Investigation of the Constitutive Model of W/PMMA Composite Microcellular Foams

Abstract

Investigating the constitutive relationship of a material can provide better understanding of the mechanical properties of a material and has an irreplaceable effect on optimizing the performance of a material. This paper investigated a constitutive model for tungsten/polymethyl-methacrylate (W/PMMA) composite microcellular foams prepared by using melt mixing and supercritical carbon dioxide foaming. The stress-strain relationships of these foams with different W contents were measured under static compression. The elastic modulus and compressive strength values of the foams were remarkably greater than those of the pure PMMA foams: at a W content of 20 wt %, these values were increased by 269.1% and 123.9%, respectively. Based on the Maxwell constitutive model, the relevant coefficients were fitted according to the experimental data of different relative densities and W contents in quasi-static compression. According to the numerical relationships between the relevant coefficients and the relative densities and W contents, the quasi-static mechanical constitutive model of W/PMMA composite microcellular foams with W contents of 0~60 wt % and relative densities of 0.15~0.55 were predicted. This study provided basic data for the optimal design of the W/PMMA composite microcellular foams and proposed a method for investigating the mechanical properties of composite microcellular foam materials.

A Review on Mechanical Models for Cellular Media: Investigation on Material Characterization and Numerical Simulation

“…The research of cellular media is growing rapidly and has been widely used in fields of packaging boxes, transportation, daily necessities, industrial manufacturing, and aerospace. There will be more applications in the future: The deformation mode and failure mechanism of cellular media under explosive loading and ultrahigh strain rates, gradient cellular material (gradient mode) structural design and performance optimization [ 18 , 57 , 71 , 154 , 155 , 156 , 157 , 158 , 159 ], and functional foam composite materials (e.g., doped metal particles, carbon nanotubes, and graphene) [ 21 , 160 , 161 , 162 , 163 ] are the keys to future research on cellular media. Expand the mechanical constitutive models of cellular media to suitable for various complex loads, and propose more constitutive models to understand the multifunctional performance of cellular media.…”

“…The deformation mode and failure mechanism of cellular media under explosive loading and ultrahigh strain rates, gradient cellular material (gradient mode) structural design and performance optimization [ 18 , 57 , 71 , 154 , 155 , 156 , 157 , 158 , 159 ], and functional foam composite materials (e.g., doped metal particles, carbon nanotubes, and graphene) [ 21 , 160 , 161 , 162 , 163 ] are the keys to future research on cellular media.…”

Correlation Between the Structure and Compressive Property of PMMA Microcellular Foams Fabricated by Supercritical CO2 Foaming Method

“…A collection of experiments, including four different foaming temperatures (50, 80, 110, 130 • C) and six different foaming pressures (8,13,18,23,28,32 MPa) were performed using a three-stage process. In the first stage, the samples were saturated under fixed gas pressure and die temperature conditions for at least 8 h. The next stage was a desorption process, in which the pressure decreased to room pressure in less than 10 s, and the gas in the polymer began to nucleate and grow.…”

“…However, the discussion was limited to a void fraction of 0.95, with no discussion of other densities or fractions. Moreover, the underlying reasons for the structure effect have rarely been discussed [18,[23][24][25].…”

Tungsten-based polymer composite, a new lead-free material for efficient shielding of coupled neutron-gamma radiation fields: A FLUKA simulation study

“…PMMA (C 5 H 8 O 2 ) is a transparent thermoplastic with good tensile strength. Preparation of W-PMMA composite microcellular foam, with different W concentration, using melt-mixing and supercritical carbon dioxide foaming methods has been reported [14] with remarkably increased mechanical strength than those of pure PMMA. A recent work evaluated the gamma attenuation performance of Bi 2 O 3 metal particles dispersed in PMMA matrix [15].…”