Qualifying carbon nanotube reinforced polyurethane foam as helmet inner liner through in-situ, static and low velocity impact testing

2021 ◽  
Vol 274 ◽  
pp. 115496
Author(s):  
Jasdeep Bhinder ◽  
Sanjeev Kumar Verma ◽  
Prabhat K. Agnihotri
Keyword(s):  
Carbon Nanotube ◽  
Polyurethane Foam ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact

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.

Grid-Characteristic Numerical Method for Low-Velocity Impact Testing of Fiber-Metal Laminates

2018 ◽  
Vol 39 (7) ◽  
pp. 874-883 ◽  
Author(s):  
K. A. Beklemysheva ◽  
A. V. Vasyukov ◽  
A. O. Kazakov ◽  
I. B. Petrov
Keyword(s):  
Numerical Method ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Fiber Metal Laminates ◽  
Velocity Impact ◽  
Fiber Metal

Exceptional Superhydrophobicity and Low Velocity Impact Icephobicity of Acetone-Functionalized Carbon Nanotube Films

Langmuir ◽  
2011 ◽  
Vol 27 (16) ◽  
pp. 9936-9943 ◽  
Author(s):  
Liqiu Zheng ◽  
Zhongrui Li ◽  
Shawn Bourdo ◽  
Khedir R. Khedir ◽  
Madhu P. Asar ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Functionalized Carbon Nanotube ◽  
Nanotube Films

scholarly journals Ultrasonic Analysis of Damage in CFRP Resulting from Static Indentation and Low Velocity Impact

1993 ◽  
Vol 2 (3) ◽  
pp. 096369359300200
Author(s):  
H. Kaczmarek
Keyword(s):  
Impact Testing ◽  
Low Velocity Impact ◽  
Ultrasonic Tomography ◽  
Transverse Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Testing Procedures ◽  
Damage Initiation ◽  
Static Indentation ◽  
The Impact

In order to reduce hidden damage caused in CFRP by low velocity transverse impact, testing procedures must be established by understanding the impact phenomena and the roles of various parameters on damage initiation and growth. Hence, composite plates were stressed and an original method, “ultrasonic tomography,” was applied to detect delaminations on the interfaces. The results show the similarity of the damage growth resulting from static indentation and low velocity impact.

Impact Damage and Strength Reduction Behavior of Honeycomb Sandwich Structure Subjected to Low Velocity Impact

2006 ◽  
Vol 306-308 ◽  
pp. 279-284
Author(s):  
Ki Weon Kang ◽  
Jung Kyu Kim ◽  
Heung Seob Kim
Keyword(s):  
Sandwich Structure ◽  
Impact Damage ◽  
Testing Machine ◽  
Strength Reduction ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Reduction Behavior ◽  
Velocity Impact ◽  
The Impact

The goals of the paper are to identify the impact damage and strength reduction behavior of sandwich structure, composed of carbon/epoxy laminates skin and Nomex core with two kinds of thickness (10 and 20mm). For these, low velocity impact tests were conducted using the instrumented impact-testing machine and damages are inspected by SAM. And then, subsequent static tests are conducted under flexural loading to identify the strength reduction behavior of the impacted sandwich structures. The impact damages are mainly delamination in carbon/epoxy skin and their behavior is mostly independent of core thickness. Also, their energy absorbing behavior is identified through calculating the energy absorbed by impact damage. Finally, the strength reduction behavior is evaluated through Caprino’s model, which was proposed on the unidirectional laminates.

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