scholarly journals EVALUATION OF SEISMIC DESIGN STRENGTH REDUCTION FACTOR CONSIDERING CUMULATIVE DAMAGE AND SITE CONDITIONS

2006 ◽  
Vol 71 (607) ◽  
pp. 73-80
Author(s):  
Philip DE GUZMAN ◽  
Mitsumasa MIDORIKAWA ◽  
Tetsuhiro ASARI ◽  
Yuji ISHIYAMA
Keyword(s):  
Seismic Design ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Cumulative Damage ◽  
Site Conditions ◽  
Strength Reduction Factor ◽  
Design Strength

Studies on Seismic Demand Spectra Based on Strength Reduction Factor

2011 ◽  
Vol 243-249 ◽  
pp. 4047-4051
Author(s):  
Xiao Li Zhu ◽  
Gao Hang Cui ◽  
Xia Xin Tao
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Structural Characteristics ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Seismic Demand ◽  
Capacity Design ◽  
Strength Reduction Factor ◽  
Seismic Design Code ◽  
Bridge Structures

For resolving the practical problem about bridge structures, according to the seismic damage regularity and the structural characteristics, the capacity design method of bridge structure was introduced. In order to account synthetically for the influence factors and convert the inelastic seismic design method into the pseudo-static method, which is easily accepted by engineers, the strength reduction factor was commonly used in seismic design of structures. Based on the principles of the inelastic spectrum established by using the relationship between the strength reduction factor R and ductility factor μ, the seismic demand spectra were obtained from the design spectrum of the Highway Engineering Seismic Design Code (JTJ 004-89). This will be beneficial to the earthquake-resistant capacity design in practical bridge structures.

Drift and Ductility Estimates in Regular Steel MRF Subjected to Ordinary Ground Motions: A Design-Oriented Approach

2008 ◽  
Vol 24 (2) ◽  
pp. 431-451 ◽  
Author(s):  
Theodore L. Karavasilis ◽  
Nikitas Bazeos ◽  
Dimitri E. Beskos
Keyword(s):  
Seismic Design ◽  
Simple Procedure ◽  
Ground Motions ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Time History ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Strength Reduction Factor ◽  
Existing Structures

A simple procedure to estimate drift and ductility demands of regular steel frame buildings subjected to ordinary (i.e., without near fault effects) ground motions is described. Given the strength reduction (or behavior) factor, the procedure provides reliable estimates of the maximum roof displacement, the maximum interstorey drift ratio and the maximum rotation ductility along the height of the structure. The strength reduction factor refers to the point of the development of the first plastic hinge in the building and thus, pushover analysis and estimation of the overstrength factor are not required. This important feature enables both the rapid seismic assessment of existing structures and the direct deformation-controlled seismic design of new ones. The derivation of the proposed relations is based on regression analysis of the results of thousands of nonlinear time history analyses of steel frames. A comparison of the proposed method with the procedures adopted in current seismic design codes reveals the efficiency of the former.

Influence of Wear Properties on Fretting Fatigue Life of a CK45 Alloy and the Al7175 Alloy

2008 ◽  
Vol 587-588 ◽  
pp. 971-975 ◽  
Author(s):  
M. Buciumeanu ◽  
A.S. Miranda ◽  
F.S. Silva
Keyword(s):  
Wear Resistance ◽  
Fatigue Life ◽  
Material Properties ◽  
Fatigue Behavior ◽  
Synergetic Effect ◽  
Fretting Fatigue ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Strength Reduction Factor ◽  
Wear Properties

The main objective of this work was to study the influence of the wear properties of two commercial alloys (CK45 and Al7175) on their fretting fatigue behavior. It is verified the effect of material local degradation by wear on a fatigue strength reduction factor, namely the stress concentration factor, and on the overall fretting fatigue life of these materials. The fretting fatigue phenomenon is a synergetic effect between wear and fatigue. It is dependent on both the fatigue and the wear properties of the materials. Material properties promoting an increase in wear resistance should enhance fretting fatigue life.

Design of Pressure Vessels for Low-Cycle Fatigue

1962 ◽  
Vol 84 (3) ◽  
pp. 389-399 ◽  
Author(s):  
B. F. Langer
Keyword(s):  
Fatigue Strength ◽  
Pressure Vessel ◽  
Low Cycle Fatigue ◽  
Fatigue Curve ◽  
Pressure Vessels ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Strength Reduction Factor ◽  
The Mean ◽  
Fatigue Evaluation

Methods are described for constructing a fatigue curve based on strain-fatigue data for use in pressure vessel design. When this curve is used, the same fatigue strength-reduction factor should be used for low-cycle as for high-cycle conditions. When evaluating the effects of combined mean and alternating stress, the fatigue strength-reduction factor should be applied to both the mean and the alternating component, but then account must be taken of the reduction in mean stress which can be produced by yielding. The complete fatigue evaluation of a pressure vessel can be a major task for the designer, but it can be omitted, or at least drastically reduced, if certain requirements can be met regarding design details, inspection, and magnitude of transients. Although the emphasis in this paper is on pressure vessel design, the same principles could be applied to any structure made of ductile metal and subjected to limited numbers of load cycles.

Strength reduction factor of self-centering structures under near-fault pulse-like ground motions

2020 ◽  
Vol 24 (1) ◽  
pp. 119-133
Author(s):  
Huihui Dong ◽  
Qiang Han ◽  
Xiuli Du ◽  
Canxing Qiu
Keyword(s):  
Ground Motions ◽  
Time History ◽  
Reduction Factor ◽  
Strength Reduction ◽  
The Self ◽  
Hysteretic Behavior ◽  
Hysteretic Model ◽  
Strength Reduction Factor ◽  
Vibration Period ◽  
Near Fault

Many studies on the strength reduction factor mainly focused on structures with the conventional hysteretic models. However, for the self-centering structure with the typical flag-shaped hysteretic behavior, the corresponding study is limited. The main purpose of this study is to investigate the strength reduction factor of the self-centering structure with flag-shaped hysteretic behavior subjected to near-fault pulse-like ground motions by the time history analysis. For this purpose, the smooth flag-shaped model based on Bouc-Wen model which can show flag-shaped hysteretic behavior is first described. The strength reduction factor spectra of the flag-shaped model are then calculated under 85 near-fault pulse-like ground motions. The influences of the ductility level, vibration period, site condition, hysteretic parameter, and hysteretic model are investigated statistically. For comparison, the strength reduction factors under ordinary ground motions are also analyzed. The results show that the strength reduction factor from near-fault pulse-like ground motions is smaller. Finally, a predictive model is proposed to estimate the strength reduction factor for the self-centering structure with the flag-shaped model under near-fault pulse-like ground motions.

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