scholarly journals Simulations and Tests of Composite Marine Structures Under Low-Velocity Impact

2021 ◽  
Vol 28 (1) ◽  
pp. 59-71
Author(s):  
Zhaoyi Zhu ◽  
Xiaowen Li ◽  
Qinglin Chen ◽  
Yingqiang Cai ◽  
Yunfeng Xiong
Keyword(s):  
Composite Laminates ◽  
Impact Force ◽  
Low Velocity Impact ◽  
Back Side ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Area ◽  
Impact Performance ◽  
Composite Ship ◽  
The Impact

Abstract Due to their excellent performance, composite materials are increasingly used in the marine field. It is of great importance to study the low-velocity impact performance of composite laminates to ensure the operational safety of composite ship structures. Herein, low-velocity drop-weight impact tests were carried out on 12 types of GRP laminates with different layup forms. The impact-induced mechanical response characteristics of the GRP laminates were obtained. Based on the damage model and stiffness degradation criterion of the composite laminates, a low-velocity impact simulation model was proposed by writing a VUMAT subroutine and using the 3D Hashin failure criterion and the cohesive zone model. The fibre failure, matrix failure and interlaminar failure of the composite structures could be determined by this model. The predicted mechanical behaviours of the composite laminates with different layup forms were verified through comparisons with the impact test results, which revealed that the simulation model can well characterise the low-velocity impact process of the composite laminates. According to the damage morphologies of the impact and back sides, the influence of the different layup forms on the low-velocity impact damage of the GRP laminates was summarised. The layup form had great effects on the damage of the composite laminates. Especially, the outer 2‒3 layers play a major role in the damage of the impact and the back side. For the same impact energy, the damage areas are larger for the back side than for the impact side, and there is a corresponding layup form to minimise the damage area. Through analyses of the time response relationships of impact force, impactor displacement, rebound velocity and absorbed energy, a better layup form of GRP laminates was obtained. Among the 12 plates, the maximum impact force, absorbed energy and damage area of the plate P4 are the smallest, and it has better impact resistance than the others, and can be more in line with the requirements of composite ships. It is beneficial to study the low-velocity impact performance of composite ship structures.

Effect of Core Thicknesses on Impact Performance of Thermoplastic Honeycomb Core Sandwich Structure under Low-Velocity Impact Loading

2011 ◽  
Vol 471-472 ◽  
pp. 461-465
Author(s):  
Nurashikin Sawal ◽  
Md Akil Hazizan
Keyword(s):  
Impact Force ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Face Sheet ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Area ◽  
Impact Performance ◽  
Core Thickness ◽  
The Impact

Low-velocity impact test on sandwich panels composed of aluminum face sheets and thermoplastic honeycomb cores have been performed to characterize the impact performance as a function of core thickness and drop heights. Impact parameters like maximum impact force, impact energy and impact damage area were evaluated and compared. Consequent damages were inspected visually on the impact surface as well as the rear surface. The experimental results found that panels with thicker core exhibited higher impact force than thinner core counterparts, allowing the panel to absorbed more energy. Higher degree of impact damage can be observed at elevated drop heights as most of the damage took the form of local core crushing, face sheet buckling and debonding between the face sheet and core,. Resulting damage area were different according to the core thickness as thicker core prone to absorbed more energy that lead to more damage propagation.

scholarly journals Low Velocity Impact Assessment Of Flax And Kevlar-Flax Fibre Reinforced Polymer Laminates Using Experimental and Numerical Methods

2021 ◽  
Author(s):  
Benedict Lawrence Sy
Keyword(s):  
Impact Toughness ◽  
Composite Laminates ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Performance ◽  
Fibre Reinforced Polymer ◽  
The Cross ◽  
The Impact ◽  
Polymer Laminates

Flax/epoxy composite laminates were tested under low velocity impact loading, using passive Infra-Red thermography to monitor the damage evolution during the impact event. Two configurations were tested: unidirectional ([08F]S) and cross-ply ([(0/90)4F]S). The unidirectional laminate exhibited poor and brittle impact response. Conversely, the cross-ply laminate showed better impact performance with its energy penetration threshold three times higher than the unidirectional. Its impact toughness was also 2.5 times higher. Additional tests were conducted to evaluate the effect of hybridization with Kevlar®49. Test results showed significant improvement on the impact performance of the unidirectional flax/epoxy laminate. Hybridization increased its energy penetration threshold three times and impact toughness five times. Conversely, it reduced the penetration threshold of the cross-ply flax/epoxy laminate by 10%; however, it more than doubled the impact toughness. The impact toughness the Kevlar-Flax/epoxy laminates were slightly higher than those of aluminum and CFRP’s, making them sustainable alternatives for impact applications.

scholarly journals Low Velocity Impact Assessment Of Flax And Kevlar-Flax Fibre Reinforced Polymer Laminates Using Experimental and Numerical Methods

2021 ◽  
Author(s):  
Benedict Lawrence Sy
Keyword(s):  
Impact Toughness ◽  
Composite Laminates ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Performance ◽  
Fibre Reinforced Polymer ◽  
The Cross ◽  
The Impact ◽  
Polymer Laminates

Flax/epoxy composite laminates were tested under low velocity impact loading, using passive Infra-Red thermography to monitor the damage evolution during the impact event. Two configurations were tested: unidirectional ([08F]S) and cross-ply ([(0/90)4F]S). The unidirectional laminate exhibited poor and brittle impact response. Conversely, the cross-ply laminate showed better impact performance with its energy penetration threshold three times higher than the unidirectional. Its impact toughness was also 2.5 times higher. Additional tests were conducted to evaluate the effect of hybridization with Kevlar®49. Test results showed significant improvement on the impact performance of the unidirectional flax/epoxy laminate. Hybridization increased its energy penetration threshold three times and impact toughness five times. Conversely, it reduced the penetration threshold of the cross-ply flax/epoxy laminate by 10%; however, it more than doubled the impact toughness. The impact toughness the Kevlar-Flax/epoxy laminates were slightly higher than those of aluminum and CFRP’s, making them sustainable alternatives for impact applications.

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.

Compressive Strength of CCF300/QY8911 Composite Laminates with LVI Damage

2012 ◽  
Vol 583 ◽  
pp. 203-206
Author(s):  
Hai Ming Hong ◽  
Ming Li ◽  
Jian Yu Zhang ◽  
Yi Ning Zhang
Keyword(s):  
Compressive Strength ◽  
Impact Energy ◽  
Composite Laminates ◽  
Inflection Point ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Area ◽  
Compressive Performance ◽  
The Impact ◽  
Dent Depth

A series of low-velocity impact tests and residual compressive strength tests after impacts on CCF300/QY8911 composite materials were carried out to study the mechanism of compression failure of the laminates after low-velocity impact. The curves of impact energy verse dent depth and impact energy verse the damage area was obtained. And the residual compressive strength and stiffness after impact verse damage parameters were analyzed. The results showed that when the impact energy exceeded the inflection point, as the impact energy increased, the dent depth on the impacted surface of the laminates notably increased while the damage area of the internal layers merely increased slowly. If the impact energy was continued to increase, the expansion of the laminates' internal damage mainly consisted of fiber breaks. The main reason for the decrease in compressive performance of composite laminates was inside delamination between layers, while in the case in which impact energy exceeded the inflection point, there were no obvious changes in delamination damage area for different energy, so the residual compressive performance kept almost stable.

Low-velocity impact properties and finite element analysis of syntactic foam reinforced by warp-knitted spacer fabric

2016 ◽  
Vol 87 (16) ◽  
pp. 1938-1952 ◽  
Author(s):  
Chao Zhi ◽  
Hairu Long ◽  
Fengxin Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Syntactic Foam ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Element Analysis ◽  
Velocity Impact ◽  
Impact Performance ◽  
Spacer Fabric ◽  
The Impact

The aim of this research was to investigate the low-velocity impact properties of syntactic foam reinforced by warp-knitted spacer fabric (SF-WKSF). In order to discuss the effect of warp-knitted spacer fabric (WKSF) and hollow glass microballoon parameters on the impact performance of composites, eight different kinds of SF-WKSF samples were fabricated, including different WKSF surface layer structures, different spacer yarn diameters and inclination-angles, different microballoon types and contents. The low-velocity impact tests were carried out on an INSTRON 9250 HV drop-weight impact tester and the impact resistances of SF-WKSF were analyzed; it is indicated that most SF-WKSF specimens show higher peak impact force and major damage energy compared to neat syntactic foam. The results also demonstrate that the surface layer structure, inclination-angle of the spacer yarn and the volume fraction and type of microballoon have a significant influence on the low-impact performance of SF-WKSF. In addition, a finite element analysis finished with ANSYS/LS-DYNA and LS-PrePost was used to simulate the impact behaviors of SF-WKSF. The results of the finite element analysis are in agreement with the experimental results.

Analysis on Low Velocity Impact Damage and Compressive Residual Strength of Composite Laminates

2014 ◽  
Vol 566 ◽  
pp. 463-467
Author(s):  
Pu Xue ◽  
H.H. Chen ◽  
W. Guo
Keyword(s):  
Experimental Data ◽  
Residual Strength ◽  
Composite Laminates ◽  
Damage Mechanics ◽  
Impact Damage ◽  
Numerical Results ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

This paper studies the impact damage under low velocity impact for composite laminates based on a nonlinear progressive damage model. Damage evolution is described by the framework of the continuum damage mechanics. The real impact damage status of composite laminates has been used to analyze the residual compressive strength instead of assumptions on damage area after impact. The validity of the methodologies has been demonstrated by comparing the numerical results with the experimental data available in literature. The delamination area has an error of 11.3%. The errors of residual strength and compressive displacement are 8.9% and 15%, which indicate that the numerical results matched well with the experimental data.

Damage Assessment through Impact Force History Recording

2007 ◽  
Vol 347 ◽  
pp. 665-670 ◽  
Author(s):  
Nicolae Constantin ◽  
Mircea Găvan ◽  
Marin Sandu ◽  
Ştefan Sorohan ◽  
Viorel Anghel
Keyword(s):  
Composite Materials ◽  
Damage Assessment ◽  
Impact Force ◽  
Research Work ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Direct Information ◽  
Velocity Impact ◽  
Damage Level ◽  
The Impact

Low velocity impact is a frequent and inevitable in-service event, with higher occurrence in transportation structures. The damages following such an event are more diverse, extended and with more severe consequences in the case of composite materials and structures. The research work presented here concerns fibre reinforced polymeric composites in the forms of plates and pipes. It is continuing an effort meant to allow customers exploiting such structures to have a short cut in monitoring the integrity of this kind of structures. To this end, it is proposed a careful following of the impact force history recording, which can offer valuable and more direct information about the damage level produced under this insidious loading.

Failure Analysis of CCF300/5428 Laminates under Low Velocity Impact Based on Properties of Advanced Composite Material

2013 ◽  
Vol 387 ◽  
pp. 185-188
Author(s):  
Jian Yu Zhang ◽  
Ming Li ◽  
Li Bin Zhao ◽  
Bin Jun Fei
Keyword(s):  
Failure Analysis ◽  
Composite Laminates ◽  
Damage Model ◽  
Failure Criteria ◽  
Low Velocity Impact ◽  
Material System ◽  
Low Velocity ◽  
3D Fem ◽  
Velocity Impact ◽  
The Impact

A progressive damage model (PDM) composed by 3D FEM, Hashin and Ye failure criteria and Changs degradation rules was established to deeply understand the failure of a new material system CCF300/5428 under low velocity impact. User defined subroutines were developed and embedded into the general FEA software package to carry out the failure analysis. Numerical simulations provide more information about the failure of composite laminates under low velocity impact, including initial damage status, damage propagation and final failure status. The history of the impact point displacement and various damage patterns were detailed studied.

scholarly journals Palliatives for Low Velocity Impact Damage in Composite Laminates

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Mubarak Ali ◽  
S. C. Joshi ◽  
Mohamed Thariq Hameed Sultan
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Laminated Composites ◽  
Low Velocity Impact ◽  
Normal Operation ◽  
Fibre Reinforcement ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Initiation ◽  
The Impact

Fibre reinforced polymer laminated composites are susceptible to impact damage during manufacture, normal operation, maintenance, and/or other stages of their life cycle. Initiation and growth of such damage lead to dramatic loss in the structural integrity and strength of laminates. This damage is generally difficult to detect and repair. This makes it important to find a preventive solution. There has been abundance of research dealing with the impact damage evolution of composite laminates and methods to mitigate and alleviate the damage initiation and growth. This article presents a comprehensive review of different strategies dealing with development of new composite materials investigated by several research groups that can be used to mitigate the low velocity impact damage in laminated composites. Hybrid composites, composites with tough thermoplastic resins, modified matrices, surface modification of fibres, translaminar reinforcements, and interlaminar modifications such as interleaving, short fibre reinforcement, and particle based interlayer are discussed in this article. A critical evaluation of various techniques capable of enhancing impact performance of laminated composites and future directions in this research field are presented in this article.

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