结构周期的调整方法（Method for adjusting structural period）.doc

结构周期的调整方法（Method for adjusting structural period） Reverse cycle occurs in fifth formation need to adjust? What explains, can reverse the cycle occurs in the first cycle, if occurred in the first period and the second period how to adjust? Answer: the torsional stiffness is large from the result, torsion can weaken some cost on the economy may be, that is to say there is possible in the fifth formation, is not the economy, is to adjust the specific structure of each optimization problem, rather than the structural safety problem. Personally think that the reverse cycle occurs in which mode is possible, or is the translational torsional, lateral stiffness and torsion is the embodiment of stiffness ratio, torsional period is in the front that the torsional rigidity of the larger structure more insecure, members more easily because of torsion failure, because the vertical component under torque the total time, the vertical component of the farther away from the heart of the structural stiffness will bear greater shear component, shear failure is brittle, and the structure design of the combination of internal force small earthquakes based on reinforcement, moderate and strong earthquakes by structural measures to achieve, such as strong column and weak beam, strong shear weak bending, shear torque is generated in the structure in the earthquake and large earthquake under will obviously increase the components of the structure, resulting in vertical wall column component to resist horizontal shear force, which leads to brittle shear failure, The overall structure and even lead to collapse when the first formation is time to reverse cycle, reverse the longest time, the most likely to reverse the damage, very dangerous. Attached: The first or the second mode of adjustment method under torsion 1) mode in the SATWE program are sorted in the cycle length. 2), the first second modes of the structure should be the translational and torsional period should appear in the third mo