The impact response of graded foam sandwich structures

2013 ◽  
Vol 97 ◽  
pp. 370-377 ◽  
Author(s):  
J. Zhou ◽  
Z.W. Guan ◽  
W.J. Cantwell
Keyword(s):  
Sandwich Structures ◽  
Impact Response ◽  
The Impact

Impact resistance of Nomex honeycomb sandwich structures with thin fibre reinforced polymer facesheets

2016 ◽  
Vol 20 (5) ◽  
pp. 531-552 ◽  
Author(s):  
Longquan Liu ◽  
Han Feng ◽  
Huaqing Tang ◽  
Zhongwei Guan
Keyword(s):  
Finite Element ◽  
Impact Energy ◽  
Sandwich Structures ◽  
Impact Resistance ◽  
Impact Response ◽  
Woven Fabric ◽  
Drop Weight ◽  
Honeycomb Sandwich ◽  
Nomex Honeycomb ◽  
The Impact

In order to investigate the impact resistance of the Nomex honeycomb sandwich structures skinned with thin fibre reinforced woven fabric composites, both drop-weight experimental work and meso-mechanical finite element modelling were conducted and the corresponding output was compared. Drop-weight impact tests with different impact parameters, including impact energy, impactor mass and facesheets, were carried out on Nomex honeycomb-cored sandwich structures. It was found that the impact resistance and the penetration depth of the Nomex honeycomb sandwich structures were significantly influenced by the impact energy. However, for impact energies that cause full perforation, the impact resistance is characterized with almost the same initial stiffness and peak force. The impactor mass has little influence on the impact response and the perforation force is primarily dependent on the thickness of the facesheet, which generally varies linearly with it. In the numerical simulation, a comprehensive finite element model was developed which considers all the constituent materials of the Nomex honeycomb, i.e. aramid paper, phenolic resin, and the micro-structure of the honeycomb wall. The model was validated against the corresponding experimental results and then further applied to study the effects of various impact angles on the response of the honeycomb. It was found that both the impact resistance and the perforation depth are significantly influenced by the impact angle. The former increases with the obliquity, while the latter decreases with it. The orientation of the Nomex core has little effect on the impact response, while the angle between the impact direction and the fibre direction of the facesheets has a great influence on the impact response.

The perforation resistance of sandwich structures subjected to low velocity projectile impact loading

2012 ◽  
Vol 116 (1186) ◽  
pp. 1247-1262 ◽  
Author(s):  
J. Zhou ◽  
Z. W. Guan ◽  
W. J. Cantwell
Keyword(s):  
Sandwich Structures ◽  
Sandwich Panels ◽  
Impact Testing ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Analysis Package ◽  
The Impact

Abstract This article presents the findings of a study to investigate the impact perforation resistance of sandwich structures. The dynamic response of sandwich panels based on PVC foam cores has been evaluated by determining the energy to perforate the panels. The impact response of the sandwich structures was predicted using the finite element analysis package Abaqus/Explicit. The validated FE models were also used to investigate the effect of oblique loading and to study the impact response of sandwich panels subjected to a pressure differential equivalent to flying at an altitude of 10,000m. Low velocity impact testing has shown that the energy to perforate the sandwich panels is dependent on the properties of the core. It has been shown that increasing the density of the crosslinked PVC foams by a factor of two yielded a 600% increase in the perforation resistance of the sandwich structures. At higher densities, the crosslinked foam sandwich structures offered a superior perforation resistance to the linear PVC structures. The numerical analysis accurately predicted the perforation energies of the sandwich panels, as well as the prevailing failure mechanisms following impact. Finally, it has been shown that sandwich panels impacted at high altitude offer a similar perforation resistance to those tested at sea level.

The impact response of environmental-friendly sandwich structures

2013 ◽  
Vol 48 (25) ◽  
pp. 3083-3090 ◽  
Author(s):  
M Z Hassan ◽  
R Umer ◽  
S Balawi ◽  
W J Cantwell
Keyword(s):  
Sandwich Structures ◽  
Impact Response ◽  
Environmental Friendly ◽  
The Impact

Effect of temperature on the low-velocity impact response of environmentally friendly cork sandwich structures

2021 ◽  
pp. 109963622110354
Author(s):  
Claudia Sergi ◽  
Fabrizio Sarasini ◽  
Pietro Russo ◽  
Libera Vitiello ◽  
Enrique Barbero ◽  
...  
Keyword(s):  
Sandwich Structures ◽  
Impact Damage ◽  
Impact Resistance ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
Low Velocity ◽  
High Performing ◽  
The Impact

Impact events are common in every-day life and can severely compromise the integrity and reliability of high-performing structures such as sandwich composites that are widespread in different industrial fields. Considering their susceptibility to impact damage and the environmental issues connected with their exploitation of synthetic materials, the present work aims to propose a bio-based sandwich structure with an agglomerated cork core and a flax/basalt intraply fabric as skin reinforcement and to address its main weakness, i.e. its impact response. In-service properties are influenced by temperature, therefore the effect of high (60 °C) and low (−40°C) temperatures on the impact behavior of the proposed structures was investigated and a suitable comparison with traditional (polyvinyl chloride) (PVC) foams was provided. The results highlighted the embrittlement effect of decreasing temperature on the impact resistance of the sole cores and skins and of the overall structures with a reduction in the perforation energy that shifted, in the last case, from 50–60 J at – 40 °C up to more than 180 J at 60 °C. A maleic anhydride coupling agent in the skins hindered fundamental energy dissipation mechanisms such as matrix plasticization, determining a reduction in the perforation threshold of all composites. In particular, neat polypropylene (PP) skins displayed a perforation energy of 20 J higher than compatibilized (PPC) ones at 60 °C, while agglomerated cork sandwich structures at 60 °C were characterized by a perforation threshold higher of at least 50 J.

scholarly journals The Dynamic Impact Response of 3D-Printed Polymeric Sandwich Structures with Lattice Cores: Numerical and Experimental Investigation

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4032
Author(s):  
Shu-Yu Jhou ◽  
Ching-Chi Hsu ◽  
Jui-Chia Yeh
Keyword(s):  
Sandwich Structures ◽  
Impact Response ◽  
Absorption Characteristic ◽  
Border Effect ◽  
Shock Absorption ◽  
Explicit Finite Element ◽  
Impact Simulation ◽  
Material Stiffness ◽  
3D Printed ◽  
The Impact

This paper proposes a dynamic drop weight impact simulation to predict the impact response of 3D printed polymeric sandwich structures using an explicit finite element (FE) approach. The lattice cores of sandwich structures were based on two unit cells, a body-centred cubic (BCC) and an edge-centred cubic (ECC). The deformation and the peak acceleration, referred to as the g-max score, were calculated to quantify their shock absorption characteristic. For the FE results verification, a falling mass impact test was conducted. The FE results were in good agreement with experimental measurements. The results suggested that the strut diameter, strut length, number and orientation, and the apparent material stiffness of the lattice cores had a significant effect on their deformation behavior and shock absorption capability. In addition, the BCC lattice core with a thinner strut diameter and low structural height might lead to poor shock absorption capability caused by structure collapse and border effect, which could be improved by increasing its apparent material stiffness. This dynamic drop impact simulation process could be applied across numerous industries such as footwear, sporting goods, personal protective equipment, packaging, or biomechanical implants.

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