High strain rate mechanical behavior of polyurea

J. dynamic behavior mater.

Jordan

2016

265

121

The mechanical properties of polymers are becoming increasingly important as they are used in structural applications, both on their own and as matrix materials for composites. It has long been known that these mechanical properties are dependent on strain rate, temperature, and pressure. In this paper, the methods for dynamic loading of polymers will be briefly reviewed. The high strain rate mechanical properties of several classes of polymers, i.e. glassy and rubbery amorphous polymers and semi-crystalline polymers will be reviewed. Additionally, time-temperature superposition for rate dependent large strain properties and pressure dependence in polymers will be discussed. Constitutive modeling and shock properties of polymers will not be discussed in this review.

Section: Intermediate Strain Ratesmentioning

confidence: 99%

Section: Rubbery Amorphous Polymersmentioning

confidence: 99%

High Strain Rate Mechanics of Polymers: A Review

J. dynamic behavior mater.

Jordan

2016

265

121

“…Hence, the effective use of a rubber can only be achieved when its dynamic mechanical properties are well characterized. Several studies have included high speed experiments on rubbers in compression and tension using the split Hopkinson bars [2][3][4] and newly developed techniques [5,6]. Although many improvements have been made to this traditional technique, the inherent softness of rubber produces experimental difficulties in achieving precise force measurements and a static stress equilibrium state.…”

Section: Introductionmentioning

confidence: 99%

The dynamic Virtual Fields Method on rubbers at medium and high strain rates

Yoon

2015

EPJ Web of Conferences

Abstract. Elastomeric materials are widely used for energy absorption applications, often experiencing high strain rate deformations. The mechanical characterization of rubbers at high strain rates presents several experimental difficulties, especially associated with achieving adequate signal to noise ratio and static stress equilibrium, when using a conventional technique such as the split Hopkinson pressure bar. In the present study, these problems are avoided by using the dynamic Virtual Fields Method (VFM) in which acceleration fields, clearly generated by the non-equilibrium state, are utilized as a force measurement with in the frame work of the principle of virtual work equation. In this paper, two dynamic VFM based techniques are used to characterise an EPDM rubber. These are denoted as the linear and nonlinear VFM and are developed for (respectively) medium (drop-weight) and high (gas-gun) strain-rate experiments. The use of the two VFMs combined with high-speed imaging analysed by digital imaging correlation allows the identification of the parameters of a given rubber mechanical model; in this case the Ogden model is used.

“…More recently, research programs that study the combined effects of temperature and strain rate have made significant steps in providing better understanding of the physics behind the observed response [1,2], and also in modeling this response [3,4]. However, limited data are available in tension, and even more limited are data describing both the compressive and tensile response of the same polymer [5][6][7][8]. In studies that examine tensile response, there are, often, large gaps in the strain rate dependence.…”

Section: Introductionmentioning

confidence: 99%

High strain rate tensile and compressive effects in glassy polymers

Jordan

Woodworth

2012

EPJ Web of Conferences

Abstract. Polymers are increasingly used in impact and complex high rate loading applications. Generally, the mechanical response of glassy polymers under high strain rates has been determined in compression. Some research programs have studied the combined effects of temperature and strain rate, still primarily in compression, providing better understanding of the physics behind the observed response and enhancing the models for these materials. However, limited data are available in tension, and even more limited are data describing both the compressive and tensile response of the same glassy polymer. This paper investigates the compressive and tensile response of glassy polymers across a range of stain rates from quasi-static to dynamic. Experimental results from dynamic mechanical analysis, quasi-static compression and tension, and split Hopkinson tension/pressure bars on several representative glassy polymers will be presented. The pressure dependant yield in these materials will be discussed through comparison of the tensile and compressive yield stresses.