Compression Modulus of Open-Celled Polyethylene Foams.

Permeability and Thermal Transport in Compressed Open-Celled Foams

A computational methodology is proposed to describe the fluid transport in compressed opencelled metallic foams. Various unit-cell foam geometries are numerically deformed under uniaxial loads using a finite element method. An algorithm is developed and implemented to deform the fluid domain mesh inside the unit-cell foam based on the deformed solid unit-cell geometry. Direct simulations of the...

New Algorithms for 3-D Imaging and Analysis of Open-Celled Foams

Open-celled foams are three-dimensional networks of polymeric cells. The mechanical properties of a foam depend on the size and geometry of its cells. Since foams have a three-dimensional polyhedral structure, the two-dimensional characterization techniques currently used provide limited accuracy. Nuclear magnetic resonance and x-ray tomography methods offer opportunities for three-dimensional ...

Crystalline polyethylene nanofibers with the theoretical limit of Young's modulus.

A highly crystalline polyethylene nanofiber is deflected by a cantilever under an atomic force microscope. The resulting approach and retract curves on both nanofiber and silicon substrate yield the Young's modulus of the nanofiber. The experiments show that the average Young's modulus of polyethylene nanofibers with diameters from 70 nm to 260 nm can be as high as 312 GPa.

Compression modulus of macroscopic fiber bundles

Young Modulus of Crystalline Polyethylene from ab Initio Molecular Dynamics

The Young modulus for crystalline polyethylene is calculated using ab initio molecular dynamics based on density functional theory in the local density approximation (DFT-LDA). This modulus, which can be seen as the ultimate value for the Young modulus of polyethylene fibers, is found to be 334 GPa. For the first time the modulus is evaluated ab initio (no bias from experimental data) with demo...