Flexible Polyurethane (PU) foam samples with different densities and chemical formulations were tested in quasi-static stress-strain compression tests. The compression tests were performed using the Lloyd LR5K Plus instrument at fixed compression strain rate of 0.033 s-1 and samples were compressed up to 70% compression strains. All foam samples were tested in the foam rise direction and their ...

An image compression system is proposed, where compression is trivially accomplished by minimally redundant acquisition, but decoding requires a nonlinear estimation step. The performance of this system is evaluated on examples and by studying the operational rate-distortion curves for a simple source model.

A quantum equation-of-state model is presented and applied to the calculation of high-pressure shock Hugoniot curves beyond the asymp-totic fourfold density, close to the maximum compression where quantum effects play a role. An analytical estimate for the maximum attainable compression is proposed. It gives a good agreement with the equation-of-state model.

In the hot compression test friction has a detrimental influence on the flow stress through the process and therefore, correcting the deformation curve for real behavior is very important for both researchers and engineers. In this study, a series of compression tests were simulated using Abaqus software. In this study, it has been employed the Taguchi method to design experiments by the factor...

Based on elastic considerations, a new four parameter model of the hydrostatic compression curves of sandy soils is presented. Using a unique set of parameters, this model is capable of accurately representing the infinite family of compression curves that result when soil is subjected to stresses below particle breakage. The parameters are readily estimated from two hydrostatic tests conducted...

In this paper, crashworthiness characteristics of conical steel tubes stiffened by annular rings and rigid polyurethane foam are investigated. For this purpose, wide circumferential rings are created from the outer surface of the conical tube at some determined areas along tube length. In fact, this method divides a long conical tube into several tubes of shorter length. When this structure is ...