Stiffness Modifications for Vibration Solutions of Multistory Frames (An Approach from Buckling to Vibration)

International Journal of Civil Engineering

© 2019 by SSRG - IJCE Journal

Volume 6 Issue 1

Year of Publication : 2019

Authors : NwoforT.C. and Obianime, Tamunoene Sunday

10.14445/23488352/IJCE-V6I1P105

How to Cite?

NwoforT.C. and Obianime, Tamunoene Sunday, "Stiffness Modifications for Vibration Solutions of Multistory Frames (An Approach from Buckling to Vibration)," SSRG International Journal of Civil Engineering, vol. 6,  no. 1, pp. 25-36, 2019. Crossref, https://doi.org/10.14445/23488352/IJCE-V6I1P105

Abstract:

Vibration analysis has been approached through a common knowledge of buckling in this study. The introduction of the effective vibration length in vibration analysis makes vibration solutions very easy and design-oriented - effortlessly computing the frames' frequencies. Modification of Stiffness introduced to the concept of effective vibration length has enabled its application to every type of frame (rigid or flexible). The study shows the convergence of results by the present method to results by other reliable sources (error ranging from 0 – 2.5%). It has been observed that in multi-story steel frames, the average percentage difference between the present manual method and computer-based analysis increases as the height of the buildings increases. Hence this new method needs to be investigated further to improve results where the error should be less than one percent. Areas of improvement suggested are developing a mathematical model of the column alignment chart and taking the average of all the joint stiffness coefficients in a parent multi-story frame as the top stiffness coefficient determining the effective length of the reduced frame. However, taking the reduced frame stiffness coefficient as that of any joint with the highest coefficient has yielded results that are very close to results by computer-based dynamic analysis and other very reliable sources. Effective vibration length offers a new and easier way of providing vibration solutions.

Keywords:

Vibration Solution, Buckling, Stiffness

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