An analytical model to predict the impact of a bullet on ultra-high molecular weight polyethylene composite laminates

2021 ◽  
pp. 115064
Author(s):  
Li Jintao ◽  
Liu Moubin
Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2489
Author(s):  
Michał Bembenek

When considering the operation of roller presses for the consolidation of fine-grained materials, the main problems are disturbances in the proper flow of the material and its bridging in gravity feeders. This is especially true for small and medium capacity presses, where the hoppers for dosing the material are narrow. This article presents innovative laboratory tests of the impact of using a polymer plate lining in the gravity feeder of a roller press. Polymer materials Polyacetal C (POM C) and Ultra-High-Molecular-Weight Polyethylene (UHMW-PE) were used for the tests. The influence of the use of plates on the material flow and quality of briquettes was investigated in comparison with the case where such plates were not used. The research showed an improvement in the flow of fine-grained materials in the feeder and an increase of the briquette strength indexes, as compared to those cases when polymer linings were not used in the feeder.


2019 ◽  
Vol 14 ◽  
pp. 155892501983252
Author(s):  
Cuiyu Li ◽  
Rui Zhang ◽  
Jingyan Jia ◽  
Gaopan Wang ◽  
Yameng Shi

This study investigated the impact and post-impact behavior of different layer weft plain knitted composite materials based on modified ultra-high-molecular-weight polyethylene/epoxy composites. The modified ultra-high-molecular-weight polyethylene weft plain knitted composites with 8, 12, 16 layers were prepared by vacuum-assisted resin transfer molding process and then subjected to impact and post-impact compression test. The impact properties were analyzed using the contact force–deflection and energy–time curves, and the post-impact compression was analyzed using the compression strength–strain curves. It can be obtained that the maximum contact force, absorbed energy, and residual compression strength after impact of the 16-layer specimen are 81.40%, 74.18%, and 73.25% more than those in the 8-layer specimen. respectively. According to the ultrasonic C-scan tests for the impact samples, the 16-layer specimen had the least damage area after the impact test, and the 8-layer composites damage area was 117.45% more than the 16-layer specimen.


2020 ◽  
Vol 90 (15-16) ◽  
pp. 1713-1729 ◽  
Author(s):  
Calvin Ralph ◽  
Lisa Baker ◽  
Edward Archer ◽  
Alistair McIlhagger

Typical soft armor systems are constructed of multiple layers of a single fabric type. This empirical research sought to begin optimization of these systems through hybridization, sequencing dissimilar armor fabrics to maximize their ballistic protective performance, by first investigating single plies with a spectrum of properties to determine their behavior and response to impact. Eight individual plain weave fabrics with varying yarns and thread counts were manufactured from para-aramid and ultra-high molecular weight polyethylene (UHMWPE) yarns and physical and ballistic characterizations were conducted. The ballistic impact tests established the specific energy absorption (SEA) of each fabric across a range of impact velocities (340–620 m·s–1) and the transverse displacement wave velocity across the rear of the fabric was found using digital image correlation. Low cover factor ( Cfab) fabrics (0.74–0.84) consistently showed faster transverse wave speed than the high Cfab fabrics (0.84–0.96) for any given yarn type. The relative SEA of the fabrics varied dependent on both the impact velocity and number of plies impacted. It was found that lower Cfab fabrics had the highest SEA, critical velocity and transverse wave velocity. UHMWPE fabrics were not considered suitable for a woven hybrid system as they had a significantly lower SEA compared to all the para-aramid fabrics. Results indicate that a hybrid system, when considered as a theoretical spaced system, would benefit from higher Cfab fabrics as rearward layers. However, transverse wave results suggest the lower response of these fabrics may inhibit lower Cfab fabrics at the front of a combined hybridized system.


2015 ◽  
Vol 103 ◽  
pp. 436-443 ◽  
Author(s):  
Long H. Nguyen ◽  
Torsten R. Lässig ◽  
Shannon Ryan ◽  
Werner Riedel ◽  
Adrian P. Mouritz ◽  
...  

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