The NSF REU/RET Research on Energy Absorbing 3D Printed Polymer Structures

2017 ◽  
Author(s):  
Benjamin Lewis ◽  
Jonah Leary ◽  
Cynthia Dickman ◽  
Walter Petroski ◽  
Victoria Bellows ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Middle School Teachers ◽  
Undergraduate Students ◽  
Acrylonitrile Butadiene Styrene ◽  
Maximum Load ◽  
Research Experience ◽  
Unit Cells ◽  
3D Printed ◽  
Material Volume ◽  
Energy Absorbing

Energy absorption capability of structures with embedded pores depends upon the amount of voids present and their configurations/distributions. In this study, the energy absorption of acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) structures with varying pore shapes and sizes are investigated. The research was performed by two teams comprised of High School/Middle School teachers and undergraduate students as part of National Science Foundation (NSF) sponsored Research Experience for Teacher (RET)/Research Experience for Undergraduates (REU) teams. ABS samples were fabricated by Team 1 and utilized cubic unit cells with octahedral pores while Team 2 fabricated PLA samples that utilized unit cells with spherical pores. Eight sets of samples with dimensions 25mm × 25mm × 20mm were fabricated using a Makerbot Replicator 2X for ABS samples and a Lulzbot TAZ 5 for PLA samples. Each sample incorporated a 5 × 5 × 4 array of pores. All the samples were tested in compression and energy absorption per unit material volume of all the samples up to a particular maximum load was calculated from load-deflection curves. It is observed that the specific energy absorption of PLA and ABS porous structures greatly increases with increased porosity.

scholarly journals Energy Absorption Enhancement by Unit Cell Angle Grading or Sandwich Panels with Auxetic Core

2022 ◽  
Vol 58 (4) ◽  
pp. 94-101
Author(s):  
Oana Alexandra Mocian ◽  
Dan Mihai Constantinescu ◽  
Florin Baciu ◽  
Andrei Indres
Keyword(s):  
Energy Absorption ◽  
Sandwich Panels ◽  
Structural Response ◽  
Absorption Enhancement ◽  
Auxetic Materials ◽  
Unit Cells ◽  
Auxetic Structures ◽  
3D Printed ◽  
Manufacturing Techniques ◽  
Energy Absorbing

Architectured structures, particularly auxetic materials, have demonstrated encouraging applications in energy absorption as they facilitate the customization of their structural response. Specific geometries of unit cells can thus be tailored for particular needs due to recent progress in additive manufacturing techniques. This paper experimentally studies how the grading of the cell unit angle of an auxetic core in a sandwich panel affects its energy absorbing capability and structural response. 3D printed sandwich panels with uniform and graded auxetic cellular core were tested under quasistatic compression. The results show that sandwich panels with graded core exhibit much better energy absorption capabilities with higher plateau stress and densification strain. This indicates that, by appropriately controlling its geometry, auxetic structures can show further potential as core in sandwich panels for energy absorption applications.

scholarly journals Effect of the Pore Shape and Size of 3D-Printed Open-Porous ABS Materials on Sound Absorption Performance

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4474
Author(s):  
Katarina Monkova ◽  
Martin Vasina ◽  
Peter Pavol Monka ◽  
Drazan Kozak ◽  
Jan Vanca
Keyword(s):  
Sound Absorption ◽  
Negative Impact ◽  
Excitation Frequency ◽  
Volume Ratio ◽  
Acrylonitrile Butadiene Styrene ◽  
Normal Incidence ◽  
Absorption Properties ◽  
Absorption Performance ◽  
3D Printed ◽  
Material Volume

Noise has a negative impact on our environment and human health. For this reason, it is necessary to eliminate excessive noise levels. This paper is focused on the study of the sound absorption properties of materials with open-porous structures, which were made of acrylonitrile butadiene styrene (ABS) material using additive technology. Four types of structures (Cartesian, Octagonal, Rhomboid, and Starlit) were evaluated in this work, and every structure was prepared in three different volume ratios of the porosity and three different thicknesses. The sound absorption properties of the investigated ABS specimens were examined utilizing the normal incidence sound absorption and noise reduction coefficients, which were experimentally determined by the transfer function method using a two-microphone acoustic impedance tube. This work deals with various factors that influence the sound absorption performance of four different types of investigated ABS material’s structures. It was found, in this study, that the sound absorption performance of the investigated ABS specimens is strongly affected by different factors, specifically by the structure geometry, material volume ratio, excitation frequency of an acoustic wave, material’s thickness, and air space size behind the tested sound-absorbing materials.

3D Printed Cellular Structure Materials Under Impact and Compressive Loading

2020 ◽  
Author(s):  
Mahmoud K. Ardebili ◽  
Kerim Tuna Ikikardaslar ◽  
Colt Ehrnfeld ◽  
Feridun Delale
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Lattice Structure ◽  
Base Material ◽  
Acrylonitrile Butadiene Styrene ◽  
Structure Design ◽  
Impact Testing ◽  
Lateral Direction ◽  
Stacking Order ◽  
3D Printed

Abstract Advances in field of lattice structure design has become possible mainly due to the emerging capabilities of additive manufacturing (AM) or 3D printing. Lattices have the potential to reduce solid volumes, giving advantages such as weight reduction, decreased part production cost and ability to absorb energy under compressive and impact loading. These materials are anisotropic due to structural geometry and the additive nature of 3D-printed layers, which stack mainly in Normal or Lateral direction to the applied load. In this study 3D printed materials were fabricated that are nearly isotropic and are also lighter than base material. The lattice structure was formed using strut-based cell topologies that are adjoined as tetrahedrons. Two different tetrahedron density specimens were produced with Acrylonitrile Butadiene Styrene (ABS) using a Fusion Deposition Modelling (FDM) printer. The fabricated specimens were then tested for impact and compression capabilities. For comparison purposes, solid specimens with the same overall dimensions and highest infill ratio were also produced and tested. After compression and impact testing, results indicated that solid specimens’ impact energy absorption is higher with lateral stacking order relative to load, and compression resistance is higher for normal stacking order. The tetrahedron-filled specimens exhibited minimal stacking directional dependency and the higher count tetrahedron specimens provided more impact energy absorption and more resistance to compression than the lower count one. The normalization of specimens with respect to their weight indicated high density tetrahedron specimens’ impact energy absorption is nearly equal to that of solid specimens’. These results are initial steps in creating lattice structured materials that are isotropic, lighter and stronger than the base material.

Quasi-static penetration behavior of fiber-reinforced polypropylene and acrylonitrile butadiene styrene matrix composites

2021 ◽  
pp. 089270572110079
Author(s):  
Ali İmran Ayten
Keyword(s):  
Glass Fiber ◽  
Energy Absorption ◽  
Matrix Material ◽  
Acrylonitrile Butadiene Styrene ◽  
Fiber Types ◽  
Matrix Composites ◽  
Aramid Fabric ◽  
Penetration Behavior ◽  
Fiber Fabric ◽  
Butadiene Styrene

The quasi-static punch shear behaviors of thermoplastic composites with different polymer matrices and fiber types were investigated. This study was also focused on how much energy absorption capability can be increased by low fiber fractions. Maleic anhydride grafted polypropylene (MA-g-PP) and acrylonitrile butadiene styrene (MA-g-ABS) were used as the matrix material. One layer of aramid, carbon and glass fiber plain weave fabrics was used as the reinforcement material. Quasi-static punch shear test (QS-PST) was applied to the samples to understand the penetration behavior of the samples. The damaged areas were investigated and related to force-displacement curves. The results showed that the neat form of MA-g-PP exhibited 158% more energy absorption than the neat form of MA-g-ABS. In the samples containing one layer of fabric, the highest improvement was observed in the aramid fabric-reinforced MA-g-ABS matrix composites. Aramid fabric increased the energy absorption at a rate of 142.3% in comparison to the neat MA-g-ABS, while carbon fiber fabric and glass fiber fabric increased it by 40% and 63.52%, respectively. Aramid fiber fabric provided no significant improvement in the energy absorption in the MA-g-PP matrix composites, while carbon and glass fiber fabrics contributed to energy absorption at a rate of 48% and 41%, respectively.

scholarly journals Energy absorption and self-sensing performance of 3D printed CF/PEEK cellular composites

2021 ◽  
pp. 109863
Author(s):  
J Jefferson Andrew ◽  
Hasan Alhashmi ◽  
Andreas Schiffer ◽  
S Kumar ◽  
Vikram S. Deshpande
Keyword(s):  
Energy Absorption ◽  
3D Printed ◽  
Sensing Performance

scholarly journals Essential work of fracture assessment of acrylonitrile butadiene styrene (ABS) processed via fused filament fabrication additive manufacturing

2021 ◽  
Author(s):  
Pawan Verma ◽  
Jabir Ubaid ◽  
Andreas Schiffer ◽  
Atul Jain ◽  
Emilio Martínez-Pañeda ◽  
...  
Keyword(s):  
Acrylonitrile Butadiene Styrene ◽  
Essential Work ◽  
Fused Filament Fabrication ◽  
Essential Work Of Fracture ◽  
Fracture Properties ◽  
Raster Angle ◽  
3D Printed ◽  
Printing Direction ◽  
Work Of Fracture ◽  
Butadiene Styrene

AbstractExperiments and finite element (FE) calculations were performed to study the raster angle–dependent fracture behaviour of acrylonitrile butadiene styrene (ABS) thermoplastic processed via fused filament fabrication (FFF) additive manufacturing (AM). The fracture properties of 3D-printed ABS were characterized based on the concept of essential work of fracture (EWF), utilizing double-edge-notched tension (DENT) specimens considering rectilinear infill patterns with different raster angles (0°, 90° and + 45/− 45°). The measurements showed that the resistance to fracture initiation of 3D-printed ABS specimens is substantially higher for the printing direction perpendicular to the crack plane (0° raster angle) as compared to that of the samples wherein the printing direction is parallel to the crack (90° raster angle), reporting EWF values of 7.24 kJ m−2 and 3.61 kJ m−2, respectively. A relatively high EWF value was also reported for the specimens with + 45/− 45° raster angle (7.40 kJ m−2). Strain field analysis performed via digital image correlation showed that connected plastic zones existed in the ligaments of the DENT specimens prior to the onset of fracture, and this was corroborated by SEM fractography which showed that fracture proceeded by a ductile mechanism involving void growth and coalescence followed by drawing and ductile tearing of fibrils. It was further shown that the raster angle–dependent strength and fracture properties of 3D-printed ABS can be predicted with an acceptable accuracy by a relatively simple FE model considering the anisotropic elasticity and failure properties of FFF specimens. The findings of this study offer guidelines for fracture-resistant design of AM-enabled thermoplastics. Graphical abstract

scholarly journals Investigation of Energy-Absorbing Properties of a Bio-Inspired Structure

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 881
Author(s):  
Adrian Dubicki ◽  
Izabela Zglobicka ◽  
Krzysztof J. Kurzydłowski
Keyword(s):  
Absorption Capacity ◽  
Compression Tests ◽  
Element Analysis ◽  
Lightweight Structures ◽  
New Energy ◽  
Absorbing Material ◽  
Lightweight Structure ◽  
3D Printed ◽  
Deformation Force ◽  
Energy Absorbing

Numerous engineering applications require lightweight structures with excellent absorption capacity. The problem of obtaining such structures may be solved by nature and especially biological structures with such properties. The paper concerns an attempt to develop a new energy-absorbing material using a biomimetic approach. The lightweight structure investigated here is mimicking geometry of diatom shells, which are known to be optimized by nature in terms of the resistance to mechanical loading. The structures mimicking frustule of diatoms, retaining the similarity with the natural shell, were 3D printed and subjected to compression tests. As required, the bio-inspired structure deformed continuously with the increase in deformation force. Finite element analysis (FEA) was carried out to gain insight into the mechanism of damage of the samples mimicking diatoms shells. The experimental results showed a good agreement with the numerical results. The results are discussed in the context of further investigations which need to be conducted as well as possible applications in the energy absorbing structures.

scholarly journals Dynamic crushing behavior of closed-cell aluminum foams based on different space-filling unit cells

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
S. Talebi ◽  
R. Hedayati ◽  
M. Sadighi
Keyword(s):  
Surface Area ◽  
Dynamic Behavior ◽  
Energy Absorption ◽  
Peak Stress ◽  
Absorption Capacity ◽  
Unit Cell ◽  
Lattice Structures ◽  
Energy Absorption Capacity ◽  
Closed Cell ◽  
Unit Cells

AbstractClosed-cell metal foams are cellular solids that show unique properties such as high strength to weight ratio, high energy absorption capacity, and low thermal conductivity. Due to being computation and cost effective, modeling the behavior of closed-cell foams using regular unit cells has attracted a lot of attention in this regard. Recent developments in additive manufacturing techniques which have made the production of rationally designed porous structures feasible has also contributed to recent increasing interest in studying the mechanical behavior of regular lattice structures. In this study, five different topologies namely Kelvin, Weaire–Phelan, rhombicuboctahedron, octahedral, and truncated cube are considered for constructing lattice structures. The effects of foam density and impact velocity on the stress–strain curves, first peak stress, and energy absorption capacity are investigated. The results showed that unit cell topology has a very significant effect on the stiffness, first peak stress, failure mode, and energy absorption capacity. Among all the unit cell types, the Kelvin unit cell demonstrated the most similar behavior to experimental test results. The Weaire–Phelan unit cell, while showing promising results in low and medium densities, demonstrated unstable behavior at high impact velocity. The lattice structures with high fractions of vertical walls (truncated cube and rhombicuboctahedron) showed higher stiffness and first peak stress values as compared to lattice structures with high ratio of oblique walls (Weaire–Phelan and Kelvin). However, as for the energy absorption capacity, other factors were important. The lattice structures with high cell wall surface area had higher energy absorption capacities as compared to lattice structures with low surface area. The results of this study are not only beneficial in determining the proper unit cell type in numerical modeling of dynamic behavior of closed-cell foams, but they are also advantageous in studying the dynamic behavior of additively manufactured lattice structures with different topologies.

scholarly journals On the Post-Processing of 3D-Printed ABS Parts

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1559
Author(s):  
Mohammad Reza Khosravani ◽  
Jonas Schüürmann ◽  
Filippo Berto ◽  
Tamara Reinicke
Keyword(s):  
Surface Treatment ◽  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Acrylonitrile Butadiene Styrene ◽  
Experimental Tests ◽  
Fracture Load ◽  
Post Processing ◽  
Fused Deposition ◽  
Dog Bone ◽  
3D Printed

Application of Additive Manufacturing (AM) has significantly increased in the past few years. AM also known as three-dimensional (3D) printing has been currently used in fabrication of prototypes and end-use products. Considering the new applications of additively manufactured components, it is necessary to study structural details of these parts. In the current study, influence of a post-processing on the mechanical properties of 3D-printed parts has been investigated. To this aim, Acrylonitrile Butadiene Styrene (ABS) material was used to produce test coupons based on the Fused Deposition Modeling (FDM) process. More in deep, a device was designed and fabricated to fix imperfection and provide smooth surfaces on the 3D-printed ABS specimens. Later, original and treated specimens were subjected to a series of tensile loads, three-point bending tests, and water absorption tests. The experimental tests indicated fracture load in untreated dog-bone shaped specimen was 2026.1 N which was decreased to 1951.7 N after surface treatment. Moreover, the performed surface treatment was lead and decrease in tensile strength from 29.37 MPa to 26.25 MPa. Comparison of the results confirmed effects of the surface modification on the fracture toughness of the examined semi-circular bending components. Moreover, a 3D laser microscope was used for visual investigation of the specimens. The documented results are beneficial for next designs and optimization of finishing processes.

scholarly journals Routes to Research for Novice Undergraduate Neuroscientists

2006 ◽  
Vol 5 (2) ◽  
pp. 175-187 ◽  
Author(s):  
Kyle J. Frantz ◽  
Robert L. DeHaan ◽  
Melissa K. Demetrikopoulos ◽  
Laura L. Carruth
Keyword(s):  
Undergraduate Students ◽  
Attitudes Toward Science ◽  
Laboratory Research ◽  
Research Experience ◽  
Neuroscience Research ◽  
Long Term Follow Up ◽  
Apprenticeship Model ◽  
Design Experiments

Undergraduate students may be attracted to science and retained in science by engaging in laboratory research. Experience as an apprentice in a scientist's laboratory can be effective in this regard, but the pool of willing scientists is sometimes limited and sustained contact between students and faculty is sometimes minimal. We report outcomes from two different models of a summer neuroscience research program: an Apprenticeship Model (AM) in which individual students joined established research laboratories, and a Collaborative Learning Model (CLM) in which teams of students worked through a guided curriculum and then conducted independent experimentation. Assessed outcomes included attitudes toward science, attitudes toward neuroscience, confidence with neuroscience concepts, and confidence with science skills, measured via pre-, mid-, and postprogram surveys. Both models elevated attitudes toward neuroscience, confidence with neuroscience concepts, and confidence with science skills, but neither model altered attitudes toward science. Consistent with the CLM design emphasizing independent experimentation, only CLM participants reported elevated ability to design experiments. The present data comprise the first of five yearly analyses on this cohort of participants; long-term follow-up will determine whether the two program models are equally effective routes to research or other science-related careers for novice undergraduate neuroscientists.

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