A Generalized Newmark Method for the assessment of permanent displacements of flexible retaining structures under seismic loading conditions

2019 ◽  
Vol 117 ◽  
pp. 221-233 ◽  
Author(s):  
Elisabetta Cattoni ◽  
Diana Salciarini ◽  
Claudio Tamagnini
DYNA ◽  
2017 ◽  
Vol 84 (202) ◽  
pp. 9-15
Author(s):  
André Luís Brasil Cavalcante ◽  
Juan Félix Rodríguez Rebolledo

En este artículo se describe una metodología basada en el método de estimación puntual de Rosenblueth para el análisis del empuje activo desarrollado en un muro de retención con relleno cohesivo-friccionante bajo condiciones de carga sísmica. El principio básico de esta metodología es usar dos estimaciones puntales, i.e., la desviación estándar y el valor medio, para examinar una variable en el análisis de seguridad. Es posible mostrar que aumentando el valor del coeficiente de aceleración sísmica horizontal, el factor de seguridad por volteo decrece y la probabilidad de falla aumenta, especialmente para coeficientes mayores que 0.2. Por otro lado, es observado que el valor medio del factor de seguridad crece cuando aumenta el coeficiente de aceleración sísmica vertical, sin embargo la probabilidad de falla se mantiene prácticamente igual para el valor del factor de seguridad considerado como crítico (1.15).


2012 ◽  
Vol 135 (1) ◽  
Author(s):  
George E. Varelis ◽  
Spyros A. Karamanos ◽  
Arnold M. Gresnigt

Motivated by the response of industrial piping under seismic loading conditions, the present study examines the behavior of steel process piping elbows, subjected to strong cyclic loading conditions. A set of experiments is conducted on elbow specimens subjected to constant amplitude in-plane cyclic bending, resulting into failure in the low-cycle-fatigue range. The experimental results are used to develop a low-cycle-fatigue curve within the strain-based fatigue design framework. The experimental work is supported by finite element analyses, which account for geometrical and material nonlinearities. Using advanced plasticity models to describe the behavior of elbow material, the analysis focuses on localized deformations at the critical positions where cracking occurs. Finally, the relevant provisions of design codes (ASME B31.3 and EN 13480) for elbow design are discussed and assessed, with respect to the experimental and numerical findings.


Author(s):  
Jin Weon Kim ◽  
Myung Rak Choi ◽  
Sang Bong Lee ◽  
Yun Jae Kim

This study investigated the loading rate effect on the fracture resistance under cyclic loading conditions to clearly understand the fracture behavior of piping materials under excessive seismic conditions. J-R fracture toughness tests were conducted under monotonic and cyclic loading conditions at various displacement rates at room temperature (RT) and the operating temperature of nuclear power plants (NPPs), i.e., 316°C. SA508 Gr. 1a lo w-alloy steel (LAS) and SA312 TP316 stainless steel (SS) piping materials were used for the tests. The fracture resistance under a reversible cyclic load was considerably lower than that under monotonic load regardless of test temperature, material, and loading rate. Under both cyclic and monotonic loading conditions, the fracture behavior of SA312 TP316 SS was independent of the loading rate at both RT and 316°C. For SA508 Gr. 1a LAS, the loading rate effect on the fracture behavior was appreciable at 316°C under both cyclic and monotonic loading conditions. However, the loading rate effect diminished when the cyclic load ratio (R) was −1. Thus, it was recognized that the fracture behavior of piping materials, including seismic loading characteristics, can be evaluated when tested under a cyclic load of R = −1 at a quasi-static loading rate.


1990 ◽  
Vol 35 (1-3) ◽  
pp. 565-571 ◽  
Author(s):  
E. Brühwiler ◽  
F.H. Wittmann

2018 ◽  
Vol 13 (48) ◽  
pp. 884-893
Author(s):  
Tarek Bahr ◽  
M A ◽  
H Hassan ◽  
A A ◽  
A M ◽  
...  

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