Wind-induced Dynamic Behavior of Building Envelopes: A Numerical Study on Glass Curtainwalls and Operable Window Systems

Authors

Ali Bakhtiari, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Civil Engineering

First Advisor's Name

Seung Jae Lee

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Arindam Gan Chowdhury

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Amal Elawady

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Ioannis Zisis

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Nipesh Pradhananga

Fifth Advisor's Committee Title

Committee member

Keywords

Wind-induced vibration, curtainwall, wind-tunnel test, time history analysis, finite element analysis, NHERI Wall of Wind Experimental Facility

Date of Defense

6-28-2023

Abstract

The inadequate performance of building envelopes contributes significantly to financial losses in coastal regions of the United States caused by hurricanes. Glass curtainwalls, commonly used as building envelopes, are highly vulnerable to extreme wind loads and susceptible to failures due to excessive vibrations during windstorms. These failures are primarily attributed to wind-induced vibrations resulting from strong gusts, leading to damage. Such curtainwall failures can compromise the water tightness of building envelope systems, allowing water infiltration during storms and rendering the building unusable, even if the main wind-resisting system remains structurally intact. The ASCE 7 standard requires dynamic analysis to assess the impact of wind on structures but does not mandate the analysis of structures with natural frequencies exceeding 1 Hz for wind-induced dynamic effects.

This study aims to address knowledge gaps related to the effects of wind-induced vibrations on the dynamic behavior of single-skin façade, double-skin façade curtainwalls, and operable window systems. Comprehensive finite element analyses are conducted to simulate the dynamic response of the curtainwall systems. Experimental data from full-scale wind tunnel tests on single-skin and double-skin façade curtainwall specimens at the NHERI Wall of Wind Experimental Facility are used to validate the results.

The findings highlight the significant influence of the supporting structure on the wind-induced dynamic behavior of the façade, emphasizing the importance of considering the interaction between the building structure and the façade. Prominent responses are observed at frequencies above 4 Hz, indicating that curtainwall window systems, currently exempt from vibration analysis as per the ASCE 7 Standard, may be prone to damage or failure due to wind-induced vibrations. Vertical protrusions attached to the façade are found to amplify wind-induced vibrations in the curtainwall’s glazing unit, posing additional risks. The study reveals that operable window systems and their connections are vulnerable to potential failure due to wind-induced vibrations, particularly in open condition.

Moreover, defects causing increased cavity permeability in double-skin façade curtainwalls result in higher vibration levels, with greater impact observed in the internal glazing. These consequences are exacerbated in higher wind speeds, increasing the likelihood of water infiltration in vented-cavity double-skin facade systems compared to closed-cavity configurations.

Identifier

FIDC011206

ORCID

https://orcid.org/0000-0003-4286-5400

Recommended Citation

Bakhtiari, Ali, "Wind-induced Dynamic Behavior of Building Envelopes: A Numerical Study on Glass Curtainwalls and Operable Window Systems" (2023). FIU Electronic Theses and Dissertations. 5360.
https://digitalcommons.fiu.edu/etd/5360