نتایج جستجو برای: equivalent damping

تعداد نتایج: 160142  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ولی عصر (عج) - رفسنجان - دانشکده ادبیات و علوم انسانی 1393

the present study investigated construct equivalence of multiple choice (mc) and constructed response (cr) item types across stem and content equivalent mc and cr items (item type ‘a’), non-stem-equivalent but content equivalent mc and cr items (item type ‘b’), and non-stem and non-content equivalent mc and cr items (item type ‘c’). one hundred seventy english-major undergraduates completed mc ...

Journal: :Journal of dentistry 2006
Haw-Ming Huang Chi-Yang Tsai Hao-Fu Lee Che-Tong Lin Wei-Cheng Yao Wen-Ta Chiu Sheng-Yang Lee

OBJECTIVES The aim of this study was to evaluate the effects of damping on stress concentration in an impacted incisor. METHODS Damping ratios of maxillary incisors were tested using an in vivo modal testing method. A finite element model of the upper central incisor was established for dental trauma analysis. To assess the effect of damping properties on induced stresses in the traumatized i...

Journal: :international journal of civil engineering 0
m. biglari civil engineering department, school of engineering, razi university, kermanshah, iran, p. o. box: 67149-67346 i. ashayeri civil engineering department, school of engineering, razi university, kermanshah, iran, p. o. box: 67149-67346

seismic ground motion is profoundly affected by geometrical and mechanical properties of soil deposits overlaying bedrock. local seismic ground response of saturated soil deposits was studied in literature by applying the effects of soil stress state and index properties on the strain-dependent normalized shear modulus reduction, g/g0, and damping ratio, d, curves in an equivalent linear analys...

2002
W H Liao

Semi-active control systems are becoming more popular because they offer both the reliability of passive systems and the versatility of active control systems without imposing heavy power demands. In particular, it has been found that magnetorheological (MR) fluids can be designed to be very effective vibration control actuators, which use MR fluids to produce controllable damping force. The ob...

2008
Babak Moaveni Andre R. Barbosa Marios Panagiotou Joel P. Conte Jose I. Restrepo

Obtaining accurate estimates of damping parameters from experimental measurements of structures has been a challenge in the civil engineering community. In general, the confidence level on the identified damping is much lower than that of the identified natural frequencies and mode shape components. Most system identification methods are based on linear system and control theories, while in rea...

2012
Liang Dong Roderic S Lakes

Negative stiffness is understood as the occurrence of a force in the same direction as the imposed deformation. Structures and composites with negative stiffness elements enable a large amplification in damping. It is shown in this work, using an experimental approach, that when a flexible flat-ends column is aligned in a post-buckled condition, a negative structural stiffness and large hystere...

2009
Q. - H. Nguyen F. Legeron T. - P. Le

The dynamic wind loads are considered in terms of equivalent static wind load based on gusteffect factor in most of the current design practices. In ASCE 7-05, the equivalent static wind load is based on the gust-effect factor f G which corresponds with the displacement at the highest point of the structure for flexible or dynamically sensitive structures. Gust-effect factors are calculated dir...

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