scholarly journals Investigation of Quasi-Static Indentation Response of Inkjet Printed Sandwich Structures under Various Indenter Geometries

Materials ◽  
2017 ◽  
Vol 10 (3) ◽  
pp. 290 ◽  
Author(s):  
Vishwesh Dikshit ◽  
Arun Nagalingam ◽  
Yee Yap ◽  
Swee Sing ◽  
Wai Yeong ◽  
...  
Keyword(s):  
Sandwich Structures ◽  
Static Indentation ◽  
Indentation Response

scholarly journals Evaluation of quasi-static indentation response of superelastic shape memory alloy embedded GFRP laminates using AE monitoring

2021 ◽  
Vol 93 ◽  
pp. 106942 ◽  
Author(s):  
Luv Verma ◽  
J. Jefferson Andrew ◽  
Srinivasan M. Sivakumar ◽  
G. Balaganesan ◽  
S. Vedantam ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Static Indentation ◽  
Indentation Response

An analytical model for the response of carbon/epoxy-aluminum honeycomb core sandwich structures under quasi-static indentation loading

2017 ◽  
Vol 21 (6) ◽  
pp. 1930-1952 ◽  
Author(s):  
Abhendra K Singh ◽  
Barry D Davidson ◽  
Alan T Zehnder ◽  
Benjamin PJ Hasseldine
Keyword(s):  
Analytical Model ◽  
Sandwich Structures ◽  
Plate Theory ◽  
Ritz Method ◽  
Design Tool ◽  
Face Sheet ◽  
Total System ◽  
Honeycomb Core ◽  
Static Indentation ◽  
Aluminum Honeycomb

An analytical model is developed to predict the loading and unloading response, as well as the residual dent diameter and dent depth, of carbon/epoxy-aluminum honeycomb core composite sandwich structures undergoing quasi-static indentation loading. The model considers damage created using spherical indenters and is valid up to the barely visible external damage threshold. The initial low load regime (until the onset of core crushing) is modeled using a combination of local Hertzian indentation of an elastic half-space and small deflection plate theory of a circular plate on an elastic foundation. For loads above those required to cause core crushing, the model uses the Rayleigh-Ritz method of energy minimization with the total system energy determined using a combination of face sheet bending energy, face sheet membrane energy and work done to the core during both elastic deformation and crushing. Degraded face sheet properties are used in the model beyond the onset of face sheet delamination, which is predicted using Griffith’s energy criterion. The model is validated using experimental results for sandwich structures consisting of quasi-isotropic 8- (thin) and 16- (thick) ply carbon/epoxy face sheets and aluminum honeycomb cores. The results show that the overall mechanics of the model are fundamentally correct and reflective of physical behavior. Thus, in its present form the model shows promise as a preliminary design tool.

Multi-Level Modeling of Low Velocity, Low Energy Impact on Metal-Skinned Sandwich Structure

2006 ◽  
Author(s):  
B. Castanie´ ◽  
C. Bouvet ◽  
J.-J. Barrau ◽  
P. Thevenet
Keyword(s):  
Phenomenological Study ◽  
Sandwich Structures ◽  
Element Model ◽  
Honeycomb Structure ◽  
Low Energy ◽  
Low Velocity ◽  
Uniform Compression ◽  
Energy Impact ◽  
Nonlinear Springs ◽  
Static Indentation

The research objective is to model the low velocity/low energy impact on sandwich structures with metallic skins. A progressive approach is carried out by considering first the honeycomb core alone, then static indentation on sandwich structures and finally a dynamic analysis. During the first step, a phenomenological study of the behavior of honeycomb subjected to crushing is completed. It appears that local rotations and cell edges plays an important role in the crushing phenomenon. It is then possible to propose a simple analytical model able to represent the indentation of honeycomb alone for various indenter geometries by modelling only the cell edges behavior. The compression law of the cell edges is identified by a basic uniform compression test. This key-idea is then used to create a finite element model using a grid of nonlinear springs to represent the honeycomb structure. The contact law of static indentation tests of metal-skins Nomex™ honeycomb sandwich structures can thus be found numerically and agree well with the experiments. Finally, this contact law can be used to model dynamic impacts which demonstrates the static/dynamic equivalence for this range of impact and structures.

Quasi-static indentation response of pedestrian bridge multicellular pultruded GFRP deck panels

2016 ◽  
Vol 118 ◽  
pp. 307-318 ◽  
Author(s):  
L.S. Sutherland ◽  
M.F. Sá ◽  
J.R. Correia ◽  
C. Guedes Soares ◽  
A. Gomes ◽  
...  
Keyword(s):  
Pedestrian Bridge ◽  
Deck Panels ◽  
Static Indentation ◽  
Indentation Response

Static Indentation Response of H30 Foam ‐ an Experimental and Computational Study

2008 ◽  
Vol 4 (3) ◽  
pp. 255-266 ◽  
Author(s):  
V. Rizov ◽  
A. Mladensky
Keyword(s):  
Computational Study ◽  
Computer Code ◽  
Damage Resistance ◽  
Rigid Foam ◽  
Modeling Procedure ◽  
Static Indentation ◽  
Nonlinear Character ◽  
Indentation Tests ◽  
Overall Bending ◽  
Indentation Response

This article presents an approach for assessing the damage resistance of H30 rigid foam subjected to local static loading. The main goal of the experimental part of this paper is to obtain the loaddisplacement response of foam beam specimens under static indentation by steel cylindrical indentors for both loading (indentation) and unloading stages. The instant residual dent magnitude is also measured in the testing. The nonlinear character of the mechanical behavior and the formation of a residual dent (after unloading) are attributed to local crushing of the foam in the zone directly under the indentation area. A visual inspection of a lateral surface of the foam specimens after indentation tests revealed that the local damage underneath the indentor consists of crushed and highly compacted foam, while the rest of the specimen is almost undeformed. A two‐dimensional numerical model is developed to simulate the static indentation response using the ABAQUS computer code. No overall bending of the foam specimens is assumed. The finite element modeling procedure takes into account both physical and geometrical non‐linearities. In order to simulate the plastic part of the response, the model employs the *CRUSHABLE FOAM and *CRUSHABLE FOAM HARDENING options. The modeling procedure is capable of analyzing indentation as well as unloading of foam beam specimens. Thus, the instant residual dent can be predicted. Results generated by this model exhibit good correlation with indentation tests data, thus substantiating its validity.

scholarly journals Residual compression property and response of honeycomb sandwich structures subjected to single and repeated quasi-static indentation

2021 ◽  
Vol 60 (1) ◽  
pp. 404-417
Author(s):  
Hangyu Ye ◽  
Xiangjun Dai ◽  
Tianyu Yuan ◽  
Jilei Zhou ◽  
Jipeng Zhang ◽  
...  
Keyword(s):  
Sandwich Structures ◽  
Three Dimensional ◽  
Correlation Method ◽  
Image Correlation ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Governing Parameter ◽  
Honeycomb Sandwich ◽  
Static Indentation ◽  
Residual Compression

Abstract This paper investigated the response and residual compression properties of honeycomb sandwich structures subjected to single quasi-static indentation (QSI) and repeated QSI (RQSI). The damage depth after repeated low-velocity impact (LVI) was considered as the governing parameter during the QSI experiments. Three-dimensional digital image correlation method was applied to determine deformation of the front panels after LVI and QSI to describe damage to honeycomb structures. For specimens with the same depth, it is found that the residual strength of QSI was less than that of LVI and close to that of RQSI. Results indicated that it is more reasonable to describe the damage by volume than by depth.

Quasi-static indentation response of aramid fiber/epoxy composites containing nylon 66 electrospun nano-interlayers

2016 ◽  
Vol 47 (5) ◽  
pp. 960-977 ◽  
Author(s):  
Mostafa Goodarz ◽  
Hajir Bahrami ◽  
Mojtaba Sadighi ◽  
Saeed Saber-Samandari
Keyword(s):  
Composite Laminates ◽  
Visual Inspection ◽  
Back Side ◽  
Opposite Trend ◽  
The Matrix ◽  
Static Indentation ◽  
Promising Application ◽  
Force Displacement ◽  
Composite Properties ◽  
Indentation Response

In the last decade, polymer nanofibers have found promising application for improving through-thickness properties of structural composite laminates through interleaving. The main advantage of inserting nanofibers in conventional composites is making the matrix between the layers tougher. In this article, the benefits of using electrospun fibrous nano-interleaves in enhancing the quasi-static indentation response of aramid/epoxy laminated composites was investigated and the effect of variables of produced nano-interleaves including interleaf thickness (17.5, 35, and 70 µm) and stacking configuration (one-side, central, and two-side interleaving) on behavior of the nano-modified composites was investigated. The results indicate that force, displacement, absorbed energy, and stiffness of these composites are significantly affected by the presence of nano-interleaves. The optimum values were observed in the composites with 35 µm thickness of nano-interleave where three first parameters were higher than their reference values, but the stiffness value had opposite trend of other parameters. On the other hand, it can be seen that only asymmetrical (back-side indentation) stacking configuration lead to improving the composite properties. The visual inspection of the indentation damaged specimens reveals that thickness and stacking configuration of interleaves controls the size of damage.

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