Base shear coefficient

The base shear coefficient normalized with respect to the total weight ofthe building is shown in Figure 7, comparing the uncontrolled and the controlled structure. An average reduction of the base shear is observed for all the earthquake records of about 26%, while the higher reduction is obtained with Hachinobe earthquake (47%). 

For an SP system with friction coefficient of 0.06 and a peak base shear coefficient of 0.25, the equivalent damping can easily computed as... 

The base shear coefficient y is dehned as the base shear Vy at onset of yielding divided by the total weight W. 

Steel Posttensioned Connections with Web Hourglass Pins Toward Earthquake Resilient Steel Structures, Fig. 27 Base shear coefficient - roof drift behavior from nonlinear monotraiic (piushover) static analysis... 

Figure 27 shows the base shear coefficient (WHO - roof drift (0 ) behavior of the conventional MRF and the SC-MRF from nonlinear monotonic (pushover) static analysis. V is the base shear and W is the seismic weight. An inverted triangular force distribution along with roof displacement control was used in these analyses. The MRF and the SC-MRF have comparable base shear strengths and comparable... 

Davis et al. [42] have recently introduced the terms rotator and extender for a variety of ferroelectrics based on oxygen octahedra, in order to classify them with respect to whether the shear or the collinear effect dominates in the piezoelectric response. In extenders, the dominant polarization extension is directly related to the collinear piezoelectric effect, whereas in rotators the dominant contribution to the piezoelectric effect is the polarization rotation, that is directly related to the shear piezoelectric effect. Thus, extenders are ferroelectrics with a large longitudinal piezoelectric coefficient 33 that is related to a large relative dielectric susceptibihty %33, while rotators are ferroelectrics with large shear coefficients dis and 24. which are related to transverse susceptibilities and %2z. correspondingly. Electrostrictive... 

In the context of force-based seismic design, the design behavior factor q is a design force reduction coefficient greater than 1.0 by which the EDRS-specified base shear of the struc-... 

Traditionally, the seismic design of buildings is based on computing a solicitation for the structure in terms of a base shear force through the consideration of a seismic coefficient or spectrum, which is reduced by a behavior factor and distributed after to the structure. However, the behavior factor values recommended in Eurocode 8 (EN 1998-1 2004) for masoiuy structures (1.5-2.0) turned out to be very conservative, and often the buildings are considered unsafe. In this case, the consideration of an overstrength... 

ASCE/AWEA RP2011 suggests Equations 15.4-1 and 15.4-2 of ASCE/SEI 7-05 for the seismic response coefficient Cs (nonbuDding structures), if Equatirai 12.8-1 of ASCE/SEI 7-05 is used to compute the seismic base shear. SpecificaUy, in Eq. 15.4-2 of ASCE/SEI 7-05 for Cs a response modification factor R = 1.5 is recommended by ASCE/AWEA RP2011. The use of R = 1.5 does not necessarily imply that a ductile response or material overstrength is expected but accounts for a certain conservatism in the seismic response coefficient Cs prescribed for nonbuilding structures. 

In regard to screw threads, certain observations should be considered. First, the torque values are based on the coefficients of friction of the mating parts and can thus vary significantly. The use of any compatible lubricant that reduces friction will increase the shear and hoop stresses if the torque remains the same. Therefore, with lubricants, reduce the amount of allowable torque. 

While the theoretical value (based on homogeneous, isotropic turbulence) of the Smagorinsky coefficient cs amounts to 0.165 (Mason and Callen, 1986), in many simulation studies lower values for cs proved to result in a better reproduction of experimental data. This may have to do with the abundant presence of shear flows in process equipment. Derksen (2003) reported that varying cs values in the range 0.08-0.14 does not have a large impact on the simulation results. A value of 0.12 is recommended. 

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