Instabilities and Elastic Waves in Microstructured Soft Composites

Jian Li
Work towards PhD degree under the supervision of Asst. Prof. Stephan Rudykh
Department of Aerospace Engineering
Technion – Israel Institute of Technology

Abstract:

Understanding of the mechanical behavior of soft composites is essential for many research fields and applications such as ultrasound diagnostics, vibration mitigation, adhesives, packaging materials, and biological tissues. The properties of soft composites can be tailored through designing their microstructures. Moreover, thanks to the ability of soft materials to sustain large deformations, their behavior can be tuned by deformations. Moreover, large deformation induced elastic instabilities, and associated dramatic structural and local material property changes, can be utilized to design reconfigurable materials.

In this talk, we will start with examining elastic instability phenomena in various microstructured soft systems. We will first investigate the onset of instability in layered composites and 3D fiber composites. We will examine the role of compressibility and fiber arrangement on the onset of instability. Next, we will discuss the domain formation and its transition to cooperatively wavy pattern via instabilities in soft particulate composites. We will show that these patterns can be tailored by altering the initial microstructural periodicity and concentration of the inclusions. Then, we will investigate the instability-induced pattern transformations in multiphase composites consisting of stiff inclusions and voids periodically distributed in a soft matrix. Distinct patterns characterized by significantly different negative Poisson’s ratio (NPR) behaviors will be discussed; moreover, we will show that the mechanical responses and auxetic behaviors can also be tuned by inclusion distribution. Finally, we will illustrate an application of employing these reversible pattern transformations to manipulate elastic wave propagation.

The talk will be given in English

Mon, 08-07-2019, 16:30 (Gathering at 16:00)

Classroom 165, ground floor, Library, Aerospace Eng.

Light refreshments will be served before the lecture


Instabilities and Elastic Waves in Microstructured Soft Composites