Welcome!

My name is Hongcheng Tao (陶泓成) and I am currently a Postdoctoral Researcher in Mechanical Engineering, Purdue University, where I earned my PhD working with my advisor Prof. James M. Gibert.

I enjoy exploring the rich behaviors of dynamical systems with various nonlinearities and I am devoted to applying numerical continuation methods for revealing every detail of their responses, especially for systems with non-smooth and discontinuous features.

I am also interested in the mysterious mechanism of triboelectricity and have based my dissertation on the experimental examination of Paschen's law for gas breakdown in the separation phase of contact electrification, as well as the quantification of post-contact dielectric surface charge densities.

I have also worked on applications of mechanical metamaterials with self-sensing and programmable functions.

Research

Numerical Continuation on Periodic Orbits of Non-Smooth Dynamical Systems

A numerical continuation scheme can successfully solve periodic orbits of nonlinear dynamical systems, regardless of their stability. It can even be applied on systems with extremely strong nonlinearities such as mechanical impacts, whose behavior may reveal the most intrinsic properties of the general family of polynomial nonlinearities since fundamental bifurcation points can now be identified distinctly without the interference of grazing-induced ones. Solution branches of a vibro-impact system thus develop in a comparatively structured manner so that the fascinating infinite cascades of subharmonic period-multiplying bifurcations can be studied in a systematic way.

A Slice of the Solution Manifold (in State Space) of a Conservative 2-DOF Oscillator Evolving from Impact to Cubic Nonlinearity

Frequency-Energy Plot of a Conservative 2-DOF Vibro-Impact Oscillator

Surface Charge Transfer and Dissipation in a Complete Dielectric Contact Electrification Cycle

Gas Breakdown in Dielectric Contact Electrification

The charge transferred during contact electrification typically generates an electric field high enough to trigger the breakdown of the gas which fills the gap when the surfaces separate. It is widely accepted that this process obeys the classic Paschen's law and test setup is developed here to experimentally verify this assumption for situations where one or both of the surfaces are insulators. The results provide confidence for the quantification of triboelectric charge transfer excluding the disturbance of breakdown-induced dissipation.

Heterogeneous Digital Stiffness Programming

A programmable material allows tunable mechanical properties. With a heterogeneous design, linear stiffness programming is achieved with a maximized range and a resolution that increases exponentially with the number of unit cells. 

A Programmable Mechanical Metamaterial with Pattern-Dependent Responses

Mechanical Metamaterials with Embedded Triboelectric Sensors

Self-Sensing Mechanical Metamaterials

A mechanical metamaterial can be augmented with embedded flexible triboelectric sensors which provides practical capabilities such as self-powered vibration and shock sensing as well as energy harvesting in operation. 

Mechanism of a Classical Triboelectric Generator

Publications

Journal Papers

Conference Papers

Email: taoh@purdue.edu