Low Velocity Punch-Shear Response of Nanoclay and Graphite Platelet Reinforced Vinyl Ester Plates, Laminated Face Sheets and Sandwich Composites

2009 ◽  
Author(s):  
Brahmananda Pramanik ◽  
P. Raju Mantena
Keyword(s):  
Vinyl Ester ◽  
Impact Load ◽  
Cost Effective ◽  
Test System ◽  
Experimental Methodology ◽  
Low Velocity Impact ◽  
Sandwich Composites ◽  
Low Velocity ◽  
Shear Response ◽  
The Impact

Focus of our research is on developing stronger, safer and more cost-effective structures for the new generation naval ships; especially nanoparticle reinforced glass/carbon polymeric based composites and structural foams for blast/shock/impact mitigation. Punch-shear test at low velocity impact is significant for mechanical characterization. Gama et al. [1] performed QS-PST experimental methodology to define elastic energy and absorbed energies of composites as a function of penetration displacement. This paper describes the punch-shear response of nanoparticle reinforced vinyl ester plates, laminated face sheets and sandwich composites using Dynatup 8250 drop-weight impact test system according to ASTM D3763 Standard [2]. Low-velocity tests were performed on 4″ × 4″ square plate specimens with fixed circular boundary condition and impacted by a hemispherical-head plunger with added mass. The impact load, displacement, energy plots and visual inspection of the post damaged specimens depicted the failure characteristics and punch shear response of these composites.

Low Velocity and Compression-After-Impact Response of Pin-Reinforced Sandwich Composites

1999 ◽  
Author(s):  
Uday K. Vaidya ◽  
Mohan V. Kamath ◽  
Mahesh V. Hosur ◽  
Anwarul Haque ◽  
Shaik Jeelani
Keyword(s):  
Impact Testing ◽  
Low Velocity Impact ◽  
Sandwich Composites ◽  
Low Velocity ◽  
Static Compression ◽  
Velocity Impact ◽  
Transverse Stiffness ◽  
Impact Studies ◽  
Compression After Impact ◽  
The Impact

Abstract In the current work, sandwich composite structures with innovative constructions referred to as Z-pins, or truss core pins are investigated, in conjunction with traditional honeycomb and foam core sandwich constructions, such that they exhibit enhanced transverse stiffness, high damage resistance and furthermore, damage tolerance to impact. While the investigations pertaining to low velocity impact have appeared recently in Vaidya et al. 1999, the current paper deals with compression-after-impact studies conducted to evaluate the residual properties of sandwich composites “with” and “without” reinforced foam cores. The resulting sandwich composites have been investigated for their low velocity (< 5 m/sec) impact loading response using instrumented impact testing at energy levels ranging from 5 J to 50 J impact energy. The transverse stiffness of the cores and their composites has also been evaluated through static compression studies. Compression-after-impact studies were then performed on the sandwich composites with traditional and pin-reinforcement cores. Supporting vibration studies have been conducted to assess the changes in stiffness of the samples as a result of the impact damage. The focus of this paper is on the compression-after-impact (CAI) response and vibration studies with accompanying discussion pertaining to the low velocity impact.

scholarly journals Research on the Response Characteristics of Bio-Inspired Composite Sandwich Structure under Low Velocity Impact

2021 ◽  
Vol 2101 (1) ◽  
pp. 012087
Author(s):  
Peng Hao ◽  
Lin’an Li ◽  
Jianxun Du
Keyword(s):  
Sandwich Structure ◽  
Mechanical Response ◽  
Shear Fracture ◽  
Impact Load ◽  
High Energy ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Response Characteristics ◽  
Composite Sandwich ◽  
The Impact

Abstract In order to research the impact mechanical response characteristics of the bio-inspired composite sandwich structure, the hemispherical impactor is preloaded with different energy to impact bio-inspired and conventional composite sandwich structure, the stress distribution and dynamic response characteristics of composite sandwich structure under impact load are studied. The results show that the main damage of the upper panel is fiber shear fracture, while crushing fracture for the core, and the main damage of the lower panel is fiber tensile tearing under different impact load. The bio-inspired composite sandwich structure shows better impact resistance in terms of damage depth and maximum impact load under the same impact energy. From the perspective of energy consumption, the bio-inspired structure absorbed more energy than conventional structure under high energy impact.

Impact Behaviour of Woven Natural Silk Composite Face-Sheet Sandwiched Foam under Low Velocity Impact

2013 ◽  
Vol 774-776 ◽  
pp. 1242-1249 ◽  
Author(s):  
Albert U. Ude ◽  
Ahmad K. Ariffin ◽  
Che H. Azhari
Keyword(s):  
Impact Load ◽  
Energy Levels ◽  
Low Velocity Impact ◽  
Face Sheet ◽  
Low Velocity ◽  
Velocity Impact ◽  
Natural Silk ◽  
Damage Initiation ◽  
The Impact ◽  
Composite Face

This paper describes the result of an experimental investigation on the impact damage on woven natural silk/epoxy composite face-sheet and PVC foam core sandwich panel. The test panels were prepared by hand-lay-up method. The low-velocity impact response of the composites sandwich panels is studied at three energy levels of 32, 48, and 64 joule respectively. The focus is to investigate damage initiation, damage propagation, and mechanisms of failure. It was observed that absorption energy capability decreased as impact energy increased. There was deflection on each impact load configuration at some point but their margin was insignificant. Physical examination of the specimen show that damage areas increased with increase in impact load. The novelty of this research is the use of woven natural silk fabric as a reinforcement fibre.

Application of the Mesh Superposition Technique to the Study of Delaminations in Composites Thin Plates

2012 ◽  
Vol 525-526 ◽  
pp. 533-536 ◽  
Author(s):  
Andrea Sellitto ◽  
R. Borrelli ◽  
Francesco Caputo ◽  
Aniello Riccio ◽  
Francesco Scaramuzzino
Keyword(s):  
Composite Structures ◽  
Impact Load ◽  
Laminated Composite ◽  
Low Velocity Impact ◽  
Thin Plates ◽  
Fe Model ◽  
Low Velocity ◽  
Homogenization Approach ◽  
Superposition Technique ◽  
The Impact

Laminated composite structures are increasingly finding more applications in various fields thanks to their lower weight if compared with other materials of the same strength. Nevertheless, composites thin plates show a critical behavior in terms of damage propagation mechanisms when subjected to (low velocity) impact. Indeed they tend to produce delaminations which can be hardly detected by optical inspections and can affect the global load carrying capability, leading to a premature structural collapse. The aim of this paper is to assess the capabilities of the Davies-Zhang approach (introduced in 1994 and aimed to the estimation of both the delamination initiation impact load and the size of the impact induced delaminations) by using a multiscale FE model based on the mesh superposition technique. Indeed the impact area has been modeled layer-wise with an element per layer while the rest of the structure has been modeled at laminate level by layered elements by means of a homogenization approach for the determination of the equivalent laminate material properties. The impact induced delamination area has been determined by adopting stress-based criteria. The results (in terms of delamination initiation impact force and delamination size) have been compared to the ones obtained by adopting the Davies-Zhang approach.

The Sensitivity of the Foam-Core Parameters under Impact Loading

2012 ◽  
Vol 525-526 ◽  
pp. 289-292
Author(s):  
Fei Xu ◽  
Min Ge Duan
Keyword(s):  
Impact Resistance ◽  
Low Velocity Impact ◽  
Core Material ◽  
Foam Core ◽  
Sandwich Composites ◽  
Low Velocity ◽  
Fea Model ◽  
The Face ◽  
Damage Process ◽  
The Impact

This study presents the numerical investigation of the low-velocity impact for the foam-cored sandwich composites. Firstly, the proposed FEA model is validated by comparing the results between simulation and test. The user subroutine VUMAT and the crushable foam model are chosen to describe the damage of the face sheets and the characteristics of the foam material, respectively. The detailed damage process of the sheets and the foam is clearly shown. The sensitivity of seven parameters related to foam-core material are studied. It is shown that the yield strength, the fracture strain and the fracture displacement have significant effects on the impact-resistance of the foam-cored sandwich composites.

scholarly journals Low-Velocity Impact Resistance of Al/Gf/PP Laminates with Different Interface Performance

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4416
Author(s):  
Yanyan Lin ◽  
Huaguan Li ◽  
Zhongwei Zhang ◽  
Jie Tao
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Impact Load ◽  
Rear Surface ◽  
Impact Resistance ◽  
Nitrogen Plasma ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

The weak interface performance between metal and composite (IPMC) makes the composite materials susceptible to impact load. Aluminum/glass fiber/polypropylene (Al/Gf/PP) laminates were manufactured with the aluminum alloy sheets modified by nitrogen plasma surface treatment and the phosphoric acid anodizing method, respectively. FEM models of Al/Gf/PP laminates under low-velocity impact were established in ABAQUS/Explicit based on the generated data including the model I and II interlaminar fracture toughness. Low-velocity impact tests were performed to investigate the impact resistance of Al/Gf/PP laminates including load traces, failure mechanism, and energy absorption. The results showed that delamination was the main failure mode of two kinds of laminates under the impact energy of 20 J and 30 J. When the impact energy was between 40 J and 50 J, there were metal cracks on the rear surface of the plasma pretreated specimens, which possessed higher energy absorption and impact resistance, although the integrity of the laminates could not be preserved. Since the residual compressive stress was generated during the cooling process, the laminates were more susceptible to stretching rather than delamination. For impact energy (60 J) causing the through-the-thickness crack of two kinds of laminates, plasma pretreated specimens exhibited higher SEA values close to 9 Jm2/kg due to better IPMC. Combined with the FEM simulation results, the interface played a role in stress transmission and specimens with better IPMC enabled the laminates to absorb more energy.

scholarly journals Impact Response and Damage Characteristics of Carbon Fiber Reinforced Aluminum Laminates Under Low Velocity Impact Loading

2020 ◽  
Vol 9 (4) ◽  
pp. 1831-1837
Keyword(s):  
Impact Energy ◽  
Impact Load ◽  
Three Dimensional ◽  
Low Velocity Impact ◽  
Fe Model ◽  
Low Velocity ◽  
Fiber Layer ◽  
Cross Sectional ◽  
Velocity Impact ◽  
The Impact

CARALL hybrid material has been extensively used in the aircraft structure due to their competitive impact strength. Low velocity impact test is utilized to evaluate the impact and damage properties for such material. It is also employed to observe complex damage mechanisms. A numerical modelling is an alternative way for impact assessment. This paper investigates the impact and damage properties under low velocity impact using numerical modeling and experimental work. A three-dimensional (3D) finite element (FE) model was devolved and validated with two studies from the literature. This model was meshed with solid elements. It was subjected to 2.4 m/s impact velocity and to 10 J impact energy. Absorbed energy, penetration, impact load and damage morphology were obtained. The impact energy was efficiently absorbed by the material. Both aluminum alloy layers underwent plastic deformation whereas the fiber layer failed. A macroscopic cross-sectional morphology was presented using the FE model. An agreement between the numerical and the experiment results were achieved and discussed.

LOW VELOCITY IMPACT OF PLATE AND HEMISPHERIC IMPACTOR: PHYSICAL EXPERIMENT, NUMERICAL COMPUTATION, AND APPLICATION TO REAL SYSTEM

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1355-1360
Author(s):  
SUJIN PARK ◽  
MOONSAENG KIM ◽  
WOOK DOKKO
Keyword(s):  
Test System ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Mindlin Plate ◽  
Integration Scheme ◽  
Flow Rule ◽  
Plate Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

Steel plates subjected to low velocity impact were numerically analyzed, and physically tested. The impactor has hemispheric tip nose, and the square plate has four fixed edges. Mindlin plate theory and Hertz contact law were used for the formulation of the impact problem, and some numerical treatments for the reduced integration, Newmark time integration scheme, associative flow rule, and plastic hardening were appropriately applied. A simple and efficient analysis program for plate impact was generated, and the results were compared with those of physical impact experiments. A drop test system was installed, and the impact behavior was measured with sensors. The comparison showed reasonable results, and the main parameters of plate impact were also analyzed.

scholarly journals Experimental and Numerical Investigation of Striker Shape Influence on the Destruction Image in Multilayered Composite after Low Velocity Impact

2019 ◽  
Vol 10 (1) ◽  
pp. 288 ◽  
Author(s):  
Sebastian Sławski ◽  
Małgorzata Szymiczek ◽  
Jarosław Kaczmarczyk ◽  
Jarosław Domin ◽  
Sławomir Duda
Keyword(s):  
Impact Load ◽  
Low Velocity Impact ◽  
Composite Panel ◽  
Composite Panels ◽  
Low Velocity ◽  
Bilateral Constraints ◽  
Numerical Research ◽  
Shape Influence ◽  
The Impact ◽  
Delamination Area

The paper presents results obtained by experimental and numerical research focusing on the influence of the strikers’ geometry at the images of the destruction created in hybrid composite panels after applying impact load. In the research, the authors used four strikers with different geometry. The geometries were designed to keep the same weight for each of them. The composite panels used in the experiment were reinforced with aramid and carbon fabrics. An epoxy resin was used as a matrix. The experiments were carried with an impact kinetic energy of 23.5 J. The performed microscopy tests allowed for determination of destruction mechanisms of the panels depending on the geometry of the striker. The numerical calculations were performed using the finite element method. Each reinforcement layer of the composite was modeled as a different part. The bonded connection between the reinforcement layers was modeled using bilateral constraints. That approach enabled engineers to observe the delamination process during the impact. The results obtained from experimental and numerical investigations were compared. The authors present the impact of the striker geometry on damage formed in a composite panel. Formed damage was discussed. On the basis of the results from numerical research, energy absorption of the composite during impact depending on the striker geometry was discussed. It was noted that the size of the delamination area depends on the striker geometry. It was also noted that the diameter of the delamination area is related to the amount of damage in the reinforcing layers.

Numerical and experimental investigations on sandwich panels made with eco-friendly components under low-velocity impact

2021 ◽  
pp. 109963622110204
Author(s):  
Pablo Oliveira ◽  
Sebastian Kilchert ◽  
Michael May ◽  
Tulio Panzera ◽  
Fabrizio Scarpa ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Lower Energy ◽  
Shear Failure ◽  
Epoxy Polymer ◽  
Impact Load ◽  
Low Velocity Impact ◽  
Experimental Investigations ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

A low-velocity impact characterisation of a sustainable sandwich panel based on upcycled bottle caps as circular honeycomb is conducted. The recycled core aims to develop an alternative route of reusing waste bottle caps disposed in landfills. Ecological alternatives to skin (recycled PET foil) and adhesive (bio-polyurethane) are also compared with classic components (aluminium skin and epoxy polymer). A low-cost reinforcement (cement particles) is also proposed to enhance the mechanical strength of the panel. The samples are tested at several levels of impact energy, according to the type of skin, to observe their effect on mechanical behaviour. Metal skins achieve higher impact loads and energy absorption compared to PET foil. The bio-adhesive leads to a similar or enhanced maximum impact load and energy absorption compared to the epoxy adhesive. Specific properties highlight the promising performance of the bio-based adhesive with aluminium skins, reaching increments of up to 378%. The cement increases the maximum load and reduces the duration of the impact event, leading to lower energy absorption. The unreinforced epoxy polymer shows a visible adhesive peeling off from aluminium skin, while particle inclusions lead to reduced overall delamination. Biopolymer exhibits marginal adhesive debonding and stable deformation, revealing a progressive failure. In general, PET samples show core shear failure due to rupture of the skin. Crack propagation in PET samples made with biopolymer adhesive is reduced at lower energy levels. The results evidence the promising application of bottle caps in a more sustainable honeycomb core to build eco-friendly structures.

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