Dynamic analysis methodology for progressive failure of truss structures considering inelastic postbuckling cyclic member behavior

The work is devoted to the urgent problem of the danger of the growth of extremist sentiments among young people caused by unpredictable changes in ideological attitudes (attitudes) in the group consciousness. Objectives: study of the dynamics of peripheral ideological concepts – one of the structural elements of ideology; identifying the trend of changes in the ideological attitudes of student youth on the example of the South of Russia; assessment of the predictive capabilities of the system dynamic analysis methodology for calculating the dynamics of ideological processes. An attempt was made to approbate the author's method of studying ideological attitudes, which could be conditionally called quantitative narrative analysis. The empirical base was made up of data from a survey of 2500 students in the South of Russia and the results of a five-year monitoring of the development of the ideological situation. The theoretical basis is the morphological approach to the study of ideologies by Michael Frieden and the concept of the cognitive-ideological matrix. In the development of this concept, the focus of the study was shifted from the morphology (structure) of ideologies to implicit processes occurring at the border of the cognitiveideological matrix and the social environment. As a result, a descriptive mental model of peripheral ideological concepts and a conceptual model of their migration based on the Bass diffusion model were built, performed in the AnyLogic simulation system. The result of the study was the identification of a left-liberal trend using narrative analysis, which had replaced the significant predominance of conservative and national-patriotic ideological attitudes in the group youth consciousness. It is concluded that the model of migration of peripheral ideological concepts, created using the method of system dynamics and mathematical statistics, significantly expands the possibilities of forecasting ideological processes, but has some limitations.

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Comparison of Responses of Guyed and Freestanding Transmission Line Towers Under Conductor Breakage Loading

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455415400234 ◽

2015 ◽

Vol 15 (08) ◽

pp. 1540023 ◽

Cited By ~ 4

Author(s):

Fábio Alminhana ◽

Faris Albermani ◽

Matthew Mason

Keyword(s):

Dynamic Analysis ◽

Transmission Line ◽

Progressive Failure ◽

Time History ◽

Structural System ◽

Structural Components ◽

Analysis Scheme ◽

Internal Forces ◽

Nonlinear Time History ◽

Explicit Dynamic

Cascades have been a prominent feature of many transmission line (TL) accidents around the world. During these events, a localized member failure changes the boundary conditions of the structural system, magnifying member loads over a considerable extension of the line. This results in the progressive failure of successive support structures. Phase conductor breakage is regarded as the most severe cascade triggering event, generating a shock wave that propagates through the conductor and induces large unbalanced longitudinal loads on the transmission line components. Under such an extreme loading event, nonlinear time-history dynamic analysis has to be employed to predict the response of the TL system. In the present work, an explicit dynamic analysis scheme is developed to predict the response of a multi-span TL section. The analysis includes all the main structural components of a TL section. This procedure was used to investigate the response of two types of suspension steel latticed towers, guyed and freestanding, subjected to conductor breakage loading. Results indicate the occurrence of peak dynamic loads (PDLs), that significantly increase the internal forces in system components, exceeding their design capacities, particularly in tower's members. The results also show that the guyed tower accommodates such a loading event more adequately than the freestanding tower.

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