scholarly journals Impact Response of Composite Sandwich Cylindrical Shells

2021 ◽  
Vol 11 (22) ◽  
pp. 10958
Author(s):  
Paulo N. B. Reis ◽  
Carlos A. C. P. Coelho ◽  
Fábio V. P. Navalho
Keyword(s):  
Cylindrical Shell ◽  
Cylindrical Shells ◽  
Carbon Composite ◽  
Industrial Applications ◽  
Static Properties ◽  
Static Tests ◽  
Impact Performance ◽  
Composite Sandwich ◽  
Impact Tests ◽  
The Impact

Nowadays, due to the complexity and design of many advanced structures, cylindrical shells are starting to have numerous applications. Therefore, the main goal of this work is to study the effect of thickness and the benefits of a carbon composite sandwich cylindrical shell incorporating a cork core, compared to a conventional carbon composite cylindrical shell, in terms of the static and impact performances. For this purpose, static and impact tests were carried out with the samples freely supported on curved edges, while straight edges were bi-supported. A significant effect of the thickness on static properties and impact performance was observed. Compared to thinner shells, the failure load on the static tests increased by 237.9% and stiffness by 217.2% for thicker shells, while the restored energy obtained from the impact tests abruptly increased due to the collapse that occurred for the thinner ones. Regarding the sandwich shells, the incorporation of a cork core proved to be beneficial because it promoted an increase in the restored energy of around 44.8% relative to the conventional composite shell. Finally, when a carbon skin is replaced by a Kevlar one (hybridization effect), an improvement in the restored energy of about 20.8% was found. Therefore, it is possible to conclude that numerous industrial applications can benefit from cylindrical sandwiches incorporating cork, and their hybridization with Kevlar fibres should be especially considered when they are subject to impact loads. This optimized lay-up is suggested because Kevlar fibres fail through a series of small fibril failures, while carbon fibres exhibit a brittle collapse.

Experimental investigation of the quasi-static and impact tests on the energy absorption characteristics of coupler rubber buffers used in railway vehicles

2018 ◽  
Vol 233 (9) ◽  
pp. 937-950 ◽  
Author(s):  
Shuguang Yao ◽  
Zhixiang Li ◽  
Wen Ma ◽  
Ping Xu ◽  
Quanwei Che
Keyword(s):  
Energy Absorption ◽  
Impact Velocity ◽  
High Speed ◽  
Compression Tests ◽  
Static Compression ◽  
Static Tests ◽  
Impact Tests ◽  
High Speed Trains ◽  
The Impact ◽  
Absorption Characteristics

Coupler rubber buffers are widely used in high-speed trains, to dissipate the impact energy between vehicles. The rubber buffer consists of two groups of rubbers, which are pre-compressed and then installed into the frame body. This paper specifically focuses on the energy absorption characteristics of the rubber buffers. Firstly, quasi-static compression tests were carried out for one and three pairs of rubber sheets, and the relationship between the energy absorption responses, i.e. Eabn  =  n ×  Eab1, Edissn =  n ×  Ediss1, and Ean =  Ea1, was obtained. Next, a series of quasi-static tests were performed for one pair of rubber sheet to investigate the energy absorption performance with different compression ratios of the rubber buffers. Then, impact tests with five impact velocities were conducted, and the coupler knuckle was destroyed when the impact velocity was 10.807 km/h. The results of the impact tests showed that with the increase of the impact velocity, the Eab, Ediss, and Ea of the rear buffer increased significantly, but the three responses of the front buffer did not increase much. Finally, the results of the impact tests and quasi-static tests were contrastively analyzed, which showed that with the increase of the stroke, the values of Eab, Ediss, and Ea increased. However, the increasing rates of the impact tests were higher than that of the quasi-static tests. The maximum value of Ea was 68.76% in the impact tests, which was relatively a high value for the vehicle coupler buffer. The energy capacity of the rear buffer for dynamic loading was determined as 22.98 kJ.

Study of the Impact Performance of Solder Joints by High-Velocity Impact Tests

2010 ◽  
Vol 39 (12) ◽  
pp. 2536-2543 ◽  
Author(s):  
Ning Zhang ◽  
Yaowu Shi ◽  
Fu Guo ◽  
Fuqian Yang
Keyword(s):  
High Velocity ◽  
Solder Joints ◽  
High Velocity Impact ◽  
Velocity Impact ◽  
Impact Performance ◽  
Impact Tests ◽  
The Impact

Validation of a computer simulation of the impact performance of a wire rope safety fence

2007 ◽  
Vol 221 (12) ◽  
pp. 1557-1570 ◽  
Author(s):  
M B Bateman ◽  
I C Howard ◽  
A R Johnson ◽  
J M Walton
Keyword(s):  
Computer Simulation ◽  
Wire Rope ◽  
Design Tool ◽  
Research Association ◽  
Test Results ◽  
Impact Performance ◽  
Impact Tests ◽  
Motor Industry ◽  
The Uk ◽  
The Impact

A computer simulation has been developed at The University of Sheffield that predicts the impact performance of roadway wire rope safety fences. Effective use of this simulation for design, or other purposes, requires it to be validated by showing that the predicted vehicle motion and fence response closely represent that of the real system. Two distinct validation studies are described in the current paper. The first compares the major results of eight impact tests undertaken at the UK Motor Industry Research Association and a further four impact tests undertaken at the Swedish Road and Transport Research Institute with the simulation predictions. The close prediction of the test results validates the use of the simulation as a design tool for a range of fence designs and impact conditions. The second validation study compares, in detail, the test results and simulation prediction for a single test. This suggests that, if required, results may be improved further by considering suspension effects in the vehicle model, and by a better understanding of frictional effects at the rope-post and the rope-vehicle contacts.

scholarly journals On the Multi-Functional Behavior of Graphene-Based Nano-Reinforced Polymers

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5828
Author(s):  
Konstantina Zafeiropoulou ◽  
Christina Kostagiannakopoulou ◽  
Anna Geitona ◽  
Xenia Tsilimigkra ◽  
George Sotiriadis ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Impact Resistance ◽  
Reinforced Polymers ◽  
Impact Performance ◽  
Impact Tests ◽  
Weight Content ◽  
Roll Mill ◽  
Doped Polymers ◽  
The Impact

The objective of the present study is the assessment of the impact performance and the concluded thermal conductivity of epoxy resin reinforced by layered Graphene Nano-Platelets (GNPs). The two types of used GNPs have different average thicknesses, <4 nm for Type 1 and 9–12 nm for Type 2. Graphene-based polymers containing different GNP loading contents (0.5, 1, 5, 10, 15 wt.%) were developed by using the three-roll mill technique. Thermo-mechanical (Tg), impact tests and thermal conductivity measurements were performed to evaluate the effect of GNPs content and type on the final properties of nano-reinforced polymers. According to the results, thinner GNPs were proven to be more promising in all studied properties when compared to thicker GNPs of the same weight content. More specifically, the glass transition temperature of nano-reinforced polymers remained almost unaffected by the GNPs inclusion. Regarding the impact tests, it was found that the impact resistance of the doped materials increased up to 50% when 0.5 wt.% Type 1 GNPs were incorporated within the polymer. Finally, the thermal conductivity of doped polymers with 15 wt.% GNPs showed a 130% enhancement over the reference material.

DYNAMIC IMPACT RESISTANCE OF COMPOSITE SANDWICH PANELS WITH 3-D PRINTED POLYMER SYNTACTIC FOAM CORES

2021 ◽  
Author(s):  
H. R. TEWANI ◽  
DILEEP BONTHU ◽  
H. S. BHARATH ◽  
MRITYUNJAY DODDAMANI ◽  
P. PRABHAKAR
Keyword(s):  
Impact Resistance ◽  
Syntactic Foam ◽  
Sandwich Panels ◽  
Syntactic Foams ◽  
Dynamic Impact ◽  
Impact Performance ◽  
Composite Sandwich Panels ◽  
Composite Sandwich ◽  
Back Face ◽  
The Impact

Polymer-based syntactic foams find use in the marine industry as primary structural materials due to their inherent lightweight nature and enhanced mechanical properties relative to pure HDPE. 3-D printing these materials circumvents the use of joining assemblies, enabling the production of complex shapes as standalone structures. Although the quasi-static response of these 3D printed foams has been well studied independently in recent years, their dynamic impact resistance and tolerance as potential core material for sandwich panels have not been the focus. Moreover, 3D printing is known to impart directionality in the printed syntactic foams, which may introduce failure mechanisms typically not observed in molded foams. It is therefore important to investigate the mechanics of 3-D printed syntactic foam core composite sandwich structures under impact loading and characterize their failure mechanisms for establishing dynamic impact resistance. To this end, 3-D printed syntactic foams have been developed using rasters of High-Density Polyethylene (HDPE) and Glass MicroBalloon (GMB) fillers by adopting the Fused Raster Fabrication (FFF) technique. The current study is performed to assess the impact performance of these composite foam cores based on the volume fraction of fillers and print orientation. The weight percentage of GMB fillers in printed specimens ranges from 0% to 60% in increments of 20%. This study presents the impact response of these composite sandwich panels at different energy levels, in compliance with ASTM D7136/D7136M - 20. Observations suggest that an increase in GMB % in HDPE matrix improves the impact performance in terms of the peak load of the material, but the failure behavior becomes brittle to an extent. Observing the failed specimens under a Micro-CT scanner captures the failure morphologies and helps characterize failure processes during impact. It is noticed that core materials with higher GMB content are prone to individual raster breakage and delamination at the back face, in addition to debonding between individual rasters. Specimens printed along the longer dimension (y-direction) impart more warping in the final sandwich structures than that of specimens printed along the shorter dimension (x-direction). Therefore, they are more susceptible to delamination at the back face. Addition of GMB fillers mitigate the tendency of the sandwich panels to warp.

INVESTIGATION ON ENERGY ABSORPTION OF ALUMINIUM FOAM-CFRP SANDWICH PANEL SUBJECTED TO IMPACT LOADING

2015 ◽  
Vol 75 (8) ◽  
Author(s):  
Mohd Fadzli Ismail ◽  
Aidah Jumahat ◽  
Bulan Abdullah ◽  
Ummu Raihanah Hashim ◽  
Shafika Elia Ahmad Aseri
Keyword(s):  
Energy Absorption ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
High Strength ◽  
Aluminium Foam ◽  
Impact Properties ◽  
Composite Sandwich ◽  
Impact Tests ◽  
Cfrp Composite ◽  
The Impact

Sandwich panels are widely used in the fabrication of high strength low-weight structure that can withstand impact and blast loading especially for aerospace and automotive structures. Currently, aluminium foam is one of the lightweight materials used as a core in sandwich panels. The combination properties of core and face-sheet material are important to produce high strength and lightweight sandwich panel. This research is aimed to develop a carbon fibre reinforced polymer (CFRP) composite sandwich panel with aluminium foam as a core and study the impact properties of the structure. The preparations of the sandwich panel involved closed-cell aluminum foam as a core material and CFRP composite as the face-sheets. The impact tests were conducted using an Instron Dynatup 9250HV impact tester machine according to ASTM standard D3763 under constant impact velocity of 6.7m/s. The results of the impact tests showed that CFRP composite sandwich panel has better impact properties when compared to the other systems where it has higher specific energy absorption and longer impact time.  

Numerical Modelling of Impact Behavior of Composite Sandwich Panel With Honeycomb Core

2019 ◽  
Author(s):  
Shah Alam ◽  
Aakash Bungatavula
Keyword(s):  
Sandwich Panel ◽  
Sheet Thickness ◽  
Face Sheet ◽  
Honeycomb Core ◽  
Impact Performance ◽  
Composite Sandwich ◽  
The Core ◽  
The Face ◽  
Core Height ◽  
The Impact

Abstract The goal of this paper is to find the best impact response of the composite sandwich panels with honeycomb core. The focus of the study is to find the effects of changing the face sheet thickness and the core height of the sandwich panel subjected to variable velocities on impact performance. Initially, honeycomb core sandwich panel with 1mm thick face sheet is modelled in Abaqus/explicit to calculate the energy absorption, residual velocity, and deformation at four different velocities. Then, the process is repeated by changing the face sheets thickness to 2mm and 3mm to see the effects of changing the thickness on the impact performance of a composite sandwich panel. The honeycomb core height is also changed to see its effect on the performance. In all models, Al 7039 is used in the core and T1000G is used in the face sheets.

Research on the Dropping Impact Performance of Transporting Packages of Crown Pears

2012 ◽  
Vol 200 ◽  
pp. 160-163
Author(s):  
Chang Wei Cui
Keyword(s):  
Peak Acceleration ◽  
Repeated Impact ◽  
Impact Performance ◽  
Impact Tests ◽  
Three Stages ◽  
The Impact

In this paper, the repeated dropping impact tests of transporting packages of crown pear were implemented to study the cushion performance of the corrugated papers, which used as the buffer liner, including three-storey , five-storey and seven-storey corrugated boards. The results show that there are three stages in the process of peak acceleration varied with the impact cycles, and the repeated impact strengths of transporting packages of the fruit obviously increase with the increasing wall number of cushion boards.

Influence of microstructural voids on the mechanical and impact properties in commingled E-glass/polypropylene thermoplastic composites

2002 ◽  
Vol 216 (2) ◽  
pp. 85-100 ◽  
Author(s):  
C Santulli ◽  
R Brooks ◽  
C D Rudd ◽  
A C Long
Keyword(s):  
Shear Strength ◽  
Composite Structures ◽  
Three Dimensional ◽  
Interlaminar Shear Strength ◽  
Void Content ◽  
Impact Properties ◽  
Impact Performance ◽  
Impact Tests ◽  
Interlaminar Shear ◽  
The Impact

In recent years, the compression moulding of E-glass/polypropylene commingled composites has been thoroughly investigated. In particular, in the University of Nottingham, a number of studies have been carried out, trying to correlate moulding parameters with mechanical properties and microstructural void content. However, some aspects of commingled composites have received less coverage so far and are therefore dealt with in this paper. These concern the effect of the processing conditions of these materials on interlaminar shear strength and impact properties and the influence of the synergy between processing, microstructure and properties on the impact performance of commingled composite structures. With this aim, flat plaques of E-glass/polypropylene commingled composites with a different fibre architecture (two-and three-dimensional) were non-isothermally compression moulded under various moulding conditions and then tested. The test programme included falling weight impact tests with a staircase procedure, Charpy impact tests and interlaminar shear strength (ILSS) tests. To evaluate the consolidation of the laminates, void content measurement using optical microscopy was related to ILSS and impact test results. In particular, the specific issues arising in moulding laminates with added three-dimensional fibres were studied. These include correct placement of the tow, sufficient preheating of thick laminates and nesting of the layers during moulding. The results of these tests are discussed in the light of the moulding conditions and quality, and conclusions are drawn regarding optimum moulding conditions for impact performance. Finally, indications on the reliability and possible improvement of the moulding procedure to yield a sufficient moulding quality, even with large thickness, are also provided. The knowledge acquired on material consolidation properties is applied in the manufacture of an automotive side intrusion beam: problems due to the scale effect are also discussed.

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