scholarly journals Experimental and Simulation Study of Low-Velocity Impact on Glass Fiber Composite Laminates with Reinforcing Shape Memory Alloys at Different Layer Positions

2018 ◽  
Vol 8 (12) ◽  
pp. 2405 ◽  
Author(s):  
Min Sun ◽  
Mengzhou Chang ◽  
Zhenqing Wang ◽  
Hao Li ◽  
Xiaokun Sun

The effects of shape memory alloy (SMA) wires on the damage behavior of glass fibers/epoxy resin composite laminates for the case of low-velocity impact are investigated experimentally and numerically. In this work, the low-velocity impact tests of SMAs/glass fibers/epoxy resin composite laminates are carried out. The elastic–plastic theory was adopted to simulate the mechanical behavior of SMA during the loading stage. The three-dimensional (3D) Hashin failure criterion is adopted in Abaqus/Explicit to model the damage initiation of composite laminates. The cohesive damage model is introduced to control the interface element and model the delamination failure. Moreover, the impact damage mechanisms of composite laminates are analyzed based on the experimental and numerical simulation results. These results show that the numerical results obtained in the present study have a reasonably good agreement with the experimental results. In addition, it is also found that impact damages are mainly caused by matrix cracks and delamination with no perforation for the case of 32-J impact energy, and impact damages are mainly caused by fibers breakage with perforation for the case of 64-J impact energy.

2012 ◽  
Vol 583 ◽  
pp. 179-182
Author(s):  
Hai Ming Hong ◽  
Ming Li ◽  
Jian Yu Zhang ◽  
Yi Ning Zhang

A group of low-velocity impact tests on CCF300/QY8911 composite laminates were implemented by the low-velocity drop hammer test machine. The dent depth and the internal damage pattern with corresponding impact energy were studied, the internal delamination damage state of laminates after impact were observed through thermal layer exposing tests, and the mechanism of low-velocity impact delamination damage were discussed. The results indicated that there existed a significant inflection point in the curve of impact energy verse dent depth of CCF300/QY8911 composite material, which was also the transition point of different damage patterns. When the impact energy was smaller than the inflection energy, the damage pattern consisted mainly of matrix flaws and delamination damages, but when the impact exceeded the inflection energy, delamination damage hardly expanded while the expansion of damage was mainly fiber break.


2020 ◽  
pp. 073168442097064
Author(s):  
Di Zhang ◽  
Xitao Zheng ◽  
Jin Zhou ◽  
Wenxuan Zhang

A finite element (FE) model based on fiber kinking and a transversal fracture angle damage model with cohesive elements are proposed to simulate the low-velocity impact (LVI) and compression after impact (CAI), and build a relationship between LVI energy and CAI strength of composites. The proposed FE model is validated by a comprehensive experimental work conducted using a high strength carbon fiber/epoxy material system i.e. CCF300/BA9916II and underwent LVI and CAI experimentation.  The relative errors between numerical and experimental results of LVI damage area, maximum impact force, impact time, as well as CAI strength are less than 5%. The FE analysis results of LVI show that the dominant damage mode is delamination, and the CAI results demonstrate a brittle behavior with almost no loss of stiffness before failure. It is further deduced that the relationship of LVI energy and damage induced is directly proportional initially; however, after a threshold level of impact energy, the curve turns horizontal so that the increase in further impact energy does not increase the damage area substantially. A similar relationship is developed between impact energy and CAI strength.


2020 ◽  
pp. 096739112093818
Author(s):  
Naseer H Farhood ◽  
Saravanan Karuppanan ◽  
Hamdan H Ya ◽  
MTH Sultan

Recently, the incorporation of several different types of fibers into a single matrix has led to the development of superior hybrid composite properties at a cheaper cost. Fiber hybridization is one of the active strategies to toughen composites and improve impact damage resistance. However, the extraordinary high strength and stiffness of the carbon fiber as well as its lower damage tolerance make it more susceptible under the impact loading. This article mainly aims to improve impact damage resistance of carbon fiber pipes through fiber hybridization strategy with glass fibers under low-velocity impact. The composite pipes reinforced with thin internal liner of high-density polyethylene were fabricated through filament winding technology. Eight pipe configurations with different stacking sequences and fiber content ratios with a constant winding angle of [Formula: see text] were fabricated and tested under impact energies, 50 and 100 J. The damage characterization was evaluated using the optical imaging and mechanical micrograph sectioning technique. Results indicate that the hybrid configurations showed better energy absorption than reference carbon fibers specimen under 50 J impact energy. Specifically, specimens with glass fibers on the exterior side and alternative configuration of carbon–glass fibers showed better impact resistance with less damage observed. Meanwhile, the specimens with glass fiber on the exterior side suffered from extreme damage with increase in the energy absorption and maximum displacement for both fiber content ratios under 100 J of impact energy.


2018 ◽  
Vol 53 (1) ◽  
pp. 3-17 ◽  
Author(s):  
J Jefferson Andrew ◽  
Sivakumar M Srinivasan ◽  
A Arockiarajan

This paper aims to investigate the effect of homogenous and hybrid external patches based on plain weave woven glass and Kevlar fabric on low velocity impact and quasi-static tensile after impact response of adhesively bonded external patch repairs in damaged glass/epoxy composite laminates. In all hybrid patches, the proportion of Kevlar and glass fibers were equal (i.e. 50% of Kevlar and 50% of glass by volume fraction), while lay-up configuration was different. This further enables to study the associated effect of hybridization and lay-up configuration on impact response of the repaired laminates. The intent of using hybrid external patches is to combine the excellent high displacement-to-failure property of Kevlar fiber as a ductile reinforcement with the superior mechanical property of glass fiber as a brittle reinforcement. The effect of glass/Kevlar content on impact response and tensile after impact response was investigated for various incident impact energy levels, such as 2, 4, 6, and 8 J. Results showed that hybridization and lay-up configurations of the external patches played a significant role on low velocity impact and quasi-static tensile after impact response of the repaired glass/epoxy specimens. Specimens repaired using intra-ply hybrid patches showed better impact properties and damage tolerance capability than that of the virgin and other repaired specimens. In specific, the use of intra-ply hybrid patches reduced the impact energy absorption by 10.17% in comparison to the virgin specimens at impact energy of 8 J.


2021 ◽  
Vol 11 (2) ◽  
pp. 584
Author(s):  
Guan Lu ◽  
Tianyu Zhu ◽  
Yiming Xu

At present, most of the research on low velocity impact of composite laminates focuses on load location and damage assessment. To provide further early warnings about structural impact damage, impact energy can be monitored and identified. For high strength composite laminates with variable thickness, in order to further accurately evaluate the impact energy, it is necessary to adopt more suitable dynamic load signal analysis and impact energy identification methods. Therefore, a new low velocity impact monitoring and identification method for composite plates with variable thickness is proposed. All impact sample signals collected by optical fiber sensor network are decomposed by whitening Empirical Mode Decomposition (EMD); the energy feature set is established according to the impact energy eigenvalue of sample signal; according to the first order component of signal decomposition, the thickness coefficient is determined and the energy feature set is modified to evaluate the actual impact energy. Meanwhile, combined with optical fiber sensing and signal processing technology, an impact energy monitoring system has been established, and the low velocity impact monitoring and identification experiments of composite laminates with variable thickness were carried out. The proposed energy identification method successfully identified 1–3 J impact energy with an average error of 4.82%, and the average error of large thickness area with low sensitivity was significantly reduced from 13.25% to 5.67%. The results show that the thickness coefficient correction method based on whitening EMD can evaluate the low velocity impact energy more accurately, and the thickness coefficient correction step significantly improves the recognition performance.


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