scholarly journals Isogeometric analysis for simulation of progressive damage in composite laminates

2018 ◽  
Vol 52 (25) ◽  
pp. 3471-3489 ◽  
Author(s):  
Marco S. Pigazzini ◽  
Yuri Bazilevs ◽  
Andrew Ellison ◽  
Hyonny Kim
Keyword(s):  
Composite Laminates ◽  
Isogeometric Analysis ◽  
Composite Structures ◽  
Low Velocity Impact ◽  
Stiffened Panel ◽  
Progressive Damage ◽  
Low Velocity ◽  
New Class ◽  
Aerospace Applications ◽  
Post Impact

The increasing popularity of composite materials in aerospace applications is creating the need for a new class of predictive methods and tools for the simulation of progressive damage in laminated fiber-reinforced composite structures. The unique challenges associated with modeling damage in these structures may be addressed by means of thin-shell formulations which are naturally developed in the context of Isogeometric Analysis. In this paper, we further validate our recently developed Isogeometric Analysis-based multi-layer shell model for progressive damage simulations using experimental data for low-velocity impact on a 24-ply flat panel. The validation includes a careful comparison of delamination and matrix damage patterns predicted by the Isogeometric Analysis-based simulation and those obtained from post-impact non-destructive evaluation of the damaged coupon. The Isogeometric Analysis-based formulation is then deployed on two additional examples: a stiffened panel and a full-scale UAV wing, to demonstrate its suitability for, and ease of application to, typical aerospace composite structures.

scholarly journals Impact response in polymer composites from embedded optical fibers

2018 ◽  
Vol 52 (25) ◽  
pp. 3415-3427 ◽  
Author(s):  
Lorianne K Batte ◽  
Rani W Sullivan ◽  
Vipul Ranatunga ◽  
Kevin Brown
Keyword(s):  
Optical Fibers ◽  
Composite Laminates ◽  
Composite Structures ◽  
Impact Damage ◽  
Energy Levels ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Impact Surface ◽  
Post Impact

This study investigates the feasibility of using embedded optical fibers in polymer matrix composite laminates to characterize delaminations caused by low-velocity impacts with energies between 30 J and 50 J. Impact damage can occur in composite structures during manufacture, in-service, storage and routine maintenance. Because of their small size and light weight, optical fibers can be embedded in composite structures during the manufacture of composite parts, allowing the structure to be monitored for impact-induced delaminations without being removed from service. In this study, optical fibers are embedded in a grid configuration at four selected locations (one-third from impact surface, midplane, two-thirds from impact surface, and farthest ply from impact) in thick autoclave-cured graphite/epoxy laminates. Low-velocity impact testing is performed at four energy levels. Manufacturing procedures for embedding the optical fibers within the composite laminates are investigated. The strain distribution from the optical fibers is correlated with ultrasonic C-scans of the laminates in which they are embedded. X-ray computed tomography scan images are also compared to those from ultrasonic C-scans. Results indicate that embedded optical fibers can provide post-impact strain responses and delamination area from each embedded site within the impacted laminates.

scholarly journals A progressive damage model of composite laminates under low-velocity impact

2021 ◽  
Vol 39 (1) ◽  
pp. 37-45
Author(s):  
Junjie Zhou ◽  
Shengnan Wang
Keyword(s):  
Composite Laminates ◽  
Impact Force ◽  
Damage Model ◽  
Low Velocity Impact ◽  
Progressive Damage ◽  
Low Velocity ◽  
Damage Development ◽  
Velocity Impact ◽  
Progressive Damage Model ◽  
Matrix Damage

In this paper, a progressive damage model for studying the dynamic mechanical response and damage development of composite laminates under low-velocity impact was established. The model applied the Hashin and Hou failure criteria to predict the initiation of intra-laminar damage (fiber and matrix damage); a linear degradation scheme combined with the equivalent displacement method was adopted to simulate the damage development; a cohesive zone model with the bilinear traction-separation relationship was used to predict delamination. A user material subroutine VUMAT was coded, and the simulation analysis of carbon fiber reinforcement composite laminates subjected to 25 J impact was performed via commercial software ABAQUS. The predicted impact force-time curve, impact force-displacement curve, and damage distribution contours among the layers were in a good agreement with the experimental, which verified the proposed model. According to the simulation results, the fiber damage and matrix damage were analyzed, and the expansion of delamination was discussed.

Damage Characterization of Carbon and Glass Fiber Composite Plates Subjected to Low-Velocity Impact Using Thermography

2018 ◽  
Author(s):  
Khaled S. Al-Athel ◽  
Ahmed Alomari ◽  
Abul Fazal M. Arif
Keyword(s):  
Glass Fiber ◽  
Composite Laminates ◽  
Impact Damage ◽  
Fiber Composite ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Characterization ◽  
Post Impact

Composites are prone to delamination damage when impacted by low velocity projectiles because of the poor through-thickness strength. Therefore, some of the problems with composites are their poor impact damage resistance, weak post-impact mechanical properties, and the difficulty to inspect the impacted area by nondestructive means. Damage characterization of composite materials requires a scientific methodology, knowledge of polymeric materials, and direct field experience. In this work, low-velocity impact response of composite laminates was experimentally studied using drop-tower to determine the energy absorption. Three types of composites were used: carbon fiber, glass fiber, and mixed fiber composite laminates. In addition, these composites were characterized using thermography to quantify their post impact damage. It was found with the 3D temperature distribution that a strong correlation can be determined between the measured temperatures at the impact region with the quantification of the damage using thermal imaging with advanced mid-wave camera.

scholarly journals Low Velocity Impact Localization of Variable Thickness Composite Laminates

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6103
Author(s):  
Guan Lu ◽  
Yuchen Zhou ◽  
Yiming Xu
Keyword(s):  
Variable Thickness ◽  
Composite Laminates ◽  
Composite Structures ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Localization Performance ◽  
Fbg Sensors ◽  
The Impact ◽  
Impact Localization ◽  
Thickness Correction

Variable thickness composite laminates (VTCL) are susceptible to impact during use and may result in irreparable internal damage. In order to locate the internal impact damage of complex composite structures and monitor the impact signals of VTCL at the same time, a low velocity impact (LVI) monitoring system based on an optical fiber sensing network was constructed. Fiber Bragg grating (FBG) sensors are suitable for monitoring strain characteristics. By arranging FBG sensors on the laminate, we studied the spectrum analysis and localization of the impact signal collected by a FBG demodulator at constant temperature. The prior knowledge of variable thickness composite structures is difficult to obtain, and the multi-sensor dynamic monitoring is complex and difficult to realize. In order to locate the LVI of composite structures without prior knowledge, based on empirical mode decomposition (EMD), we proposed an impact localization method with zero-mean normalized cross-correlation (ZNCC) and thickness correction. The experimental results of LVI localization verification show that the ZNCC algorithm can effectively remove the temperature cross-sensitivity and impact energy influencing factors, and the thickness correction can reduce the interference of variable thickness characteristics on localization performance . The maximum localization error is 24.41 mm and the average error is 15.67 mm, which meets engineering application requirements. The method of variable-thickness normalization significantly improves impact localization performance for VTCL.

Correlation of Dent Depth to Maximum Contact Force and Damage of Composite Laminates

2014 ◽  
Vol 627 ◽  
pp. 353-356
Author(s):  
Z. Shen ◽  
Y.G. Xu ◽  
Andreas Chrysanthou
Keyword(s):  
Contact Force ◽  
Static Loading ◽  
Composite Laminates ◽  
Composite Structures ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Maximum Contact ◽  
Dent Depth ◽  
Maximum Contact Force

A major concern affecting the efficient use of carbon fibre reinforced composite laminates in the aerospace industry is the low velocity impact damage which may be introduced accidentally during manufacture, operation or maintenance of the composite structures. It is widely reported that the contact behavior of composite laminates under low-velocity impact can be obtained under quasi-static loading conditions. This paper focuses on the study of the correlation of the dent depth to the maximum contact force and damage of composite laminates under quasi-static loading. Analytical and finite element simulation approaches were employed to investigate relations between the contact force and the dent depth. Experimental investigations on the correlation between dent depth, maximum contact force and damage include quasi-static indentation testing, optical and scanning electron microscopic examination of the damage under different loading levels. The effect of damage initiation and growth on the contact behaviour has been discussed. Results show that consistent correlations between the dent depth, maximum contact force and damage exist and can be predicted with the analytical and numerical approaches. Dent depth can be used as an engineering parameter in assessing the severity of damage for composite structures that are subjected to low-velocity impact. This may lead to the development of a cost-effective technique for the inspection and maintenance of composite structures in aerospace applications.

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