Mechanical response of pig skin under dynamic tensile loading

Abstract

a b s t r a c tUniaxial tensile experiments were performed on pig skin to investigate the tensile stressestrain response at both quasi-static and dynamic rates of deformation. A Kolsky tension bar, also called a split Hopkinson tension bar (SHTB), was modified to conduct the dynamic experiments. Semiconductor strain gages were used to measure the low levels of the transmitted signal from pig skin. A pulse shaper technique was used for generating a suitable incident pulse to ensure stress equilibrium and approximate constant strain rate in the specimen of a thin skin sheet wrapped around the ends of the bars for minimizing radial inertia. In order to investigate the strain-rate effect over a wide range of strain rates, quasi-static tests were also performed. The experimental results show that pig skin exhibits rate-sensitive, orthotropic, and non-linear behavior. The response along the spine direction is stiffer at lower rate but is less rate sensitive than the perpendicular direction. An Ogden model with two material constants is adopted to describe the rate-sensitive tensile behavior of the pig skin.

The analysis of forces needed for the suturing of elliptical skin wounds

“…This constitutive model consists of Ogden energy strain function and a relaxation function. The Ogden model is one of various strain energy functions and very often used for describing soft tissues [16,20]. The strain energy function is written in terms of the principal stretches as…”

A novel method for visualising and quantifying through-plane skin layer deformations

“…Even though shearing is induced in soft tissues in numerous applications and situations in everyday life, the study of shear deformation has received little attention in the biomechanics literature (Hollenstein et al, 2011;Horgan and Murphy, 2011), and little literature has concerned the cyclic deformation of skin tissue (Kang and Wu, 2011;Lim et al, 2011). Thus, until now only limited in vivo and in vitro data is available for dynamic shear moduli of (human) skin (Agache et al, 1980;Escoffier et al, 1989;Geerligs et al, 2011a;Holt et al, 2008); shear moduli ranging from 0.2 to 120 kPa have been reported.…”

Review of Experimental Techniques used to Study the Mechanical Behaviour of Biological Soft Tissues

“…Quasi-static tests have been performed by using standard universal testing machines [1][2][3][4][5][6][7][8][9][10][11] for testing porcine muscle [1], bovine brain tissue [2], bovine kidney tissue [3], porcine adipose tissue [4], polyurea elastomer [5], gelatin tissue simulant [6] under compressive loading, while bovine tendon [7], pig skin [8], human cadaveric gastro-colic ligament [9], EPDM soft rubber [10], and polymer RTM-6 soft material [11] under tensile loading.…”

“…Thus, it is essential to develop most reliable and flexible experimental methods to illustrate mechanical behaviour of soft materials at different intermediate rates of strain. [14] and liver tissues [15], bovine muscles [16], porcine muscles [1], bovine kidney tissue [3], porcine white adipose tissue [4], porcine trachea [17], EPDM rubber [10], polyurea [5] and gelatin bio-material [6] under dynamic compressive loading conditions, while bovine tendon [7], pig skin [8] This review summarizes important issues related with the application of SHPB in the characterization of soft tissues and soft materials. These issues are weak transmitted signals, constant rate of deformation, uniform loading on the specimen, specimen gripping methods and inertia effects.…”