The elastic modulus of an oral cancer cell line UM1 is investigated by nanoindentation in an atomic force microscope with a flat-ended tip. The commonly used Hertzian method gives apparent elastic modulus which increases with the loading rate, indicating strong effects of viscoelasticity. On the contrary, a rate-jump method developed for viscoelastic materials gives elastic modulus values which...

As the springback of sheet metal during unloadingmay cause deviation from a desired shape, accurately predicting springback is essential for the design of sheet stamping operations. Finite-element models have not been successful in predicting springback; hence there is a need for analytical models to make such predictions. In this study, a model based on differential strains after relief from t...

Article history: Received 26 February 2014 Received in final revised form 30 April 2014 Available online 4 June 2014

A macroscopic compression test utilizing a simple custom-built instrument was employed to measure polydimethylsiloxane (PDMS) elastic modulus. PDMS samples with varying crosslinking density were prepared with the elastomer base to the curing agent ratio ranging from 5 : 1 to 33 : 1. The PDMS network elastic modulus varied linearly with the amount of crosslinker, ranging from 0.57 MPa to 3.7 MPa...

BACKGROUND The mechanical properties of 1-2-year-old pediatric cranial bones and sutures and their influential factors were studied to better understand how the pediatric calvarium reacts to loading. MATERIAL AND METHODS Cranial bone and suture specimens were extracted from seven fresh-frozen human infant cadavers (1.5±0.5 years old). Eight specimens were obtained from each subject: two front...

in many cases, a torsional shaft may be a thick-walled radially inhomogeneous cylindrical object. the hollow shafts made of functionally graded materials (fgms) are such kind of compositions which were studied in this paper. cylindrical fg shafts are composed of ceramic and metallic parts with power function distribution across the radial direction. the ceramic phase is isotropic elastic and th...

Nanoindentation tests using the Berkovich indenter tip were performed on 50 and 200 nm thick polycrystalline gold films deposited on hard substrates. Gold film hardness increased with the indentation depth due to the influence of the substrate. A procedure based on the Joslin-Oliver method was introduced to correct for the substrate effect. The method utilizes the fact that the measured elastic...

OBJECTIVES To measure the mechanical property of prostatic tissues using a minimally motorized indenter and to determine whether measurable differences in mechanical property exist between cancerous and noncancerous tissues in an ex vivo experiment. METHODS A total of 552 sites from 46 prostate specimens taken during radical prostatectomy underwent an indentation experiment with a minimally m...

BACKGROUND The use of composites in dental restoration has been commonly criticized, due to their underwhelming mechanical properties. This problem may be solved partially by preheating. The present research aims to determine the effect of preheating on the mechanical properties of two different classes of composites. MATERIAL AND METHODS A Silorane-based (Silorane) and a Methacrylate-based (...

Understanding the controls on the elastic properties of reservoir rocks is crucial for exploration and successful production from hydrocarbon reservoirs. We studied the static and dynamic elastic properties of shale gas reservoir rocks from Barnett, Haynesville, Eagle Ford, and Fort St. John shales through laboratory experiments. The elastic properties of these rocks vary significantly between ...