Influence of Material Damage on the Parameters of a Nonlinear Flexible Wave Which Spread in a Beam

Author(s):  
Dmitry M. Brikkel ◽  
Vladimir I. Erofeev
2006 ◽  
Vol 99 (12) ◽  
pp. 124913 ◽  
Author(s):  
Jan Herrmann ◽  
Jin-Yeon Kim ◽  
Laurence J. Jacobs ◽  
Jianmin Qu ◽  
Jerrol W. Littles ◽  
...  

2021 ◽  
Vol 111 (07-08) ◽  
pp. 495-500
Author(s):  
Eckart Uhlmann ◽  
Tobias Holznagel ◽  
Sebastian Ospina Mora

Herausforderungen bei der spanenden Bearbeitung von CFK sind unerwünschte Materialschädigungen im Bauteil sowie hohe Werkzeugverschleißraten. Für diese Arbeit wurden zerstörende Analogversuche an CFK und diamantbeschichteten Hartmetallproben durchgeführt und die Körperschallmesssignale analysiert. Die eingehende Untersuchung der Messwerte aus den Analogversuchen kann zu einer datengetriebenen Parametrierung einer körperschallbasierten Prozessüberwachung für die Fräsbearbeitung von CFK beitragen.   Challenges in machining CFRP are unwanted material damage in the component and high tool wear rates. For this work, destructive analogy experiments were carried out on CFRP and diamond-coated milling tools while analyzing the acoustic emission measurement signals. The detailed examination of the measured values from the analogy experiment can contribute to a data-driven parameterization of an acoustic emission-based process monitoring for the milling of CFRP.


2020 ◽  
Vol 2 (2) ◽  
pp. 232-250
Author(s):  
Maxime Gaborit

Abstract Since 2018, climate mobilizations have been shaping political life in Europe. Young people are at the heart of this mobilization, both because of their massive nationwide presence in intergenerational demonstrations, but also because of their own modes of action, such as the climate strikes that have been emerging since January 2019. Within these mobilizations, forms of radicalism are expressed through an important support for civil disobedience, such as blocking actions, as well as support – for a significant part of protestors – for material damage. This paper analyzes the new forms of youth radicalism in their link to the social determinations of the awareness of the climate catastrophe. Based on a demonstration survey concerning three French cities for the strike of March 15, 2019, and in Paris for the strike of September 20th, which collected more than 1,800 questionnaires, this paper sets out to show the sociological profiles of radical individuals, which distinguish themselves by significant cultural capital and left-wing familial political socialization. The exploitation of the data collected shows that these new forms of radicalism are conditioned by an awareness of the climate emergency, deeply linked to family legacies and specific academic curricula. The radicalization of inherited dispositions leads these individuals to go beyond the legality/illegality framework, and to favor a debate on the effectiveness of the means of action, in which the link with conventional democratic participation is constantly questioned.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xuecai Xu ◽  
Željko Šarić

This study intended to investigate the interactions between accident severity levels and traffic signs in state roads located in Croatia and explore the correlation between accident severity levels and heterogeneity attributed to unobserved factors. The data from 460 state roads between 2012 and 2016 were collected from Traffic Accident Database System maintained by the Republic of Croatia Ministry of the Interior. To address the correlation and heterogeneity, Bayesian bivariate Tobit quantile regression models were proposed, in which the bivariate framework addressed the correlation of residuals with Bayesian approach, while the Tobit quantile regression model accommodated the heterogeneity due to unobserved factors. By comparing the Bayesian bivariate Tobit quantile and mean regression models, the proposed quantile models showed priority to mean model. Results revealed that (1) low visibility and the number of invalid traffic signs per km increased the accident rate of material damage, death, or injury; (2) average speed limit exhibited a close relation with accident rate; and (3) the number of mandatory signs was more likely to reduce the accident rate of material damage, while the number of warning signs was significant for accident rate of death or injury.


Author(s):  
Tairui Zhang ◽  
Weiqiang Wang ◽  
Aiju Li

In this study, we investigated the drawbacks of previous studies regarding the evaluation of fracture toughness from spherical indentation tests (SITs). This was achieved by an examination of the material damage mechanism during indentation tests, uniaxial tensile tests, and Mode I/II fracture tests. A new approach based on the energy release rate was proposed in this study to evaluate the fracture toughness of ductile metals. Scanning electron microscope (SEM) observations revealed that the mechanism for material damage during an indentation test was different with the material damage in uniaxial tensile tests and Mode I fracture tests, but similar to that in Mode II fracture tests. Thus, the energy release rate during SITs should be correlated with JIIC. Compared with previous studies, this new proposed method was more consistent with the actual damage mechanism and did not rely on the specific critical damage values. Experiments on SA508, SA533, 15CrMoR, and S30408 revealed that the maximum error from this energy release rate-based approach was no more than 13% when compared with their conventional counterparts (compact tension tests), and thus can meet the precision requirement of engineering applications.


2020 ◽  
Vol 11 (5) ◽  
pp. 221
Author(s):  
Gulnara A. Gareeva ◽  
Diana R. Grigoreva ◽  
Ilnur I. Mahmutov

One of the main factors of the effectiveness of the enterprise is the staff. Competent accounting and analysis of calculations with staff for other operations can significantly affect the final financial activities of any organization. The calculations with the staff are not a less important component of the final report of the organization, on the basis of which the profit is formed. All this leads to whether the company conducts effective financial activity or not. The organization's calculations with employees for other operations include payments for merchandise paid by it to merchants, for goods purchased by employees with payment by installments at the expense of the credit received by the organization in the bank, on loans issued to employees. It also involves payments for individual housing construction, the purchase or construction of garden houses, the acquisition of a household. The main aim is to recover material damage caused by an employee of the organization as a result of shortages and theft of monetary and material values and other types of damage. To achieve this goal, the following tasks were solved: the theoretical basis for accounting for loans granted, for material damage compensation was considered, the company was analyzed. In this paper, we consider the main aspects of the management of personnel by other operations, their competent accounting, as well as analysis based on the average statistical data of companies in Russia (Gareeva & Grigoreva, 2019).


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