Interfacial delamination crack profile estimation in polymer foam-cored sandwich composites

2019 ◽  
Vol 189 ◽  
pp. 635-643 ◽  
Author(s):  
Nilanjan Mitra ◽  
AlakKumar Patra ◽  
Shyamal Mondal ◽  
Prasanta Kumar Datta
Keyword(s):  
Sandwich Composites ◽  
Polymer Foam ◽  
Delamination Crack ◽  
Interfacial Delamination ◽  
Profile Estimation ◽  
Crack Profile

Interfacial delamination in glass-fiber/polymer-foam-core sandwich composites using singlemode–multimode–singlemode optical fiber sensors: Identification based on experimental investigation

2017 ◽  
Vol 22 (1) ◽  
pp. 40-54 ◽  
Author(s):  
Nilanjan Mitra ◽  
Alak K. Patra ◽  
Satya P Singh ◽  
Shyamal Mondal ◽  
Prasanta K Datta ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Side Surface ◽  
Cost Effective ◽  
Fiber Optic Sensor ◽  
Sandwich Composite ◽  
Foam Core ◽  
Sandwich Composites ◽  
Strain Sensing ◽  
Polymer Foam ◽  
Interfacial Delamination

Identification of interfacial delamination in the glass fiber/polymer-foam-core sandwich composites is difficult if the delamination does not propagate to the side surface of the specimen. However, these damages may eventually lead to compromising the sandwich composite structural component. A cost-effective novel embedded fiber optic sensor is being proposed in this manuscript, which works on the principle of multimode interference, to perform distributed sensing of interfacial delamination within the sandwich composites while in service. Even though this easy to use methodology has been used to identify interfacial delamination, this methodology can also be used for different other types of interfacial/interlaminar distributed strain sensing of samples under mechanical as well as thermal loads.

scholarly journals Analyses of Deformation in Viscoelastic Sandwich Composites Subject to Moisture Diffusion

2008 ◽  
Author(s):  
Nikhil P. Joshi ◽  
Anastasia H. Muliana
Keyword(s):  
Dimensional Stability ◽  
Structural Characteristics ◽  
High Strength ◽  
Moisture Diffusion ◽  
Peel Strength ◽  
Sandwich Composite ◽  
Foam Core ◽  
Sandwich Composites ◽  
Polymer Foam ◽  
Effect Of Moisture

Sandwich composites with polymer foam core are currently used in load-bearing components in buildings and naval structures due to their high strength to weight and stiffness to weight ratios, excellent thermal insulation, and ease of manufacturing. During their service time, sandwich composites are exposed to various external mechanical and hygro-thermal stimuli. It is known that the constituent properties of the sandwich composites are greatly influenced by the temperature and moisture fields. Granville [1] conducted experiments to study the effect of moisture on structural, dimensional stability, weight gain and peel strength of sandwich composites. Morganti et al. [2] analyzed the effect of moisture on the dimensional stability of the sandwich composites and concluded that moisture affects the physical behavior of the composite directly by modifying its structural characteristics such as matrix degradation and microcracks between fiber and matrix etc. However, the effect of moisture on the deformations in the sandwich composite with the viscoelastic foam cores has not yet been studied. The time-dependent response of the sandwich composite (due to the viscoelastic foam core) is aggravated in the moist environment conditions. Thus, it becomes necessary to analyze the effect of moisture on the overall response of the sandwich composites.

Analysis on fracture behaviour of stitched foam sandwich composites using interlaminar tension test

2021 ◽  
pp. 109963622110631
Author(s):  
Shiyong Sun ◽  
Xinling Wang ◽  
Jianping Liang ◽  
Rui Yang ◽  
Yanguang Zhao
Keyword(s):  
Energy Absorption ◽  
Ultimate Load ◽  
Fracture Behaviour ◽  
Sandwich Composites ◽  
Extended Finite Element ◽  
Moulding Process ◽  
Interfacial Delamination ◽  
Tension Tests ◽  
The Face ◽  
Transfer Moulding

Sandwich composites are susceptible to interfacial delamination, owing to the mismatches in the material properties between the face sheets and core. Previous studies have shown that stitching can improve the performance of sandwich composites. In this study, an analysis approach was developed to investigate the fracture behaviour of stitched foam sandwich composites. The stitched foam sandwich composites were manufactured by a vacuum-assisted resin transfer moulding process. Interlaminar tension tests revealed the effects of the linear thread density on the failure mechanisms of the stitched foam sandwich composites. Asymmetric double cantilever beam tests were performed to investigate the influences of the stitch thread reinforcement on the fracture behaviour. An analytical approach combining extended finite element method and nonlinear spring elements was proposed to predict the failure behaviour of the stitched sandwich composites. Experiment and simulation approaches were employed to investigate the influences of the stitch parameters (stitch pitch and linear thread density) on the ultimate load and energy absorption. The results show that stitched method can significantly enhance the mechanical properties of sandwich composites. The energy absorption and ultimate load values of the specimens tend to increase with an increase in the linear thread density or a decrease in the stitch pitch.

Reconstruction of complex shaped crack from ECT signals based on a fast forward solver using an advanced multi-media element

2020 ◽  
Vol 64 (1-4) ◽  
pp. 621-629
Author(s):  
Yingsong Zhao ◽  
Cherdpong Jomdecha ◽  
Shejuan Xie ◽  
Zhenmao Chen ◽  
Pan Qi ◽  
...  
Keyword(s):  
Coefficient Matrix ◽  
Crack Edge ◽  
Numerical Accuracy ◽  
Gauss Point ◽  
Current Testing ◽  
Efficient Simulation ◽  
Shaped Crack ◽  
Multi Media ◽  
Profile Reconstruction ◽  
Crack Profile

In this paper, the conventional database type fast forward solver for efficient simulation of eddy current testing (ECT) signals is upgraded by using an advanced multi-media finite element (MME) at the crack edge for treating inversion of complex shaped crack. Because the analysis domain is limited at the crack region, the fast forward solver can significantly improve the numerical accuracy and efficiency once the coefficient matrices of the MME can be properly calculated. Instead of the Gauss point classification, a new scheme to calculate the coefficient matrix of the MME is proposed and implemented to upgrade the ECT fast forward solver. To verify its efficiency and the feasibility for reconstruction of complex shaped crack, several cracks were reconstructed through inverse analysis using the new MME scheme. The numerical results proved that the upgraded fast forward solver can give better accuracy for simulating ECT signals, and consequently gives better crack profile reconstruction.

HRR profile estimation using SLIM

2019 ◽  
Vol 13 (4) ◽  
pp. 512-521 ◽  
Author(s):  
Pia Addabbo ◽  
Augusto Aubry ◽  
Antonio De Maio ◽  
Luca Pallotta ◽  
Silvia Liberata Ullo
Keyword(s):  
Profile Estimation

Growth of single crystals of copper and their thermal profile estimation

Pramana ◽  
1986 ◽  
Vol 26 (2) ◽  
pp. 151-159 ◽  
Author(s):  
S K Khanna ◽  
M Sekar ◽  
A Michael David ◽  
K Govinda Rajan ◽  
P Bhaskar Rao
Keyword(s):  
Single Crystals ◽  
Thermal Profile ◽  
Profile Estimation
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