The interlaminar interface of a crossply carbon fiber epoxy-matrix composite was found to be an impact sensor, with sensitivity to impact from 0.8 mJ to 5 J (though no indentation was observed) and to multiple (up to 35) impacts at the same energy. However, the sensing of a small impact after a large one was not effective if the small impact was much lower in energy than the large one. The high...

In this paper, static indentation and low velocity impact responses of a fully backed composite sandwich plate subjected to a rigid flat-ended cylindrical indenter/impactor are analytically investigated. The analysis is nonlinear due to nonlinear strain-displacement relation. In contrast to the existed analytical models for the indentation of composite sandwich plates, the stacking sequence of ...

We employ the Eshelby–Stroh formalism to study generalized plane strain infinitesimal deformations caused due to the indentation by a rigid circular cylinder of an elastic laminated plate with a throughthe-width rectangular void between two adjoining layers. Assuming that the void does not close during the indentation process, we find the indentation modulus (i.e., the slope of the indentation ...

The aim of this paper is to show that damage mechanisms can account for the response of lamellar bone to nanoindentation tests, with particular regards to the decrease of indentation stiffness with increasing penetration depth and to the loss of contact stiffness during the unloading phase of the test. For this purpose, indentation experiments on bovine cortical bone samples along axial and tra...

The application of the concept of the representative strain is often used in the stress-strain curve determination from indentation test because it can significantly simplify the analysis of the indentation response. A new methodology for determining the representative strain for Vickers indentation is presented in this article. Following a procedure based on finite element simulations of inden...

ÐThe response of lead zirconate titanate and barium titanate piezoelectric ceramics to spherical microindentation was investigated. Force vs penetration depth curves obtained from instrumented indentation reveal that the indentation sti€ness depends on the material condition (i.e. poled vs unpoled) and the type of indentor (i.e. electrically conducting vs insulating). Good agreement was found b...

Relaxation indentation experiments using atomic force microscopy (AFM) are used to obtain viscoelastic material properties of soft samples. The quasilinear viscoelastic (QLV) model formulated by Fung (1972, "Stress Strain History Relations of Soft Tissues in Simple Elongation," in Biomechanics, Its Foundation and Objectives, Prentice-Hall, Englewood Cliffs, NJ, pp. 181-207) for uniaxial compres...

Non-linear quasi-static axisymmetric indentation problem is studied for comparitive computational analysis between elasto-plastic parameters and mechanical behaviour of homogeneous engineering metal materials. Mathematical model, based on deformation theory version of J2 theory, leads to quasi-static elasto-plastic contact problem with unknown contact domain, depending on the value of a indenta...

In the present article, a new method for the determination of the hardening law using the load displacement curve, F–h, of a spherical indentation test is developed. This method is based on the study of the error between an experimental indentation curve and a number of finite elements simulation curves. For the smaller values of these errors, the error distribution shape is a valley, which is ...

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