| Abstract: | Kerfing is a subtractive manufacturing method to create flexible surfaces from stiff planar materials. While the kerf structures are ubiquitous in indoor and outdoor architectures due to their pleasing aesthetics, they have potential applications for tuning the indoor acoustics and altering the dynamic response of the building from winds, traffics, etc., by varying their geometrical parameters (kerf pattern, cut density, cut thickness, etc.) and locally deforming the kerf cells. This research presents an investigation on the dynamic response, in terms of mode shapes, natural frequencies, and stress wave propagations, of the flexible kerf structures. The influence of material behaviors, i.e., elastic and viscoelastic, on the dynamic response of the kerf cells is also investigated. Mathematical models are used to understand the interplay between material behavior, geometrical kerf pattern, kerf cut density, unit cell size and dynamic responses. Experimental tests using scanning laser vibrometry are performed to study the modal response of kerf structures. Responses from the mathematical models are compared to experimental results in order to validate the modeling approach. Next, the shape reconfigurable behavior and dynamic response of two kerf panels with uniform cut density and transitioning cut density is presented. The flexibility of the kerf panels enables local and global shape reconfigurations, which can alter the dynamic response of the kerf panels. A comparative study on the effect of shape reconfiguration on the modal response and stress propagation behavior of the kerf panel is performed. Additionally, this research presents an investigation of the acoustic characteristics, in terms of normal incidence absorption and transmission loss (TL), of kerf unit cells. The effect of kerf cut density on the acoustic response of a kerf unit cell is first studied using both impedance tube experiments and a finite element (FE) analysis of impedance tube testing. Subsequently, the validated numerical model is used to understand the effect of different kerf patterns and unit-cell reconfigurations on the absorption and TL of kerf unit cells. Understanding the dynamic and acoustic response of kerf structures in association with their geometrical characteristics can lead to a systematic design of kerf structures exposed to various dynamic loadings. The electronic version of this dissertation is accessible from https://hdl.handle.net/1969.1/198584 |
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