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.

A Hierarchical Impact Force Reconstruction Method for Aerospace Composites

2019 ◽  
Vol 812 ◽  
pp. 17-24
Author(s):  
Mario Emanuele de Simone ◽  
Francesco Ciampa ◽  
Michele Meo
Keyword(s):  
Impact Force ◽  
Research Work ◽  
Time History ◽  
Low Velocity Impact ◽  
Reconstruction Method ◽  
Low Velocity ◽  
Force Reconstruction ◽  
Structural Responses ◽  
High Level ◽  
The Impact

This research work presents a hierarchical method able to reconstruct the time history of the impact force on a composite wing stringer-skin panel by using the structural responses measured by a set of surface bonded ultrasonic transducers. Time reversal method was used to identify the impact location by the knowledge of structural responses recorded from a set of excitation points arbitrarily chosen on the plane of the structure. Radial basis function interpolation approach was then used to calculate the transfer function at the impact point and reconstruct the impact force history. Experimental results showed the high level of accuracy of the proposed impact force reconstruction method for a number of low-velocity impact sources and energies.

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.

scholarly journals Effect of Mortar Strength on the Behaviour of Ferrocement Panel Under Low Velocity Impact

2019 ◽  
Vol 8 (12) ◽  
pp. 5245-5249
Keyword(s):  
Construction Material ◽  
Equivalent Stress ◽  
Research Work ◽  
Impact Resistance ◽  
Low Velocity Impact ◽  
Construction Technology ◽  
Low Velocity ◽  
Velocity Impact ◽  
Mortar Strength ◽  
The Impact

The concept of industrialization of the construction technology has emerged as well accepted and preferred option in the field of building construction now days in order to reduce in – situ construction up to maximum extent. Ferrocement is the one of the relatively new cementitious composite considered as a construction material. The main aim of this study is to investigate the behavior of Ferrocement panel under low velocity impact. Size of panel is 250 x 250 mm and thickness is varying from 20mm to 40mm. Corrugated fibers were added in panels. Volume of corrugated fibers was considered as 1.5% of total volume of panel. Weld mesh and woven mesh were used in ferrocement panels. Numbers of layers of mesh were 2 and 3. Height of drop is 1m. M30 and M40 Grade of mortar were used. Equivalent stress, Normal stress and Deformation were the main parameters for this research work. From the results it can be concluded that weld mesh with corrugated fibers is good at the impact resistance.

The Low-Velocity Impact Response of Sandwich Panels

2010 ◽  
Vol 168-170 ◽  
pp. 1149-1152
Author(s):  
Xiao Xiong Zha ◽  
Hong Xin Wang
Keyword(s):  
Impact Force ◽  
Energy Levels ◽  
Impact Resistance ◽  
Sandwich Panels ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Weight Impact ◽  
The Impact

The low velocity impact response of sandwich panels at different energy levels has been investigated by conducting drop-weight impact tests using an instrumented falling-weight impact tower. Impact parameters like maximum impact force and the extent of the damage were evaluated and compared for different types of sandwich panels. Finite elements simulations have been undertaken using the LS-DYNA software; the results of FE simulations have a good agreement with the experiments. It shows that, the impact force increased with thickness of face-sheets and foam core, the extent of the damage increased with the impact energy, sandwich panels with steel face sheet has a good impact resistance in comparison with sandwich panel with aluminum face sheets.

Nondestructive Methods for the Damage Assessment of Cylindrically Curved Composite Laminates Subjected to Low-Velocity Impact

2002 ◽  
Author(s):  
Oh-Yang Kwon ◽  
Jung-Kyu Jun ◽  
Yuris A. Dzenis
Keyword(s):  
Composite Laminates ◽  
Damage Assessment ◽  
Impact Damage ◽  
Acoustic Microscopy ◽  
Low Velocity Impact ◽  
Layer By Layer ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact ◽  
Maximum Contact

Curved composite laminates appeared to be more vulnerable than flat ones to rapid transverse loading. Damage induced by low-velocity impact on the cylindrically curved composite laminates has been experimentally investigated. Graphite/epoxy shells with the radius of curvatures of 150 mm showed quite different impact response and damage behavior from that of flat laminate. Under the same impact energy level, the maximum contact force varied with the radius of curvatures, which is directly related to the impact damage. Delamination was distributed rather evenly at each interface along the thickness direction of curved laminates on the contrary to the case of flat laminates, where delamination is typically concentrated at the interfaces away from the impact point. Due to the presence of curvature, the acoustic microscopy could not be directly applied to the layer-by-layer assessment of delamination damage. As an alternative, the penetrant-enhanced X-radiography (PEXR) was introduced and the results from PEXR were compared with those from destructive examination of the cross-section by scanning electron microscopy.

Particular Aspects Concerning Low Velocity Impact on Composite Tubes

2009 ◽  
Vol 417-418 ◽  
pp. 425-428
Author(s):  
Nicolae Constantin ◽  
Ştefan Sorohan ◽  
Mircea Găvan ◽  
Viorel Anghel
Keyword(s):  
Main Parameter ◽  
Impact Force ◽  
Epoxy Composite ◽  
Low Velocity Impact ◽  
Impact Event ◽  
Low Velocity ◽  
Velocity Impact ◽  
Weight Impact ◽  
Composite Pipes ◽  
The Impact

The study had in view various aspects which can arise during the low velocity impact tests made on composite pipes/tubes. It implied numerical simulations, made by ANSYS and LS-DYNA codes, on glass fiber/epoxy composite pipes. The geometry and material characteristics were taken from real pipes, which have been experimentally tested in parallel, using a drop weight impact tower. The main parameter in view was the impact force history, which gives most information upon the impact event and, accordingly, is used by most of researchers for characterizing the damages produced on the impacted body and for assessing the impact installation.

Finite Element and Experimental Study of the Fiber-Reinforced Composite Laminates under Low-Velocity Impact

2013 ◽  
Vol 535-536 ◽  
pp. 505-508
Author(s):  
Han Yang Liu ◽  
Xin Ming Qiu ◽  
Deng Yu Zhang ◽  
Yu Huai He ◽  
Jin Juan Fan
Keyword(s):  
Composite Laminates ◽  
Failure Modes ◽  
Failure Criteria ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Level ◽  
Nondestructive Examination ◽  
The Matrix ◽  
The Impact

Experimental and numerical studies of the 2D woven composite laminates under low-velocity impact with different energy are discussed in this paper. The traditional Hashin failure criteria are improved to cover the failure modes of fiber rupture and delamination. It is found that the damage level depend on the impact energy. The matrix deformation is the main reason of delamination. The simulating results are in good agreement with the experimental phenomenon observed by nondestructive examination (ultrasonic C scanning) and cross-section examination

scholarly journals Low-Velocity Impact Induced Damage Evaluation and Its Influence on the Residual Flexural Behavior of Glass/Epoxy Laminates Hybridized with Glass Fillers

2020 ◽  
Vol 4 (3) ◽  
pp. 99 ◽  
Author(s):  
Saravanakumar Kannivel ◽  
Harini Subramanian ◽  
Vellayaraj Arumugam ◽  
Hom N. Dhakal
Keyword(s):  
Impact Damage ◽  
Research Work ◽  
Substantial Improvement ◽  
Flexural Behavior ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Pull Out ◽  
Glass Fillers ◽  
The Impact

This research work investigates the low-velocity impact induced damage behavior and its influence on the residual flexural response of glass/epoxy composites improved with milled glass fillers. The low-velocity impact damage employing varying impact velocities (3 m/s, 3.5 m/s, and 4 m/s) was induced on baseline and filler loaded samples with different fiber orientations. The residual performance and their damage modes were characterized using post impact flexural (FAI) test and acoustic emission (AE) monitoring. In all fiber orientations, the filler modified glass/epoxy samples showed improved impact strength and stiffness properties. A substantial improvement in impact damage tolerance, especially for samples impacted at 3.5 m/s and 4 m/s was observed. The presence of filler at the interlaminar zone contributed to improved energy dissipation through filler debonding and pull-out. This further contributed in arresting the crack growth, showing reduced damaged area. The inclusion of milled fibers on glass/epoxy laminates enhanced the impact toughness and residual flexural behavior.

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.

Influence of the Metallic Cold Spray Deposition on the Low-Velocity Impact Behaviour of Composite Laminates

2019 ◽  
Vol 813 ◽  
pp. 376-380
Author(s):  
Ilaria Papa ◽  
Pietro Russo ◽  
Antonello Astarita ◽  
Antonio Viscusi ◽  
Alessia Serena Perna ◽  
...  
Keyword(s):  
Composite Materials ◽  
Cold Spray ◽  
Composite Laminates ◽  
Spray Deposition ◽  
Low Velocity Impact ◽  
Flame Resistance ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Behaviour ◽  
The Impact

Recently, the growing attraction to the development of new eco-sustainable composite materials is driving the research interest toward the replacement of synthetic reinforcing fibres with natural ones and exploiting the inherent recyclability of thermoplastic resins even for uses in which thermosetting matrices are well consolidated (e.g. naval and aeronautical fields). Among the natural fibres, a growing interest of the research is addressed to basalt fibres. Focusing the attention on thermoplastic composites, many experimental findings already available in literature highlight the outstanding mechanical properties of composite materials including basalt fibres and their potentiality concerning glass ones. On the other hand, some issues are related to the surface properties of the bio-laminates: in particular, the wear ones, the flame resistance and the aesthetic appearance have to be improved to extend the application fields of these materials. Aiming to these goals, this paper deals with the study of the deposition ofaluminium coating through cold spray process on polypropylene/basalt fabric composite laminates. The specimens were obtained by film stacking, and compression moulding technology and their performances were studied in terms of low-velocity impact behaviour, considering the influence of the surface modification with the aluminium coating. The results obtained from the reference laminates and the coated ones are compared in terms of impact parameters: the aluminium deposition seems to affect the damage mechanism propagation even if the impact response seems to be similar in both conditions.

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