Calculation of Metalwork Life with Allowance for Cyclic Degradation of Material in Operation

2016 ◽  
Vol 870 ◽  
pp. 725-729
Author(s):  
V. Mironov ◽  
O. Lukashuk

The article describes an alternative method of calculating durability and life of metal construction elements. Parameters of complete deformation diagram are used as a representative of the fatigue process. Such diagram is plotted when a small sample of material is stretched in a rigid load-applying unit. Determination of process kinetics from a mechanical experiment enhances possibilities for phenomenological description of constructional elements’ fatigue fracture. Proper usage of material cyclic degradation model in the stage of fatigue crack development is possible when one explicitly allows for anomalies of a constructional element’s surface layer properties. Within the scope of general concept of correlation between static and cyclic material properties a scheme for differentiating between a component’s surface layer and base metal properties is presented. Explicitly allowing for anomalies of a component’s surface layer properties makes it possible to calculate its durability and life within the unified model of material.

2019 ◽  
pp. 392-400 ◽  
Author(s):  
Gunnar Kleuker ◽  
Christa M. Hoffmann

The harvest of sugar beet leads to root tip breakage and surface damage through mechanical impacts, which increase storage losses. For the determination of textural properties of sugar beet roots with a texture analyzer a reliable method description is missing. This study aimed to evaluate the impact of washing, soil tare, storage period from washing until measurement, sample distribution and number of roots on puncture and compression measurements. For this purpose, in 2017 comprehensive tests were conducted with sugar beet roots grown in a greenhouse. In a second step these tests were carried out with different Beta varieties from a field trial, and in addition, a flexural test was included. Results show that the storage period after washing and the sample distribution had an influence on the puncture and compression strength. It is suggested to wash the roots by hand before the measurement and to determine the strength no later than 48 h after washing. For reliable and comparable results a radial distribution of measurement points around the widest circumference of the root is recommended for the puncture test. The sample position of the compression test had an influence on the compressive strength and therefore, needs to be clearly defined. For the puncture and the compression test it was possible to achieve stable results with a small sample size, but with increasing heterogeneity of the plant stand a higher number of roots is required. The flexural test showed a high variability and is, therefore, not recommended for the analysis of sugar beet textural properties.


2008 ◽  
Vol 44-46 ◽  
pp. 871-878 ◽  
Author(s):  
Chu Yang Luo ◽  
Jun Jiang Xiong ◽  
R.A. Shenoi

This paper outlines a new technique to address the paucity of data in determining fatigue life and performance based on reliability concepts. Two new randomized models are presented for estimating the safe life and pS-N curve, by using the standard procedure for statistical analysis and dealing with small sample numbers of incomplete data. The confidence level formulations for the safe and p-S-N curve are also given. The concepts are then applied for the determination of the safe life and p-S-N curve. Two sets of fatigue tests for the safe life and p-S-N curve are conducted to validate the presented method, demonstrating the practical use of the proposed technique.


1958 ◽  
Vol 4 (2) ◽  
pp. 120-126 ◽  
Author(s):  
David Seligson ◽  
Jean Marino
Keyword(s):  

Abstract An automatic pipeting device has been attached to the Van Slyke manometric apparatus for the determination of CO2. It has proved to be accurate, requires a small sample of serum, and is self-cleaning and rapid.


2015 ◽  
Vol 732 ◽  
pp. 389-392 ◽  
Author(s):  
Pavel Reiterman

The paper introduces an experimental program focused on the monitoring of water transport in surface layer of concrete aimed at monitoring the permeability of concrete, since concrete permeability is a property uniquely affecting durability of concrete. Introduced methods are complemented by experimental results and other traditional tests. These findings will serve to further optimization of the structure being created, thus ensuring its better aesthetic and functional characteristics.


2021 ◽  
pp. 30-34
Author(s):  
V.F. Bezjazychnyi ◽  
M.A. Prokofiev ◽  
F.R. Zhirnova

The method of calculating the strength of the joint with tension taking into account the technological conditions for processing the mating surfaces, which determine the quality indicators of the surface layer of the material of these surfaces: the surface roughness and the degree of their hardening, was described.


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