in the aftermath of the 1994 northridge, california, earthquake. a significant number of steel moment resisting structural systems were damaged. many studies and researches have been conducted to improve the seismic performance of structures after the catastrophe. one of the proposed connections for special moment-resisting frames included aisc-358 is kaiser bolted bracket moment connection, br...

Endurance time (ET) method is a relatively new performance-based earthquake method for structural evaluation and design. In this method, the structure is subjected to a gradually intensifying accelorogram(s) and its performance is assessed based on the maximum time duration that it can meet the specified performance objectives. Using moment-resisting and braced frames which are rehabilitated by...

The experience of past prominent earthquakes establishes the fact that the structure’s catastrophes and casualties can be dramatically decreased through the use of self-centering systems. A promising post-tensioned self-centering yielding braced system (PT-SCYBS) has been developed, comprising of two main components, including the post-tensioned wires, exhibiting the desirable self-centering pr...

Modular structural systems are constructed using a method that they are assembled with prefabricated unit modular frames on-site. This provides a benefit that can significantly reduce building construction time. The structural design is usually carried out under the assumption that their load-carrying mechanism is similar to that of traditional steel moment-resisting systems. However, both syst...

The objective of the current study is to develop a simple formula to estimate the fundamental vibration period of tall buildings for using in equivalent lateral force analysis specified in building codes. The method based on Sturm-Liouville differential equation is presented here for estimating the fundamental period of natural vibration. The resulting equation, based on the continuum represent...

BACKGROUND Despite several studies with different methods, the effect of functional knee braces on knee joint kinematics is not clear. Direct visualization of joint components through medical imaging modalities may provide the clinicians with more useful information. OBJECTIVES In this study, for the first time in the literature, video fluoroscopy was used to investigate the effect of knee br...

braced frames structures have a good lateral stiffness against earthquakes. however, energy loss of their members is slight and strong forces are given to the structures. moment frames have a more flexible function against earthquakes and also have a better flexibility than braced frames. however, since its lateral stiffness is low, too much displacement of the structure results in an increase ...

Reinforced concrete frame buildings with Open Ground Story (OGS) are one of the most common building configurations in urban habitat. These configurations are known to be vulnerable to seismic excitations, primarily due to the sudden loss in strength in the ground story and differential stiffness distribution throughout the structure. The differential stiffness distribution is attributed primar...