Compression Testing and Microstructure of Heat-Treatable Aluminum Periodic Cellular Metal

2006 ◽  
Vol 929 ◽  
Author(s):  
B. A. Bouwhuis ◽  
G. D. Hibbard
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Energy Density ◽  
Sheet Metal ◽  
Mechanical Performance ◽  
Weight Ratio ◽  
Resistance Mechanisms ◽  
Confined Compression ◽  
Wide Range ◽  
Out Of Plane

ABSTRACTPeriodic cellular metals (PCMs) can offer higher specific strengths and stiffnesses than conventional (i.e. stochastic) metallic foams. This study examines the effects of PCM microstructure and loading conditions on the mechanical performance.PCM cores with 95% open porosity were constructed from perforated 6061 aluminium alloy sheets using a perforation-stretching method. This method places planar, periodically-perforated sheet metal in an alternating-pin jig. The pins apply force out-of-plane, plastically deforming the sheet metal into a truss-like array of struts (i.e. metal supports) and nodal peaks (i.e. strut intersections). Micro-hardness profiles were taken in the PCM struts to investigate microstructural evolution during fabrication and after heat treatment.Truss cores were tested in two limiting uniaxial compression conditions. In the first, the PCM cores are placed between smooth compression platens where the nodes are laterally free and compressive forces are resisted through PCM node-bending (i.e. free compression). In the second, the PCM cores were placed between plates where the nodes are laterally confined and compressive forces are resisted through PCM beam-buckling (i.e. confined compression). Compression response was analyzed in terms of peak compressive strength, elastic modulus, and energy density absorbed upon densification; response values were used to illustrate the effect of compression test conditions. In addition, PCM cores were tested in the age-hardened state and annealed state to determine microstructural effects on compressive response.Analysis of PCM response in free- and confined-compression conditions indicates a greater force resistance in beam-buckling over node-bending resistance mechanisms. The compressive strength, elastic modulus, and energy density of heat-treatable AA6061 PCMs are be found to respond: 1) over a wide range of value, dependent on the microstructure; 2) over a wide range of value, dependent on the PCM compression conditions; and 3) equally, if not more repeatable and with higher compressive strength-to-weight ratio than conventional metal foams.

Comparative Study on the Elastic Modulus of Polymer Concrete

2015 ◽  
Vol 1129 ◽  
pp. 145-150
Author(s):  
Kyu Seok Yeon ◽  
Kwan Kyu Kim ◽  
Chul Young Kim ◽  
Jae Heum Yeon
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Goodness Of Fit ◽  
Unsaturated Polyester ◽  
Acrylic Resin ◽  
Prediction Equation ◽  
Polymer Concrete ◽  
Wide Range ◽  
Structural Applications ◽  
Using Data

Polymer concrete is used for a wide range of precast structural applications and repair works for existing infrastructures. For these applications, one of the key mechanical propertiesthatneed to be consideredis the elastic modulus. In this study, the relationship between elastic modulus and compressive strength of polymer concrete made with three different types of resin (i.e., unsaturated polyester resin, acrylic resin, and epoxy resin) is comprehensively investigated using data sets available from previous studies in order to develop a prediction equation for elastic modulus that can be generally applied to polymer concrete. Results showed that the equation developed under this study can be reasonably adopted for the predictions of polymer concrete's elastic modulus as a function of compressive strength because the prediction equation has a high goodness of fit asrepresented by a R2 value of 0.77

Mechanical Performance and In Vitro Studies of Hydroxyapatite/Wollastonite Scaffold for Bone Tissue Engineering

2011 ◽  
Vol 493-494 ◽  
pp. 855-860
Author(s):  
Sanosh Kunjalukkal Padmanabhan ◽  
Marina Carrozzo ◽  
Francesca Gervaso ◽  
Francesca Scalera ◽  
Alessandro Sannino ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Compressive Strength ◽  
Mechanical Performance ◽  
Weight Ratio ◽  
Fold Increase ◽  
In Vitro Bioactivity ◽  
Phase Purity ◽  
Before And After ◽  
Highly Porous

A highly porous (~90%) interconnected hydroxyapatite/wollastonite (HA/WS) scaffolds were prepared by polymeric sponge replica method using a slurry containing HA:Calcium silicate in the weight ratio of 50:50 and sintered at 1300 °C. The phase purity of the scaffolds were analyzed by using XRD. The pore size, pore structure, microstructure and elemental analysis of the scaffolds before and after SBF soaking were analyzed using SEM and EDS. In-vitro bioactivity and bioresorbability confirmed the feasibility of the developed scaffolds. The HA/WS scaffold shows two fold increase in the compressive strength compared to pure HA scaffold.

Preferential Site Precipitation and Subcell Stability in AA6061 Sandwich Cores

2006 ◽  
Vol 977 ◽  
Author(s):  
B. A. Bouwhuis ◽  
G. D. Hibbard
Keyword(s):  
Sheet Metal ◽  
Cross Sections ◽  
Mechanical Performance ◽  
Small Deformation ◽  
Collapse Mechanisms ◽  
Truss Core ◽  
Out Of Plane ◽  
Perforated Sheet ◽  
6061 Aluminium Alloy ◽  
Sandwich Core

AbstractPeriodic cellular metal (PCM) sandwich cores can be considered hybrids of the solid and gas type. These can be designed at both the architectural and microstructural levels. PCM cores with 95% open porosity have been constructed from perforated 6061 aluminium alloy (AA6061) sheets using a perforation-stretching method. This method places planar, periodically-perforated sheet metal in an alternating-pin jig. The pins apply force out-of-plane, plastically deforming the sheet metal into a truss-like array of struts (i.e. metal supports) and nodal peaks (i.e. strut intersections). The result is a non-uniform work-hardened profile exhibiting large deformation at the nodes and small deformation at the struts.For identical PCM architectures, this study looks at the interaction of microstructural strengthening mechanisms and the resultant performance of PCM truss cores. Beginning with fabrication, work-hardening induced a subcell network of dislocation tangles within the AA6061 matrix. Following this stage, a variety of microstructures were created through recovery, recrystallization and precipitation mechanisms. Microhardness measurements and electron back-scattered diffraction (EBSD) characterization were employed through truss core cross-sections in order to study the microstructural gradients of subcell size as well as interaction between subcells and precipitates in the truss cores. To determine the effect of microstructure on mechanical performance, PCM cores were compressed to study deformation and collapse mechanisms.The present data can be used to illustrate engineering at the architectural and microstructural levels to achieve a range of mechanical properties in a hybrid sandwich core.

scholarly journals Elastic Mechanical Properties of 45S5-Based Bioactive Glass–Ceramic Scaffolds

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3244 ◽  
Author(s):  
Francesco Baino ◽  
Elisa Fiume
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Shear Modulus ◽  
Glass Ceramic ◽  
Poisson’S Ratio ◽  
Mechanical Performance ◽  
Poisson's Ratio ◽  
Shear Moduli ◽  
Bioactive Scaffolds

Porosity is recognized to play a key role in dictating the functional properties of bioactive scaffolds, especially the mechanical performance of the material. The mechanical suitability of brittle ceramic and glass scaffolds for bone tissue engineering applications is usually evaluated on the basis of the compressive strength alone, which is relatively easy to assess. This work aims to investigate the porosity dependence of the elastic properties of silicate scaffolds based on the 45S5 composition. Highly porous glass–ceramic foams were fabricated by the sponge replica method and their elastic modulus, shear modulus, and Poisson’s ratio were experimentally determined by the impulse excitation technique; furthermore, the failure strength was quantified by compressive tests. As the total fractional porosity increased from 0.52 to 0.86, the elastic and shear moduli decreased from 16.5 to 1.2 GPa and from 6.5 to 0.43 GPa, respectively; the compressive strength was also found to decrease from 3.4 to 0.58 MPa, whereas the Poisson’s ratio increased from 0.2692 to 0.3953. The porosity dependences of elastic modulus, shear modulus and compressive strength obeys power-law models, whereas the relationship between Poisson’s ratio and porosity can be described by a linear approximation. These relations can be useful to optimize the design and fabrication of porous biomaterials as well as to predict the mechanical properties of the scaffolds.

One-Part Geopolymer Synthesis of Greek Fly Ash

2021 ◽  
Vol 894 ◽  
pp. 135-142
Author(s):  
Olga Andriana Panitsa ◽  
Dimitrios Kioupis ◽  
Glykeria Kakali
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Building Materials ◽  
Mechanical Performance ◽  
Analytical Techniques ◽  
Silica Content ◽  
Synthesis Process ◽  
Molar Ratios ◽  
Wide Range ◽  
Global Emissions

With the OPC industry being responsible for the 8% of CO2 global emissions, alternative, eco-friendly building materials, called geopolymers, have been in the center of research interest. Their broader use is limited due to the concentrated alkali solution that is involved in the synthesis process. In this study, a wide range of solid reagents are tested for the development of solid mixtures with suitable alkali and silica content that will substitute the corrosive activation solution. One-part geopolymers were synthesized using Greek fly ash as the aluminosilicate precursor. The produced samples were appropriately characterized by XRD, FTIR and SEM analytical techniques while the mechanical performance was evaluated through uniaxial compressive strength measurements. One-part geopolymers using anhydrous sodium silicates with molar ratios SiO2/Na2O ≤ 2 as solid activators, can successfully substitute the activation solution since they achieve identical mechanical performance to that of the two-part geopolymers (≥ 60 MPa).

scholarly journals Effect of Absorbent Foam Filling on Mechanical Behaviors of 3D-Printed Honeycombs

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2059
Author(s):  
Leilei Yan ◽  
Keyu Zhu ◽  
Yunwei Zhang ◽  
Chun Zhang ◽  
Xitao Zheng
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Energy Absorption ◽  
Unit Volume ◽  
Honeycomb Structure ◽  
Unit Mass ◽  
Out Of Plane ◽  
Foam Filling ◽  
3D Printed ◽  
Foam Filled

Polylactic acid (PLA) hexagonal honeycomb structures were fabricated by using 3D-printing technology. By filling with absorbent polymethacrylimide (PMI) foam, a novel absorbent-foam-filled 3D-printed honeycomb was obtained. The in-plane (L- and W-direction) and out-of-plane (T-direction) compressive performances were studied experimentally and numerically. Due to absorbent PMI foam filling, the elastic modulus, compressive strength, energy absorption per unit volume, and energy absorption per unit mass of absorbent-foam-filled honeycomb under L-direction were increased by 296.34%, 168.75%, 505.57%, and 244.22%, respectively. Moreover, the elastic modulus, compressive strength, energy absorption per unit volume, and energy absorption per unit mass, under W-direction, also have increments of 211.65%, 179.85, 799.45%, and 413.02%, respectively. However, for out-of-plane compression, the compressive strength and energy absorption per unit volume were enhanced, but the density has also been increased; thus, it is not competitive in energy absorption per unit mass. Failure mechanism and dimension effects of absorbent-foam-filled honeycomb were also considered. The approach of absorbent foam filling made the 3D-printed honeycomb structure more competitive in electromagnetic wave stealth applications, while acting simultaneously as load-carrying structures.

scholarly journals Characterization of the Mechanical Performance in Compression Perpendicular to the Grain of Insect-Deteriorated Timber

Buildings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 14 ◽  
Author(s):  
Maxime Verbist ◽  
Jorge M. Branco ◽  
Lina Nunes
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Mechanical Performance ◽  
Castanea Sativa ◽  
Visual Assessment ◽  
Small Samples ◽  
Compression Tests ◽  
Sweet Chestnut ◽  
Castanea Sativa Mill ◽  
Future Work

Among biological agents, insect attacks may cause severe degradation of timber structures in the service life of buildings which leads to lower mechanical performance and, thus, maintenance problems over time. Additionally, compression perpendicular to the grain always features a weak spot with respect to the long-term mechanical performance of timber members and joints. In the present work, the respective strength and elastic modulus were thus investigated for insect deteriorated wood. Following a standardized geometry, small samples degraded by anobiids were extracted from beams made of sweet chestnut wood (Castanea sativa Mill.) that were removed from service. Visual assessment of the external wood surfaces was then performed to identify areas infested by insects. Afterwards, destructive monotonic compression tests were carried out perpendicularly to the grain on the damaged area to determine the loss of compressive strength and elastic modulus. The experimental results showed that the loss of compressive strength and elastic modulus might be linearly correlated to the wood density loss for small samples infested by insects. Nonetheless, future work should focus on determining accurately the density loss in the insect-deteriorated part through non- or semi-destructive tests, in order to establish stronger relationships with the mechanical properties loss investigated.

scholarly journals Experimental investigation of cracking behaviors of ductile and brittle rock-like materials

2021 ◽  
Vol 15 (56) ◽  
pp. 16-45
Author(s):  
Hao Bai ◽  
Wei Du ◽  
Yundong Shou ◽  
Lichuan Chen ◽  
Filippo Berto
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Axial Stress ◽  
Geotechnical Engineering ◽  
Cementitious Materials ◽  
Epoxide Resin ◽  
Application Range ◽  
Wide Range ◽  
Similar Materials ◽  
Cracking Characteristics

The cracking characteristics of ductile rocks were studied by similar materials with sand, barite, epoxide resin, polyamide, silicone rubber and alcohol, while the cracking characteristics of brittle rocks were investigated by similar material with sand, barite, rosin and alcohol. In this paper, to enhance the application range of the rock-like materials in the field of geotechnical engineering model tests, the values of the elastic modulus and the compressive strength of the artificial rock-like materials are changed in a wide range by adjusting the amount of cementitious materials (epoxide resin, polyamide, rosin, etc). The elastic modulus, compressive strength and cracking characteristics were obtained from the complete axial stress–strain curves of the specimens made of similar materials, which were cast using the different mixture ratios. These experimental data can provide quantitative investigation on mixture ratios of similar materials of rocks to model the geotechnical engineering. Furthermore, the effect of mixture ratios on mechanical properties and crack propagation pattern of specimens were also investigated by the specimens with pre-existing flaws under uniaxial compressive tests

Dynamic Response of Magnesium Alloy and its Nanocomposite under High Strain Rate Compressive Loading

2013 ◽  
Vol 394 ◽  
pp. 20-25 ◽  
Author(s):  
Xiao Jing ◽  
Wei Shu Dong
Keyword(s):  
Compressive Strength ◽  
Magnesium Alloy ◽  
Strain Rate ◽  
Energy Absorption ◽  
Magnesium Alloys ◽  
Dynamic Properties ◽  
Dynamic Compression ◽  
Compressive Loading ◽  
Weight Ratio ◽  
Wide Range

Magnesium alloys due to their low density, high strength to weight ratio and good impact resistance have been increasingly used in automotive, aerospace and electronics industries. However, the poor ductility and low strength of magnesium alloys limit their usage in impact situations. The dynamic properties are critical to evaluate the materials response in impact situations. In this study, magnesium alloy AZ31B and its composite containing 1.0vol% SiC nanoparticles were subjected to quasi-static and dynamic compressive loading to investigate the influence of strain rate and the presence of nanoparticles on the mechanical behavior. The dynamic compressive behaviors of both materials have been examined over a wide range of strain rate between 700 s-1and 2800 s-1. Compared to quasi-static loading, both materials exhibit significantly higher yield stresses and compressive strength, much better ductility, and thus a higher energy absorption capacity under dynamic compression. Under dynamic loading, the flow stress of both materials first increases with increasing strain rate from 700 s-1to 2300 s-1but then it decreases when the strain rate is above 2300 s-1. In terms of nanoparticle addition, its influence on the enhancement of yield stress and ultimate compressive strength are notable while the ductility remains the same resulting in better energy absorption performance of nanocomposite. This indicates that the nanocomposite has potential to replace the existing magnesium alloys for various applications where impact/shock loads are encountered.

Experimental Study on the Mechanical Properties of Rubber Concrete

2014 ◽  
Vol 915-916 ◽  
pp. 685-689 ◽  
Author(s):  
Hong Quan Sun ◽  
Wen Hui Zhou ◽  
Chao Yi Wei
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Substitution Rate ◽  
Mechanical Performance ◽  
Replacement Rate ◽  
Conventional Concrete ◽  
Rubber Powder ◽  
Axial Compressive Strength ◽  
Relationship Of ◽  
The Relationship

With the methods of studying conventional concrete mechanical performance, the influence of concrete performance on the rubber powder replacement rate is investigated. Based on the test data, the relationship of between the elastic modulus and the rubber powder replacement rate is fitted. The results show that the concrete slump decreases with the rubber substitution rate increasing. The compressive strength of the cube of the concrete, the axial compressive strength and the elastic modulus go down in different degree with the increment of the rubber substitution rate.

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