Dengge (Grace) Jin Master Student, major in Engineering Mechanics Department of Engineering Mechanics School of Aerospace Engineering Tsinghua University Email: jdg20@mails.tsinghua.edu.cn Phone: +86 18800133990 Github: github.com/DenggeJin

• Master of Science              2020.09-2023.06    Solid Mechanics               Tsinghua University
• Bachelor of Engineering    2016.09-2020.06    Engineering Mechanics    Tsinghua University

• Teaching Assistant    Spring Semester 2022     Course: Finite element method for undergraduate

Mechanics and Morphology of Stiff Film/Soft Subtrate Hyperelastic Bi-layer System | Summer Research
Time: 2022.05-date
Advisor: Rui Huang, Professor at Department of Aerospace Engineering & Engineering Mechanics, University of Texas at Austin, U.S.A.
Paper: Periodic ridge formation in elastic film-substrate system (in preparation), Jin D., Huang R.,2022


• Conducted systematic Abaqus simulations to investigate the sequential morphology bifurcations of the thin film/soft elastomer bilayer system under pre-stretch and compression. The Periodic ridge formation and secondary wrinkling were focused on quantificationally for the first time.
• Established a morphology phase diagram according to the simulation results, based on which controlled morphology can be achieved by adjusting two critical parameters, i.e. the pre-stretch and compression.
• Revealed the mechanism of wrinkling to periodic ridge formation transition that the softening/hardening effects by pre-stretch and compression result in multi-stable surface morphology, and revealed for the first time the negative correlation between the spacing of periodic ridge and the pre-stretch.





Nonlinear Thermal-Mechanical Behavior of Slender Beam/Arch | Master thesis
Time: 2020.09-date
Supervisor: Zhihai Xiang , Associate Professor at Department of Engineering Mechanics, Tsinghua University, China
Publication:
(1) Experimental Verification of the Thermal Flutter Criterion for a Slender Cantilever Boom. Jin D., Fan C., Wang J., Bi Y., Su X., Liu G., & Xiang Z., AIAA Journal, 2022
(2)Predicting the on-orbit thermally induced vibration through the integrated numerical and experimental approach.. Wang J., Jin D., Fan C., Bi Y., Su X., Liu G., & Xiang Z. Acta Astronautica, 2021.


• Proposed a Finite element formulation which considers the thermal-elastic constitutive model and heat flux-structure nonlinear coupling effect to simulate the thermally induced vibration (TIV), and independently developed an efficient and accurate code pack programmed by Fortran;
• Clarified the mechanism of the stability of TIV. Based on FEM simulation, theoretical analysis, and experiments, demonstrated that the phase difference between oscillating thermal stress and the generalized displacement determines whether the accumulated total energy is positive, and thus determines the stability;
• Derived theoretical governing equations and solutions for the buckling of arches under gradient temperature field and mechanical load, and studied the effect of temperature distribution on buckling mode and associated critical temperature/mechanical load.





Anisotropic Nonlinear Kinematical Hardening Elastoplastic Constitutive Model | Course Project for Nonlinear Finite Elements for Continua and Structures
Time: Spring semester 2021
Advisor: Zhuo Zhuang, Professor at Department of Engineering Mechanics, Tsinghua University, China
Report:
Anisotropic Nonlinear Kinematical Hardening Elastoplastic Constitutive Model. Jin D., Ji C., Wang Z., 2021


• Derived the Hill48-A-F elastoplastic constitutive formulation by combining Hill48 anisotropic yield criterion and Armstrong-Frederick (A-F) nonlinear kinematic hardening model;
• Implemented the elastoplastic model in Abaqus by programming in the user-defined material subroutine UMAT;
• Parametric study: investigated the influence of hardening and anisotropic parameters on the elastoplastic material, simulated Bauschinger effect under cyclic loading, and finished corresponding Course Project Report





Dynamics of Flexible Multibody Systems | Research Assistant Internship
Time: 2019.07-2019.09
Organization: Tsien Hsue-shen Laboratory, China Academy of Space Technology, Beijing

• Studied Absolute Nodal Coordinates Formulation theory which is a good tool to simulate the dynamics of flexible multibody systems by extensive and thorough literature research;
• Implemented this theory by developing a code pack programmed by mixed Fortran/Matlab;
• Simulated the dynamic free downswing of a flexible double pendulum system, and conducted the parametric study to investigate the effects of geometry and mechanical parameters.