Variation of Mechanical Characteristics of Polyurethane Foam: Effect of Test Method

Abstract

Polyurethane foam (PUF), a representative insulation material, not only prevents heat conduction but can also support a load. Particular interest in rigid PUF proliferated over the past several years in fields where extreme environments are applied. A closed-cell structure which forms the interior of rigid PUF serves to maximize the utilization of these polymeric foams. Rigid PUF is more sensitive to external conditions such as temperature or restraint than other structural materials such as steel. Depending on the market trends in which utilization of a cryogenic environment is expanding, the tendency of material behavior resulting from the binding effect also needs to be investigated. However, most conventional compression test method standards applicable to rigid PUF do not adequately reflect the restraints. Therefore, this study proposes a method for evaluating the mechanical performance of materials in a more reliable manner than that of conventional tests. Experimental observation and analysis validated this compression evaluation method in which constraints are considered. Consequently, the compressive strength of rigid PUF compared to the results of the conventional test showed a difference of up to 0.47 MPa (approximately 23%) at cryogenic temperatures. This result suggests that there are important factors to consider when assessing performance from a material perspective in an environment where rigid PUF insulation is utilized. It is believed that the test methods newly proposed in this study will provide an experimental framework that can be applied to the evaluation criteria of material properties and reflected in structural design.

Behaviour of Polymer Filled Composites for Novel Polymer Railway Sleepers

“…A solid component made with polyurethane (PU) based resin was used as a core material of sleeper (Figure 2a). The typical compressive strength and compressive modulus of PU foam are 1 MPa and 16 MPa, respectively [15]. Two types of GFRP fabrics such as uniaxial (0 direction and 600 gsm) and triaxial (0/+45/−45 directional fibres and 823 gsm) were used to fabricate outer layer of the core.…”

Fracture toughness of rigid polymeric foams: A review

“…The testing methods for mechanical characterization of polymeric materials are described in Landrock, 58 Brown, 59,60 Ward and Sweeney 61 and Park et al 62 However, up to now, there are no standards for fracture toughness determination of polymeric foams. Most of the experiments were performed using the plane strain fracture toughness of plastic materials procedure from ASTM D5045‐99 63…”

Experimental research of absorption properties of rigid foam filled circular seamless tube energy absorber under quasi-static axial load

“…This diagram shows that increasing of density causes a slight increase of EA in a whole region, while the SEA slightly increases up to density of 170 kg/m 3 and then starts to decrease. Mechanical properties for different density of PU foam are taken from the papers [28][29][30][31]. Possible of using different methods and certain errors during determination of characteristics of PU foam can be reason of slightly decreasing of EA and SEA from density 100 until 150 kg/m 3 .…”

“…Table 3 contains key parameters obtained by numerical simulations of shrinking process using different values of tube wall thickness and constant value of density of PU foam (170 kg/m 3 ) as well as different values of density of PU foam and constant value of wall thickness of 2.5 mm. Mechanical properties in FE analyses, for different density of PU foam, were taken from the research papers [27][28][29][30][31] and implemented in the developed numerical model.…”