چكيده به لاتين
The Innovative hybrid coupled shear wall system (Inn-HCW) is one of the most advanced economical structural systems which has already been conducted. It constitutes of RC shear wall connected to two side steel columns by mean of replaceable coupling steel links. The main design objective of this system is to withstand lateral loads with minimized or even no damage of non-replaceable components (i.e. RC wall and steel columns), while the replaceable coupling steel links could undergo severe damage. This system still highly lacks investigations and detailed estimation as well as being of low efficiency in low-rise buildings. In the first part of this research, the emphasis is upon the estimation of the most efficient current Inn-HCW systems which have been recommended in literature so far, to be thoroughly calibrated against equivalent conventional RC wall system. Furthermore, new recommendations are presented in intention of optimizing the performance of Inn-HCW system to efficiently achieve the design objective through eleven multi-type modifications: links arrangement, internal wall structure and combined systems. The study implements an advanced modelling procedure and nonlinear dynamic analyses with fragility assessment to obtain a highly reliable evaluation. A new finite element model was also proposed for shear critical composite link using Opensees platform. The newly proposed methods reveal excellent efficiency, especially in low-rise buildings.
In the second part, the objective is to facilitate the design process of innovative steel and concrete hybrid coupled wall system. To this end, a group of 120 innovative hybrid coupled wall systems subjected to a set of 100 far-field ground motions are selected. 420,000 of nonlinear dynamic time histories on the basis of incremental dynamic analysis (IDA) are carried out in order to generate a databank of specified response quantities. Subsequently, nonlinear regression analyses are conducted for both designed and undesigned structures in order to derive simple formulae which offer a direct estimation of: fundamental periods of vibration, yield displacements, lateral displacements at steel first yielding in inner wall, lateral displacements with respect to a predefined IDR,max and IDR1,max (maximum first storey drift); ductility demands for a target IDR,max, IDR1,max , and maximum rotation in links; maximum links’ rotations along the building height, residual drift, and relative distribution of storey shear for a target ductility; behaviour factor q associated with steel first yielding of internal wall, and behaviour factor q relation as being a function of roof ductility μr. Moreover, damage limit states of the inner concrete wall are also formulated.
The effect of the following parameters: number of storeys, coupling ratio, steel area ratio of boundary elements, uniformity status of shear links, and length of links is thoroughly investigated. The results indicate that storeys number and uniformity status parameters have the largest influence on most of response quantities. The current q behaviour factor value is approximately suitable for low-rise buildings, but it is highly underestimated in medium and high rise buildings. Furthermore, the equal-displacement rule of Eurocode8 clearly overestimates the roof ductility. The new proposed q-μr relation indicates better suitability than the Eurocode8 rule.
An economical estimation of Inn-HCW system in comparison with the recent advanced hybrid coupled wall system is also carried out. The results indicate that the Inn-HCW system shows better economic gains. After all, a new hybrid force/displacement performance-based design method for Inn-HCW system is proposed and estimated against the current design method. The results reveal that the proposed design method seems to be more efficient and economic than the current one. This efficiency and economic ability dramatically raises when building height increases.
Overall, this study bridges all the gaps about the innovative hybrid coupled wall system methodology and provides the designers with substantial guidelines which are considered as a great contribution to promote the diffusion of this structural solution.
