is axial splitting followed by fiber kink band formation. At high levels of confinement, the failure mode transitions from axial splitting to kink band formation and fiber failure. Also, a new energy based analytic model for studying axial splitting phenomenon in unidirectional fiber-reinforced composites is presented.

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