Probabilistic approach to evaluate dynamic and static strength of quasi-brittle materials through high-rate testing

Author(s):  
Grigory Volkov ◽  
Ivan Smirnov
1997 ◽  
Vol 07 (C3) ◽  
pp. C3-453-C3-458 ◽  
Author(s):  
G. M. Swallowe ◽  
J. O. Fernandez ◽  
S. Hamdan

Author(s):  
ADRIAN GOMEZ ◽  
SURESH KESHAVANARAYANA ◽  
LUIS CASTILLO ◽  
ASWINI KONA ◽  
AKHIL BHASIN ◽  
...  

Landslides ◽  
2020 ◽  
Vol 17 (10) ◽  
pp. 2469-2481
Author(s):  
Judith Uwihirwe ◽  
Markus Hrachowitz ◽  
Thom A. Bogaard

Abstract Regional empirical-statistical thresholds indicating the precipitation conditions initiating landslides are of crucial importance for landslide early warning system development. The objectives of this research were to use landslide and precipitation data in an empirical-statistical approach to (1) identify precipitation-related variables with the highest explanatory power for landslide occurrence and (2) define both trigger and trigger-cause based thresholds for landslides in Rwanda, Central-East Africa. Receiver operating characteristics (ROC) and area under the curve (AUC) metrics were used to test the suitability of a suite of precipitation-related explanatory variables. A Bayesian probabilistic approach, maximum true skill statistics and the minimum radial distance were used to determine the most informative threshold levels above which landslide are high likely to occur. The results indicated that the event precipitation volumes E, cumulative 1-day rainfall (RD1) that coincide with the day of landslide occurrence and 10-day antecedent precipitation are variables with the highest discriminatory power to distinguish landslide from no landslide conditions. The highest landslide prediction capability in terms of true positive alarms was obtained from single rainfall variables based on trigger-based thresholds. However, that predictive capability was constrained by the high rate of false positive alarms and thus the elevated probability to neglect the contribution of additional causal factors that lead to the occurrence of landslides and which can partly be accounted for by the antecedent precipitation indices. Further combination of different variables into trigger-cause pairs and the use of suitable thresholds in bilinear format improved the prediction capacity of the real trigger-based thresholds.


2021 ◽  
pp. 12-22
Author(s):  
V. A. Sidorov ◽  
A. V. Sidorov ◽  
N. V. Gichun

The increase in the total number of machines in the middle of the 20th century led to a rise in the number of repair services and served as an impetus for the start of work to improve the reliability of mechanical equipment based on the statistical probabilistic approach, the provisions of terotechnology and methods of technical diagnostics. Maintaining machines and mechanisms in working condition has become quite expensive. On the other hand, reducing the cost of maintenance and repairs leads to a violation of the continuity of the technological cycle. Existing trends in mechanical engineering and in the general paradigm of the development of civilization indicate a tendency to reduce the durability of parts and units. The manufacture of products with a long service life becomes economically unviable, which is the essence of the paradox. The article considers the examples of implementation of various approaches to the operation of equipment during maintenance and repair. The prerequisites for the necessity of conducting repairs are analyzed. It is recommended to try to reach a compromise between the manufacturer and the consumer on the basis of long-term contracts for the supply of spare parts or the provision of equipment maintenance services. The urgency of the problem is further justified by the high rate of robotization, since robots also need to be repaired. In this regard, the authors express the hope that this article will be useful in solving the problem of the repair.


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