The Influence of Density on the Value of Young’s Modulus for Dry Ice

Abstract

The efficiency of material consumption is an important consideration for production processes; this is particularly true for processes that use waste materials. Dry ice extrusion serves as a good example. An examination of the literature on this subject leads to an observation that the commercially available machines for dry ice compression are characterized by a high value of working force. Consequently, the effectiveness of the source consumption, electric energy and carbon dioxide, is very low. The subject of the experimental research presented in the article is the influence of the density of dry ice on the value of Young’s modulus. The first part of the article presents the test methodology and the special test stand that was developed to accommodate the unique characteristics of solid-state carbon dioxide. The test results present the characteristics of compaction and relaxation used as the basis for determining the value of Young’s modulus. Based on the test results obtained for various material density values, the characteristics of Young’s modulus are developed and graphed as a function of the density. The presented results are important for furthering the research on the development of extrusion and compaction processes; for example, using the Drucker–Prager/Cap model for the purpose of optimizing the geometrical characteristics of the work assembly components.

Experimental Investigation on the Effect of Dry Ice Compression on the Poisson Ratio

“…The equation obtained, in conjunction with the published results of research on the change in the value of Young's modulus as a function of density [33] z, can be used in numerical studies concerning the description of compaction processes using, for example:…”

“…The value of the Poisson ratio ν for a different degree of compression of the isotropic material was determined using the methodology described in [33]. It assumes that when the material is compacted in a closed chamber, the transverse strains ε x and ε y are equal to 0, and the strains σ x and σ y acting on the chamber's side walls are equal to each other.…”

Modelling of the Process of Extrusion of Dry Ice through a Single-Hole Die Using the Smoothed Particle Hydrodynamics (SPH) Method

“…It has been demonstrated that the value of this force depends on the die parameters and the coefficient of friction between the extruded material and the side walls of the die [18]. The value of Fe decreases as the process of extrusion proceeds and the density of the material ρ no longer increases as a result [20]. The graph in Figure 2 represents the change of F e as a function of ram displacement s, subdivided into three main phases of the change of force applied to extrude dry ice pellets.…”

“…It has been demonstrated that the value of this force depends on the die parameters and the coefficient of friction between the extruded material and the side walls of the die [18]. The value of Fe decreases as the process of extrusion proceeds and the density of the material ρ no longer increases as a result [20]. Compression of the material reduces the distances between the particles of the material observed as an increase in density ρ.…”

“…Compression of the material reduces the distances between the particles of the material observed as an increase in density ρ. As the value of ρ increases, so do the values of Young's modulus E, Poisson's ratio ν, and coefficient of friction µ [17,20,22]. The behaviour of the compressed material in Phase 2 may be accurately simulated with Drucker-Prager/Cap, Cam-Clay, and Mohr-Coulomb models [23][24][25].…”