Experimental method for creep characterization of polymeric foam materials in media immersion

Gerald Pilz,Gerald Pinter,Florian Oesterreicher,Peter Guttmann

doi:10.1007/s11043-020-09457-x

Gerald Pilz, Gerald Pinter + Show 2 more

Open Access

https://doi.org/10.1007/s11043-020-09457-x

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Abstract

Polymeric flexible foam materials are widely used as damping materials in structural applications primarily to reduce unwanted system vibrations and related noise generation. Due to the viscoelastic nature of polymers and high compressibility of soft polymeric foams, their damping quality is strongly dependent on the overall loading situation, which occasionally means complex mechanical loading scenarios combined with specific ambient service conditions. In the case of superimposed constant compressive loading the deformation of the damping components is basically dependent on the fundamental creep tendency of certain material type and is also strongly influenced by service temperature and the surrounding contact media. Thus the chosen test methodology for proper creep characterization has to reflect these major influencing parameters.In this regard, a specific creep testing device was built up for the performance of small load compression creep experiments on soft foam specimens immersed in liquid media, which was mineral oil in the present study. Moreover, the thermo-mechanical behavior of the foam materials was investigated by dynamic-mechanical analysis (DMA). The resulting temperature-dependent modulus and damping characteristics showed a good correlation with the corresponding creep behavior, enabling a rough estimation of the creep tendency within corresponding temperature ranges.

Highlights

Noise reduction and energy saving issues are among the major challenges in the construction industry and machinery sector
For successful application of polymeric materials the overall loading situation in service such as the time- and temperature-dependent deformation behavior and possible media influence are of major importance
In the special case of polymeric foam materials the fundamental viscoelastic properties of the underlying polymer (Ferry 1980; Hellerich et al 2010; Ehrenstein and Theriault 2001) and load-dependent deformation of the specific cell structure is decisive for the overall deformation behavior (Gibson and Ashby 1999; Ashby 2006; Eaves 2004; Szycher 2013; Mills 2007)

Summary

Introduction

Noise reduction and energy saving issues are among the major challenges in the construction industry and machinery sector. In the special case of polymeric foam materials the fundamental viscoelastic properties of the underlying polymer (Ferry 1980; Hellerich et al 2010; Ehrenstein and Theriault 2001) and load-dependent deformation of the specific cell structure is decisive for the overall deformation behavior (Gibson and Ashby 1999; Ashby 2006; Eaves 2004; Szycher 2013; Mills 2007). According to the respective field of applications, commercial polyurethane foam materials are available in various formulations of the polymer type, closed or open cell structured in adjustable grades of density. All these parameters determine the deformation behavior of the elastomeric foam, which in general can be categorized as elastic and reversible. The bending and compression of cell walls and edges lead to approximately linear stress–strain correlation up to strains of about 5% (region I)

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