On the Damping Properties of a Polyurea Elastomer

2014 ◽  
Vol 887-888 ◽  
pp. 21-25 ◽  
Author(s):  
Fabrizia Ghezzo ◽  
Xi Geng Miao ◽  
Chun Lin Ji ◽  
Ruo Peng Liu
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Energy Absorption ◽  
Mechanical Characterization ◽  
Environmental Engineering ◽  
Damping Properties ◽  
Structural Vibrations ◽  
Bulk Materials ◽  
Absorption Properties ◽  
Impact Events

The development of materials with high damping and energy absorption properties in the form of bulk materials or coatings is today a target for designing components and structures with improved durability and survivability to serve in fields such as aeronautical, mechanical, civil and environmental engineering. This paper presents the results of the dynamic mechanical characterization conducted on reinforced polyurea composites. The mechanical properties of two types of composite materials utilizing the polyurea elastomer as a matrix are compared with those of the pure polymer. The composite materials show a substantial increase of the damping ability. Such materials can be produced in the form of coatings and successfully applied for maximizing the damping of mechanical and structural vibrations or for limiting the damage effects of impact events on structures and components.

Correlation between Zirconium Addition and Compressive Properties of AZ31 Mg Alloy Foams

2011 ◽  
Vol 121-126 ◽  
pp. 75-79
Author(s):  
Bo Young Hur ◽  
Rui Zhao
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Mg Alloy ◽  
Compressive Properties ◽  
Absorption Properties ◽  
Compression Behavior ◽  
Foaming Agent ◽  
Az31 Mg Alloy ◽  
Absorption Characteristics ◽  
Zirconium Addition

The compressive behaviors of AZ31-Zr foams using Ca particles as thickening agent and CaCO3 powder as foaming agent were investigated in this study. The porosity was about 48.7%~72.9%, pore size was between 0.43~0.97 mm, and homogenous pore structures were obtained. Mechanical properties of AZ31 Mg alloy foams were investigated by means of UTM. The cellular AZ31 Mg foams possess superior comprehensive mechanical properties. The energy absorption characteristics and the effects of compression behavior on the energy absorption properties for the cellular AZ31 Mg foams have been investigated and discussed. The results show that with the addition of Zr, the Mg alloy foam has the highest energy absorption value of 16.26 MJ/m3 and the hardness value of 81.8 HV, which is much higher than that of the foams fabricated without Zr.

scholarly journals Philosophy of Selecting ASTM Standards for Mechanical Characterization of Polymers and Polymer Composites

2021 ◽  
Vol 58 (3) ◽  
pp. 247-256
Author(s):  
Sachin Sumathy Raj ◽  
Kuzmin Anton Michailovich ◽  
Krishnakumar Subramanian ◽  
Saravanan Sathiamoorthyi ◽  
Kannan Thanneerpanthalpalayam Kandasamy
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Composites ◽  
Mechanical Testing ◽  
Materials Science ◽  
Mechanical Characterization ◽  
Review Article ◽  
Testing Standards ◽  
Young Researchers

Mechanical characterization of newly developed polymers and composites are the basic measurements that are used to check the potential of the material towards its usage in various applications. Young researchers who are new to the field of materials science often find it difficult in selecting the specific testing standards for their novel materials. This review article provides a detailed explanatory of the various ASTM standards that are used for analyzing the basic mechanical properties of polymer composite materials. The standard dimensions of the test specimens and the mechanical testing parameters that are universally followed in different testing phases are illustrated for the ease of research.

Effect of Fiber Loading and Surface Treatment on the Mechanical Properties of Coconut Sheath Fiber Reinforced Epoxy Composites

2014 ◽  
Vol 984-985 ◽  
pp. 178-184
Author(s):  
K. Santhanam ◽  
A. Kumaravel
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Composite Materials ◽  
Alkali Treatment ◽  
Fiber Reinforced ◽  
Absorption Properties ◽  
Fiber Reinforced Composite ◽  
Fiber Loading ◽  
Fiber Properties ◽  
Reinforced Composite

In the present work coconut sheath fiber has been used to prepare the composite material with epoxy resin. First the untreated coconut fiber was used to prepare the composite material then the coconut sheath fibers were treated with NAOH to modify the fiber properties. Then the effect of fiber loading and alkali treatment were evaluated and investigated. The mechanical properties of alkali treated fibers found to be higher than the untreated coconut sheath fiber reinforced composite materials. The water absorption properties of alkali treated fibers were found to be higher than the untreated coconut sheath fiber reinforced composite materials.

scholarly journals Dynamic Mechanical Behavior of Hierarchical Resin Honeycomb by 3D Printing

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 19
Author(s):  
Huan Hong ◽  
Menglei Hu ◽  
Liansong Dai
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Mechanical Behavior ◽  
Energy Absorption ◽  
Dynamic Compression ◽  
Hierarchical Level ◽  
Absorption Properties ◽  
Static Compression ◽  
Collapse Strength ◽  
Different Levels

In this paper, surface projection micron stereo-lithography technology (PμSL) by 3D printing was used to prepare two resin honeycomb materials with different levels, and the mechanical behavior of these materials was studied. The quasi-static compression experiment and the dynamic compression experiment were carried out on the samples using the in situ micro-compression testing machine and the Split Hopkinson bar (SHPB) experimental equipment. The stress–strain curves of these materials at different strain rates were obtained, and the energy absorption characteristic of materials with two different levels were analyzed. This article reveals that the collapse strength and energy absorption properties of the materials are related to the hierarchical level of honeycomb. Multi-level hierarchical honeycomb (MHH) has higher collapse strength and better energy absorption properties than single-level hierarchical honeycomb (SHH). It turned out that increasing the hierarchical level of honeycomb could improve the mechanical properties of the materials. In the future development of products, the mechanical properties of hierarchical material by 3D printing can be further optimized through changing the level of the fractal structure.

scholarly journals Closed-Cell Powder Metallurgical Aluminium Foams Reinforced with 3 vol.% SiC and 3 vol.% Graphite

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 2031
Author(s):  
Jaroslav Kováčik ◽  
Martin Nosko ◽  
Natália Mináriková ◽  
František Simančík ◽  
Jaroslav Jerz
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Modulus Of Elasticity ◽  
Nominal Composition ◽  
Constant Density ◽  
Damping Properties ◽  
Compression Tests ◽  
Foaming Agent ◽  
Reinforcing Particles ◽  
Closed Cell

Closed-cell aluminium foams (nominal composition: AlSi12Mg0.6Fe0.3) were prepared by the powder metallurgical route (using 0.4 wt.% TiH2 untreated powder as the foaming agent). Pure foams and foams with the addition of 3 vol.% graphite or SiC powder were prepared. The microstructure and mechanical properties of the prepared aluminium foams containing reinforcing particles were investigated at constant density and compared to those of the pure foam. Vibration measurements were performed to determine the damping properties and modulus of elasticity of the foams. Uniaxial compression tests were performed to determine the following mechanical properties: collapse stress, efficiency of energy absorption, plateau length and densification strain of the foams. All the foams behaved in a brittle manner during compression. Finally, the effect of admixed graphite and SiC powders on the properties of the investigated foam was evaluated, discussed and modelled. The addition of powders changed all investigated properties of the foams. Only the efficiency of energy absorption at constant density was almost identical.

scholarly journals A Study of Some Mechanical Properties of a Category of Composites with a Hybrid Matrix and Natural Reinforcements

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 478 ◽  
Author(s):  
Marius Stănescu ◽  
Dumitru Bolcu
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Wheat Straw ◽  
Damping Properties ◽  
Hybrid Resin ◽  
Hybrid Matrix ◽  
Natural Resin

The current composite materials must meet a double challenge, one that involves obtaining mechanical properties suitable to the field of activity in which they are used and another one, equally important, that requires that they be renewable. In this paper, we have obtained a category of composite materials that have natural reinforcements (fabrics of flax, cotton, hemp, cattail leaves, and wheat straw). As a matrix, we have used three types of hybrid resin, in the composition of which we used the natural resin dammar, in different majority volume proportions. The differences, up to 100%, were represented by epoxy resin and its associated reinforcement, to generate a quick process of polymerization. We have measured certain mechanical properties and the damping properties of the three types of hybrid resin and of the composite materials under study. Based on these properties, we point out a few fields of activity where these composite materials can be used.

Aging of polymer composite materials under loading. (See Beginning in #10-2020)

2020 ◽  
pp. 2-12
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Composite ◽  
Polymer Composite Materials ◽  
Cyclic Loads ◽  
Reinforced Plastics ◽  
Water Exposure ◽  
Laboratory Conditions ◽  
Bending Loads ◽  
Moisture Conditions

A study review of aging polymer composite materials (PCM) under different heat-moisture conditions or water exposure with the sequential or parallel influence of static or cyclic loads in laboratory conditions is presented. The influence of tension and bending loads is compared. Conditions of the different load influence on parameters of carbon-reinforced plastics and glass-reinforced plastics are discussed. Equipment and units for climatic tests of PCM under loading are described. Simulation examples of indices of mechanical properties of PCM under the influence of environment and loads are shown.

Aging of polymer composite materials under loading

2020 ◽  
pp. 7-18
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Composite ◽  
Polymer Composite Materials ◽  
Cyclic Loads ◽  
Reinforced Plastics ◽  
Water Exposure ◽  
Laboratory Conditions ◽  
Bending Loads ◽  
Moisture Conditions

A study review of aging polymer composite materials (PCM) under different heat-moisture conditions or water exposure with the sequential or parallel influence of static or cyclic loads in laboratory conditions is presented. The influence of tension and bending loads is compared. Conditions of the different load influence on parameters of carbon-reinforced plastics and glass-reinforced plastics are discussed. Equipment and units for climatic tests of PCM under loading are described. Simulation examples of indices of mechanical properties of PCM under the influence of environment and loads are shown.

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