Damping and cushioning characteristics of Polyjet 3D printed photopolymer with Kelvin model

2020 ◽  
pp. 0021955X2094497 ◽  
Author(s):  
Changfeng Ge ◽  
Denis Cormier ◽  
Brian Rice
Keyword(s):  
Hysteresis Loops ◽  
Damping Capacity ◽  
Compression Tests ◽  
Static Compression ◽  
Kelvin Model ◽  
Packaging Design ◽  
3D Printed ◽  
Printed Materials ◽  
Specific Damping Capacity ◽  
Quasi Static Compression

This study extends previous research on the measurement of a 3D printed photopolymer’s quasi-static cushion properties, to include cushion and damping properties due to impact loading. In order to develop analytical packaging models of 3D printed materials, it is essential to know how energy induced by shipping and handling is dissipated through damping. Compared to the cushion curve, investigating how damping influences packaging design is relatively unfamiliar to the packaging practitioner. This study uses experimentally derived hysteresis loops, from platen impact and quasi-static compression tests, to estimate specific damping capacities for 3D printed photopolymer. This study found that the “sticky” rubber like 3D printed photopolymers, based on a repeating pattern of Kelvin cells, were able to dissipate close to 100% of the input energy in platen impact tests and still return to their original dimensions after impact. In addition, this study shows that the specific damping capacity of the 3D printed structure increases significantly with strain rate.

Numerical analysis of mechanical properties of 3D printed aluminium components with variable core infill values

2020 ◽  
Vol 1 (103) ◽  
pp. 16-24
Author(s):  
P. Baras ◽  
J. Sawicki
Keyword(s):  
Numerical Analysis ◽  
Mechanical Strength ◽  
Reference Model ◽  
Reaction Force ◽  
Solid Material ◽  
Solid Core ◽  
Compression Tests ◽  
Element Analysis ◽  
Static Compression ◽  
3D Printed

Purpose: The purpose of this paper is to present numerical modelling results for 3D-printed aluminium components with different variable core infill values. Information published in this paper will guide engineers when designing the components with core infill regions. Design/methodology/approach: During this study 3 different core types (Gyroid, Schwarz P and Schwarz D) and different combinations of their parameters were examined numerically, using FEM by means of the software ANSYS Workbench 2019 R2. Influence of core type as well as its parameters on 3D printed components strength was studied. The “best” core type with the “best” combination of parameters was chosen. Findings: Results obtained from the numerical static compression tests distinctly showed that component strength is highly influenced by the type infill choice selected. Specifically, infill parameters and the coefficient (force reaction/volumetric percentage solid material) were investigated. Resulting total reaction force and percentage of solid material in the component were compared to the fully solid reference model. Research limitations/implications: Based on the Finite Element Analysis carried out in this work, it was found that results highlighted the optimal infill condition defined as the lowest amount of material theoretically used, whilst assuring sufficient mechanical strength. The best results were obtained by Schwarz D core type samples. Practical implications: In the case of the aviation or automotive industry, very high strength of manufactured elements along with a simultaneous reduction of their wight is extremely important. As the viability of additively manufactured parts continues to increase, traditionally manufactured components are continually being replaced with 3D-printed components. The parts produced by additive manufacturing do not have the solid core, they are rather filled with specific geometrical patterns. The reason of such operation is to save the material and, in this way, also weight. Originality/value: The conducted numerical analysis allowed to determine the most favourable parameters for optimal core infill configurations for aluminium 3D printed parts, taking into account the lowest amount of material theoretically used, whilst assuring sufficient mechanical strength.

Application of Fractional Derivatives to Modeling the Quasi-Static Response of Polyurethane Foam

2003 ◽  
Author(s):  
Rong Deng ◽  
Patricia Davies ◽  
Anil K. Bajaj
Keyword(s):  
System Identification ◽  
Polyurethane Foam ◽  
Elastic Model ◽  
Compression Tests ◽  
Static Compression ◽  
Identification Method ◽  
Dissipative Effects ◽  
Identification Technique ◽  
Nonlinear Elastic ◽  
Quasi Static Compression

A fractional derivative model of dissipative effects is combined with a nonlinear elastic model to model the response of polyurethane foam in quasi-static compression tests. A system identification method is developed based on a separation of the elastic and viscoelastic parts of the response, which is possible because of symmetries in the imposed deformation timehistory. Simulations are used to evaluate the proposed identification method when noise is present in the response. The system identification technique is also applied with some success to experimental data taken from several compression experiments on two types of polyurethane foam blocks.

scholarly journals Relationships of Egg Specific Gravity and Shell Thickness to Quasi-static Compression Tests

1976 ◽  
Vol 55 (4) ◽  
pp. 1282-1289 ◽  
Author(s):  
Malik M. Ahmad ◽  
G.W. Froning ◽  
F.B. Mather ◽  
L.L. Bashford
Keyword(s):  
Specific Gravity ◽  
Shell Thickness ◽  
Compression Tests ◽  
Static Compression ◽  
Quasi Static Compression

Dynamic Compression Behavior of Lotus-Type Porous Iron

2010 ◽  
Vol 658 ◽  
pp. 193-196
Author(s):  
Masakazu Tane ◽  
Tae Kawashima ◽  
Keitaro Horikawa ◽  
Hidetoshi Kobayashi ◽  
Hideo Nakajima
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Testing Machine ◽  
Porous Iron ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Static Compression ◽  
Plateau Stress ◽  
Stress Region ◽  
Quasi Static Compression

Dynamic and quasi-static compression tests were conducted on lotus-type porous iron with porosity of about 50% using the split Hopkinson pressure bar method and universal testing machine, respectively.　In the dynamic compression parallel to the pore direction, a plateau stress region appears where deformation proceeds at nearly constant stress, while the plateau stress region does not appear in the quasi-static compression. The plateau stress region is probably caused by the buckling deformation of matrix iron which occurs only in the dynamic compression. In contrast, the compression perpendicular to the orientation direction of pores exhibits no plateau-stress regions in the both dynamic and quasi-static compression.

Experimental Study on High Damping Rubber Under Combined Action of Compression and Shear

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Tinard Violaine ◽  
Nguyen Quang Tam ◽  
Fond Christophe
Keyword(s):  
Static Load ◽  
Mullins Effect ◽  
Compression Tests ◽  
Static Compression ◽  
Cyclic Shear ◽  
Combined Action ◽  
Loading Tests ◽  
High Damping Rubber ◽  
Quasi Static Compression ◽  
Time Dependance

High damping rubber (HDR) is used in HDR bearings (HDRBs) which are dissipating devices in structural systems. These devices actually have to support permanent static load in compression and potential cyclic shear when earthquakes occur. Mastering the behavior of bearings implies an accurate understanding of HDR response in such configuration. The behavior of HDR is, however, complex due to the nonlinearity and time dependance of stress–strain response and especially Mullins effect. To the authors' knowledge, tests on HDR under combined quasi-static compression and cyclic shear (QC-CS) have not been performed with regard to Mullins effect yet. The purpose of this study is thus to assess experimentally Mullins effect in HDR, especially under QC-CS. In order to achieve this aim, cyclic tensile and compression tests were first carried out to confirm the occurrence of Mullins effect in the considered HDR. Then, an original biaxial setup allowing testing HDR specimen under QC-CS was developed. This setup enables us to identify Mullins effect of the considered HDR under this kind of loading. Tests carried out with this setup were thus widened to the study of the influence of compression stress on shear response under this loading, especially in terms of shear modulus and density of energy dissipation.

Effect of Laser Forming on the Energy Absorbing Behavior of Metal Foams

2021 ◽  
pp. 1-29
Author(s):  
Tom Zhang ◽  
Yubin Liu ◽  
Nathan Ashmore ◽  
Wayne Li ◽  
Y. Lawrence Yao
Keyword(s):  
Metal Foam ◽  
Laser Forming ◽  
Compression Tests ◽  
Forming Process ◽  
Static Compression ◽  
Closed Cell ◽  
Similarities And Differences ◽  
Energy Absorbing ◽  
The Impact ◽  
Quasi Static Compression

Abstract Metal foam is light in weight and exhibits an excellent impact absorbing capability. Laser forming has emerged as a promising process in shaping metal foam plates into desired geometry. While the feasibility and shaping mechanism has been studied, the effect of the laser forming process on the mechanical properties and the energy absorbing behavior in particular of the formed foam parts has not been well understood. This study comparatively investigated such effect on as-received and laser formed closed-cell aluminum alloy foam. In quasi-static compression tests, attention paid to the changes in the elastic region. Imperfections near the laser irradiated surface were closely examined and used to help elucidate the similarities and differences in as-received and laser formed specimens. Similarly, from the impact tests, differences in deformation and specific energy absorption were focused on, while relative density distribution and evolution of foam specimens were numerically investigated.

scholarly journals Effect of addition of HTa to Al/PTFE under quasi-static compression on the properties of the developed energetic composite material

RSC Advances ◽  
2021 ◽  
Vol 11 (15) ◽  
pp. 8540-8545
Author(s):  
Xinxin Ren ◽  
Yuchun Li ◽  
Junyi Huang ◽  
Jiaxiang Wu ◽  
Shuangzhang Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Compression Tests ◽  
Static Compression ◽  
Reactive Materials ◽  
Reaction Characteristics ◽  
Quasi Static Compression

To study the mechanical properties and reaction characteristics of Al/HTa/PTFE reactive materials under quasi-static compression, five types of Al/HTa/PTFE specimens with different HTa contents were prepared for quasi-static compression tests.

PHYSICAL PROPERTIES OF EGGSHELLS: A COMPARISON OF THE PUNCTURE AND COMPRESSION TESTS FOR ESTIMATING SHELL STRENGTH

1977 ◽  
Vol 57 (2) ◽  
pp. 329-338 ◽  
Author(s):  
J. R. HUNT ◽  
PETER W. VOISEY ◽  
B. K. THOMPSON
Keyword(s):  
Shell Thickness ◽  
Shear Fracture ◽  
Compression Fracture ◽  
Compression Tests ◽  
Fracture Force ◽  
Static Compression ◽  
Fracture Properties ◽  
Puncture Force ◽  
Increase In Accuracy ◽  
Quasi Static Compression

Quasi-static compression and puncture methods of measuring eggshell strength were compared by testing consecutive eggs from each of 89 birds alternately until eight eggs per bird were tested by each method. Results indicated that the tensile and shear fracture properties of the shell material were linearly related to each other, and to shell thickness and specific gravity. Both puncture force and compression fracture force were significantly different on a between-hen basis even when adjusted for shell thickness. Puncture force was more closely related to shell thickness on a between-egg basis than was compression fracture force. Puncture force was not related to shell thickness on a within-egg basis. The increase in accuracy gained from repeated puncture measurements on a within-egg basis was discussed.

Mechanical Resistance Improvement of Oxidized Metallic Hollow Spheres Stacking

2011 ◽  
Vol 62 ◽  
pp. 117-123
Author(s):  
Cecile Davoine ◽  
Sebastien Mercier ◽  
F. Popoff ◽  
A. Götzfried
Keyword(s):  
Hollow Spheres ◽  
Relative Weight ◽  
Small Samples ◽  
Mechanical Resistance ◽  
Compression Tests ◽  
Mechanical Stiffness ◽  
Significant Deterioration ◽  
Static Compression ◽  
Oxidation Mechanisms ◽  
Quasi Static Compression

The oxidation of stainless steel hollow spheres stacking has been studied at 800, 900 and 1,000°C in laboratory air in the range of 200h. The experimental results based on the relative weight gain of oxidized samples revealed an effect of the sphere’s size over the kinetic of oxidation: the quicker oxidation of the material constitued by smallest spheres suggests that the ratio of exposed surface is preponderant in the oxidation mechanisms. A quasi total transformation of the metal into oxides has been observed after 100h at 1000°C. Some simple quasi-static compression tests highlighted a significant deterioration in mechanical resistance for samples oxidized for 100h at 900 and 1,000°C. The global collapse of the oxidized samples could be imputed to the presence of oxides into the shells porosities by implying a decrease of their ductility. In order to improve the mechanical resistance of oxidized hollow spheres stacking, the adding of a dense metallic undercoat is proposed. The concept is tested by producing small samples of nickel-based hollow spheres stacking. The observation of oxidized samples shows that the shell of hollow spheres are not totally oxidized, providing a continuous metallic squeletton beneficial for mechanical stiffness at high temperatures.

Effect of infill pattern, density and material type of 3D printed cubic structure under quasi-static loading

2020 ◽  
pp. 095440622097166
Author(s):  
Quanjin Ma ◽  
MRM Rejab ◽  
A Praveen Kumar ◽  
Hao Fu ◽  
Nallapaneni Manoj Kumar ◽  
...  
Keyword(s):  
Research Work ◽  
Compressive Loading ◽  
Compression Tests ◽  
Static Compression ◽  
Material Type ◽  
Pattern Density ◽  
Pattern Structures ◽  
3D Printed ◽  
Cubic Structure ◽  
Energy Absorbing

The present research work is aimed to investigate the effect of infill pattern, density and material types of 3D printed cubes under quasi-static axial compressive loading. The proposed samples were fabricated though 3D printing technique with two different materials, such as 100% polylactic acid (PLA) and 70% vol PLA mixed 30% vol carbon fiber (PLA/CF). Four infill pattern structures such as triangle, rectilinear, line and honeycomb with 20%, 40%, 60%, and 80% infill density were prepared. Subsequently, the quasi-static compression tests were performed on the fabricated 3D printed cubes to examine the effect of infill pattern, infill density and material types on crushing failure behaviour and energy-absorbing characteristics. The results revealed that the honeycomb infill pattern of 3D printed PLA cubic structure showed the best energy-absorbing characteristics compared to the other three infill patterns. From the present research study, it is highlighted that the proposed 3D printed structures with different material type, infill pattern and density have great potential to replace the conventional lightweight structures, which could provide better energy-absorbing characteristics.

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