Age-aware constitutive materials model for a 3D printed polymeric foam

Abstract

Traditional open or closed-cell stochastic elastomeric foams have wide-ranging applications in numerous industries: from thermal insulation, shock absorbing/gap-filling support cushions, packaging, to light-weight structural and positional components. Recent developments in 3D printing technologies by direct ink-write have opened the possibility of replacing stochastic foam parts by more controlled printed micro-structures with superior stress-distribution and longer functional life. For successful deployment as mechanical support or structural components, it is crucial to characterize the response of such printed materials to long-term external loads in terms of stress-strain behavior evolution and in terms of irreversible structural and load-bearing capacity changes over time. To this end, here we report a thermal-age-aware constitutive model for a 3D printed close-packed foam structure under compression. The model is based on the Ogden hyperfoam strain-energy functional within the framework of Tobolsky two-network scheme. It accurately describes experimentally measured stress-strain response, compression set, and load retention for various aging times and temperatures. Through the technique of time-temperature-superposition the model enables the prediction of long-term changes along with the quantification of uncertainty stemming from sample-to-sample variation and measurement noise. All aging parameters appear to possess the same Arrhenius activation barrier, which suggests a single dominant aging mechanism at the molecular/network level.

Practical scale modification of oleogels by ultrasonic standing waves

“…When using the Storåker’s hyperelastic model, the first Piola-Kirchhoff stress during uniaxial compression or tension can be expressed as the following: [34] where λ is the stretch of the sample and parameters µ , α , and β describe the material properties of the sample. The α parameter has no intrinsic physical meaning [35] . The µ parameter represents the shear modulus of the material and the β parameter is related to the Poisson’s ratio ( ν ) through Eq.…”

Finite element analysis of compressive stress-strain relations in elastic materials for seat foundation

“…2). The Ogden foam model of second order (Mohanty and Mahapatra 2014;Maiti et al 2019) is sufficient to fit the experimental data (Fig. 4), and the model parameters are shown in Table 3.…”

Simulation Analysis of Equibiaxial Tension Tests for Rubber-like Materials

“…Physically based constitutive models can better account for hyperelasticity, visco-hyperelasticity, and damage phenomena [28]. Recently, these models have also been employed to represent the mechanical behavior of hydrogels and their composites [29,30], while refined hyperelastic models such as the hyperfoam model can accurately describe polymeric foam fabricated through 3D printing [31]. It is worth noting that factors like temperature and aging time may influence the model parameters [32].…”