Indirect evaluation method for frame-core tube structure outer frame rigidity contribution

Abstract

The invention provides an indirect evaluation method for a frame core tube structure outer frame rigidity contribution. The method comprises the following steps: carrying out modal analysis on a modelof the frame core tube structure; obtaining a first-order translation period and a second-order translation period when the model vibrates along a set translation direction, and dividing the second-order translation period of the model by the first-order translation period of the model to obtain a second-order translation period ratio of the model; deleting an outer frame in the model, and carrying out modal analysis on the core tube; obtaining a first-order translation period and a second-order translation period when the core tube vibrates along a set translation direction, and dividing thesecond-order translation period of the core tube by the first-order translation period of the core tube to obtain a second-order translation period ratio; subtracting the second-order translation period ratio of the core tube from the second-order translation period ratio of the model to obtain a second-order translation period ratio increment; and according to the size of the second-order translation period ratio increment, performing grading evaluation on the rigidity contribution of the outer frame. The method is reliable in evaluation result and can provide theoretical support for anti-seismic design of the frame core tube structure.

Description

technical field [0001] The invention relates to the technical field of anti-seismic design of a frame-core tube structure, in particular to an indirect evaluation method for the stiffness contribution of an outer frame of a frame-core tube structure. Background technique [0002] The frame-core tube structure system is the most commonly used double lateral force-resistant structure for high-rise buildings. The system consists of two systems, the frame and the core tube, and they work together to resist external forces. In order to ensure multiple lines of defense under major earthquakes, the seismic codes of many countries have made quantitative regulations on the shear force borne by the frame part. The United States "Internationalbuilding Code 2000" proposes that in a frame-core tube (frame-shear wall) structure, under earthquake action, when the design story shear force of the frame part is not less than 25% of the total shear force of the side force system. my country'...

AI Technical Summary

Problems solved by technology

However, in the actual design, most super high-rise frame-core tube structures are difficult to meet this requirement. In many projects, the seismic shear force borne by the frame is only 4%-5% of the total structural shear force, which is far from the code requirements, but In order to meet the requirements of the code, the section size of the member must be continuously increased, which not only makes the design unreasonable, but also pays a large economic cost

[0003]In fact, the proportion of shear force sharing cannot always reasonably reflect the ability of the second line of defense of the outer frame, nor is it a very effective index to reflect the contribution of outer frame stiffness. The proportion often misjudgments the contribution of the outer frame stiffness

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