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Compression Behavior (compression + behavior)

Distribution by Scientific Domains

Polymers and Materials Science	75%

Selected Abstracts

Strength Effects in Micropillars of a Dispersion Strengthened Superalloy,

ADVANCED ENGINEERING MATERIALS, Issue 5 2010
Baptiste Girault
The present paper investigates the uniaxial compression behavior of highly alloyed, focused ion beam (FIB) manufactured micropillars, ranging from 200 up to 4000,nm in diameter. The material used was the Ni-based oxide-dispersion strengthened (ODS) alloy Inconel MA6000. Stress,strain curves show a change in slip behavior comparable to those observed in pure fcc metals. Contrary to pure Ni pillar experiments, high critical resolved shear stress (CRSS) values were found independent of pillar diameter. This suggests that the deformation behavior is primarily controlled by the internal obstacle spacing, overwhelming any pillar-size-dependent mechanisms such as dislocation source action or starvation. [source]

Negative Strain-rate Sensitivity in a Nanostructured Aluminum Alloy,

ADVANCED ENGINEERING MATERIALS, Issue 10 2006
Q. Han
The influence of strain rate in the range of 10,1 to 10,5 s,1 on the compression behavior of a cryomilled 5083 Al alloy is studied. The compression flow stress remains constant after an initial short strain hardening and a small stress dip, which indicates a dynamic saturation of dislocations. It is found that the compression flow stress increases with decreasing strain rate, which is believed to be attributed to dynamic strain aging. [source]

Global and local linear buckling behavior of a chiral cellular structure

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 3 2005
A. Spadoni
Abstract This paper investigates the flat-wise compression behavior of an innovative cellular structure configuration. The considered layout has a hexagonal chiral geometry featuring cylinders, or nodes, joined by ligaments, or ribs. The resulting assembly is characterized by a number of interesting properties that can be exploited for the design of alternative honeycombs or cellular topologies to be used in sandwich construction. The flat-wise strength of the chiral geometry is investigated through classical analytical formulas for the linear buckling of thin plates and shells and a bifurcation analysis performed on a Finite Element model. The analytical expressions predict the global buckling behavior and the resulting critical loads, and can be directly compared with the results obtained from the Finite Element analysis. In addition, the Finite Element model predicts local buckling modes, which should be considered to evaluate the possible development of localized plasticity. A sensitivity study is performed to evaluate the influence of the geometry of the chiral structure on its buckling strength. The study shows that the considered topology can offer great design flexibility, whereby several parameters can be selected and modified to improve the flat-wise performance. The comparison with traditional, hexagonal centro-symmetric structural configurations concludes the paper and demonstrates the enhanced performance and the potentials of chiral noncentro-symmetric designs. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Microstructure analysis of high performance fibers in compression

POLYMER ENGINEERING & SCIENCE, Issue 3 2003
Wansoo Huh
In order to understand the nature of kink band formation in high performance fibers, the compression behavior of pitch and PAN-based carbon fibers (P75S, T-50, T-300, and GY-70), and of polymeric fibers (DuPont Kevlar; PBZT; and PBO) was measured using a micro-scale compression apparatus in an optical microscope. With increasing compressive strain, kink band formation was observed and the number of kink bands per unit length (referred to as kink band density) was determined. By extrapolating to zero kink band density, the critical compressive strain for rigid-rod polymeric fibers was obtained and compared to that of the carbon fiber. Using the Euler buckling equation, a fundamental dimension of the buckling element for the compression of PBO and PBZT fibers was calculated to be a 0.42,0.57 µm diameter fibril, and not the smaller diameter microfibrils. [source]