دانلود رایگان مقاله انگلیسی پیشرفت هایی در آنالیز قاب خمشی درونی - اشپرینگر 2017

Abstract

The paper introduces a number of new analytic techniques and practical technologies that lead to the development of an efficient earthquake resistant system. The proposed structural system consists of a grade beam supported moment frame connected to a rigid rocking core through story level rigid links. The new system tends to bend and tilt as an upright simply supported beam with minimal uniform drift and prevents the formation of soft story failure within the moment frame. It is capable of preventing severe damage to its columns and footings and can be equipped to prevent catastrophic collapse due to strong ground motion and re-center itself afterwards. The analytic development is based on global, design led analysis and results in closed form, exact solutions that are highly suitable for preliminary, manual, as well as spread sheet computations. Several examples have been provided to verify and demonstrate the applications of the proposed formulations. All numerical results have been verified by independent computer analysis.

8 Conclusions

A new earthquake resisting structural system incorporating post tensioned RRCs and MFs has been presented. Vertical and horizontal stressed tendons, gap opening devices as well as BRBs have been provided to ensure collapse prevention and active re-centering. Both Horizontal and vertical post-tensioned devices produce resisting moments to service loading along the frame and provide restoring forces that tend to return the damaged MF and the RRC to their pre-earthquake position. The paper also provides a basis for developing sustainable earthquake resisting structures in the future.

Global Design Led analysis which is a new analytic approach has been used to develop exact, closed form solutions for RCMFs under gravity and lateral loading conditions. The proposed mathematical model is ideally suited for manual preliminary design of such systems. The proposed configuration is both construction friendly and satisfies the theoretical conditions of minimum weight design. Several examples have been provided to verify and demonstrate the applications of the proposed formulations. Two new gap opening link mechanisms, one for steel and the other for concrete structures that do not induce unwanted moments in the columns have also been introduced.