Full-Scale Experimental Modeling to Study Wind-Induced Vibrations, Wind Driven Rain and their Effects on Curtainwall Window Systems

Authors

Krishna Sai VutukuruFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Civil Engineering

First Advisor's Name

Arindam Gan Chowdhury

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Peter Irwin

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Ioannis Zisis

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Seung Jae Lee

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

NIpesh Pradhananga

Fifth Advisor's Committee Title

Committee member

Keywords

Operable Window, Dynamic Effects, Vibration damage, Components and Cladding, Rain Intrusion, Rain Size Distribution, Wind Induced Vibration, Wind damage

Date of Defense

11-5-2021

Abstract

Lewis Fry Richardson famously summarized turbulence as big whirls have little whirls, that feed on their velocity and little whirls have lesser whirls, and so on to viscosity. Big whirls/eddies typically affect the whole building structure whereas small eddies cause local area pressures causing damage to building components. Oncoming wind may carry high energy content due to these small eddies in the high-frequency range and sometimes these frequencies fall in the range of natural frequency of building components. These small eddies may cause response amplification due to this resonance, which is currently not considered in design codes such as ASCE 7-16. This dissertation, through full-scale experimental testing, addressed the possible resonance due to the matching of frequencies of an operable window with oncoming wind.

Curtainwalls have become a part of modern infrastructure especially to preserve architectural freedom. Operable windows are usually attached to these glazing units for ventilation. However, in high-rise buildings and/or extreme wind events these window frames are susceptible to vibrations. To evaluate wind-induced stresses, code guidelines focus on simplified uniform pressure-based static/cyclic load test procedures. These do not address the realistic dynamic wind loading which failed several engineered curtain-wall window systems due to vibrations, such as the 2020 Hurricane Laura damage to the Capital One building in Louisiana. To address this knowledge deficit and provide the curtain wall industry with realistic dynamic test data, full-scale curtain wall units with operable windows are tested in the Wall of Wind Facility.

These local vibration failures also lead to water intrusion into buildings causing interior content damage. To quantify and detect the vulnerable window system components a full-scale Rain Size Distribution (RSD) is developed at the Wall of Wind facility with the help of 3-D printed nozzles. The window sample is exposed to horizontal wind-driven rain and the results are quantified as rain rate entering through the window area. These results helped to understand the risks inherent in current window design by exposing weak locations under extreme wind loading and showed the inadequacy of code guidelines for wind-driven rain testing. The current study provided Dynamic Amplification Factor values that can be incorporated into the current quasi-static design approach to include dynamic effects. The results from this study would be utilized to develop and validate a dynamic finite element model and disseminated to the curtain wall industry.

Identifier

FIDC010466

Recommended Citation

Vutukuru, Krishna Sai, "Full-Scale Experimental Modeling to Study Wind-Induced Vibrations, Wind Driven Rain and their Effects on Curtainwall Window Systems" (2021). FIU Electronic Theses and Dissertations. 4849.
https://digitalcommons.fiu.edu/etd/4849