Search results for "Mean stress"
showing 4 items of 4 documents
Agreement between body surface and rectal temperature in cats
2021
Measuring body temperature in cats is an essential part of every clinical examination. Typically, rectal temperature measurement is conducted, but the procedure is poorly tolerated, and it often triggers stress-related changes in physiological parameters like pulse rate and blood pressure. Therefore, non-contact infrared thermometers have been studied on a few body surface measurement sites. However, existing studies included only commercial thermometers, which do not guarantee the correct temperature readings. In this study, we applied a custom-made and calibrated infrared thermometer for measuring feline body surface temperature on easily-accessible measurement sites of the eye, gum, and …
Application of an energy model for fatigue life prediction of construction steels under bending, torsion and synchronous bending and torsion
2003
Abstract The paper contains a mathematical model of the material’s behaviour under cyclic loading taking into account the dynamics of the fatigue process, including the number of cycles to failure, induced by the mean stress value. The coefficients in the proposed model have been obtained from experimental tests under symmetrical and nonsymmetrical loading (with the stress ratio R =0). The proposed model has been used in order to modify an energy criterion with the aim of accounting for the influence of the mean stress on the fatigue life. The fatigue tests have been performed for structural steels 10HNAP and 18G2A subjected to cyclic bending, torsion and synchronous bending with torsion, b…
The influence of the mean stress on fatigue life of 10HNAP steel under random loading
2001
Abstract This paper contains the results of uniaxial random load fatigue tests with different mean values performed on 10HNAP steel specimens. The experimental fatigue life was compared with the life determined according to different methods of amplitude transformation of the cycles. Cycles were counted with the rain flow algorithm and damage was cumulated with the Palmgren–Miner hypothesis. It has been shown that in the case of “symmetric” stress histories with zero expected values, the mean values of selected cycles do not strongly influence the calculated fatigue life and transformation of the cycle amplitudes; hence, no mean stress correction for cycle mean values different from zero is…
Evolution of grain-size distribution of pumice sands in 1-D compression
2016
Abstract Crushing is one of the micromechanisms that govern the mechanical behaviour of sands at medium-high stresses. It depends on mineralogy, form and strength of single particle, mean stress level, coordination number, time, etc.. It causes changes of grain-size distribution, porosity, number and type of grain contacts, fabric, structure of the material, etc.. Results of an experimental research on the crushing of pumice sands compressed under 1-D conditions to vertical effective stresses σ′v up to 100MPa are reported here. They show marked crushing already at σ′v of about 200kPa. The evolution of the grain-size distribution can be represented by ΔDi= h/(K(1+C exp(–hlgσ′v))) in which ΔD…