High Strain Rate Compressive Behavior of Polyurethane Resin and Polyurethane/Al2O3 Hollow Sphere Syntactic Foams

Polyurethane resins and foams are finding extensive applications. Seat cushions and covers in automobiles are examples of these materials. In the present work, hollow alumina particles are used as fillers in polyurethane resin to develop closed-cell syntactic foams. The fabricated syntactic foams are tested for compressive properties at quasistatic and high strain rates. Strain rate sensitivity is an important concern for automotive applications due to the possibility of crash at high speeds. Both the polyurethane resin and the syntactic foam show strain rate sensitivity in compressive strength. It is observed that the compressive strength increases with strain rate. The energy absorbed up to 10% strain in the quasistatic regime is 400% higher for the syntactic foam in comparison to that of neat resin at the same strain rate.

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Empirical Equations for a Study on Strain Rate Sensitivity of Polypropylene Syntactic Foam

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.143-144.303 ◽

2010 ◽

Vol 143-144 ◽

pp. 303-307

Author(s):

En Yang Wang ◽

Masaki Omiya

Keyword(s):

Strain Rate ◽

Strain Rate Sensitivity ◽

Viscoelastic Properties ◽

Elastic Moduli ◽

Syntactic Foam ◽

Rate Sensitivity ◽

Empirical Equations ◽

Syntactic Foams ◽

Nominal Strain Rate ◽

Nominal Strain

The strain rate sensitivity of polypropylene syntactic foams with polymer microballoons in the relative density from 0.5 to 0.8 is studied at the nominal strain rate ranged from 10-1 to 102 s -1. Two equations of matrix materials are introduced to represent the viscoelastic properties, and another two equations are proposed with respect to the parameters of matrix materials to estimate the elastic moduli and yield stresses of polymeric syntactic foams.

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Study on Plastic Deformation Behavior of Mo-10Ta under Ultra-High Strain Rate

Metals ◽

10.3390/met10091153 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1153

Author(s):

Ping Song ◽

Wen-Bin Li ◽

Yu Zheng ◽

Jiu-Peng Song ◽

Xiang-Cao Jiang ◽

...

Keyword(s):

Activation Energy ◽

High Strain Rate ◽

Strain Rate ◽

Strain Rate Sensitivity ◽

Deformation Behavior ◽

High Strain ◽

Rate Sensitivity ◽

Strain Rate Range ◽

Rate Range ◽

Strain Relationship

This study investigated the deformation behavior of the Mo-10Ta alloy with a strain rate range of 102–105 s−1. The Split Hopkinson pressure bar (SHPB) experiments were conducted to investigate the influence of deformation conditions on the stress-strain relationship and strain rate sensitivity of the material within a strain rate range of 0.001–4500 s−1. The Shaped Charge Jet (SCJ) forming experiments under detonation loading was conducted to clarify the dynamic response and microstructure evolution of the material within an ultra-high strain rates range of 104–105 s−1. Based on the stress-strain relationship of Mo-10Ta alloy at high temperature (286–873 K) and high strain rate (460–4500 s−1), the influence of temperature and strain rate on the activation energy Q was analyzed. The results indicate that the material strain rate sensitivity increased with the increase in strain rate and strain. Meanwhile, the activation energy Q decreased as the temperature and strain rate increased. The plasticity of the Mo-10Ta alloy under the condition of SCJ forming was substantially enhanced compared with that under quasi-static deformation. The material grain was also refined under ultra-high strain rate, as reflected by the reduction in grain size from 232 μm to less than 10 μm.

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