- Ph.D. in Mechanical Engineering, 2009, University of Manchester, Manchester, UK
- M.S. in Aerospace Engineering, 2003, Beijing Univ. of Aero. & Astro., Beijing, China
- B.S. in Aerospace Engineering, 2000, Beijing Univ. of Aero. & Astro., Beijing, China
- Solid background in Mechanical Engineering, Aerospace Engineering and Materials Science.
- Experience in FEA analysis of fatigue crack initiation and propagation, structural vibration, structural fracture, creep rupture, thermal stress problems and component life prediction.
- Extensive engineering experience in FEA software (Sierra, ABAQUS, ANSYS, Hypermesh, MSC MARC, LS-DYNA), multiple programming languages (FORTRAN, MATLAB, Python, Visual Basic, VBA, C, C++, C#, XML and etc.) and 3D modeling software (AutoCAD, Solidworks, Pro/E, UG NX).
- Proficient with database systems MS SQL Server, Oracle, MySQL, familiar with SQLite, PostgreSQL and MongoDB; familiar with high-throughput scientific workflow software FireWorks.
- Rich experience in the application of material models, familiar with test standards ISO 6892 (Tensile), ISO 12106 (Fatigue), ASTM E139 (Creep), ASTM E1820 (Fracture), ASTM E1457 (Creep Crack Growth), ASTM E647 (Fatigue Crack Growth), ASTM C749 (Graphite Tensile Test) and ASTM D8289 (Graphite Disc Compression Test), familiar with ASME Boiler and Pressure Vessel Code (BPVC). Professional in MTS servo-hydraulic test system.
Mechanical Properties and Mechanics, Oak Ridge National Laboratory 2016 - Now
- Nuclear Graphite Mechanical Properties Characterization Project. Task leader to apply digital image correlation (DIC) method with graphite disc compression test to record not only the tensile strength of graphite samples, but also the stress/strain relation during the test, and evaluate the elastic moduli for a specific graphite grade through this technique.
- Battery Thermal Runaway Evaluation Project. Task leader to develop a Li-ion battery thermal runaway risk database for energy storage systems, understand and manage the safety risks of Li-ion batteries in energy storage systems, especially for thermal runaway.
- Second Target Station Thermal-Structural Analysis Project. Task leader to use the Sierra/SolidMechanics simulation code to perform thermal-structural analyses of tungsten spallation target concepts at Second Target Station (STS) at ORNL. Simulation results proved that Sierra is capable to simulate such thermal-structural dynamic response for tungsten target system when it’s pulsed by high energy proton beams.
- Corrosion Probe Stress and Fatigue Analysis. Use finite element software ABAQUS to analyze the stress distribution on a corrosion probe sample holder in a Steam Reformer vessel under static and dynamic loads. Based on the stress results, fatigue evaluations were performed to provide suggestions for the design of corrosion probe. The analysis was done for ThermoChem Recovery International (TRI), and a technical report was submitted at the end of this project.
- Target Machine Learning Project. Subtask leader to combine the power of machine learning, HPC resources and expertise at national laboratories for pursuing a better mechanical response prediction of gas injected mercury target at Spallation Neutron Source (SNS), and an extended lifetime of it. The project was funded at the end of FY20 and reaches its milestones in FY21 to perform large-scale full target simulations on Argonne Leadership Computing Facility (ALCF) Theta machines.
- T25 Target Strain Data Comparison. Lead simulation engineer to collect and compare sensor strain data of Spallation Neutron Source (SNS)’s T25 mercury target. Different metrics were introduced to validate target’s FE simulation model by comparing the FE simulation results with experimental measurements on mercury target’s strain sensors. Strain comparison between simulations and measurements showed a good match at some sensor locations by using the current EOS mercury material model when helium was not included in mercury. Significant strain discrepancy was observed between measurements and simulations when helium gas was injected into flowing mercury, which indicated the deficiency of current mercury material model in simulating the gas-on state.
- T22 Target Leak Investigation. Lead simulation engineer to investigate crack initiation of Spallation Neutron Source (SNS)’s T22 mercury target. By comparing the FE simulation results of Blue target design and Jet-Flow target design, high stress concentration and low fatigue life were identified at the local region (a square corner, the location of crack initiation) due to pulse load for the Blue T22 target. New geometric feature was identified as a potential crack initiation region, and it was verified by the FE simulations that new feature not only removes the stress singularity, but also significantly alleviates the stress concentration at that local region to improve target’s structural integrity.
- Development of User Material Model and Dynamic Simulation for Neutron Target System. Lead simulation engineer to help Spallation Neutron Source (SNS) at ORNL investigate the dynamic behavior of mercury contained neutron Target system. Based on ABAQUS user subroutine VUMAT, different user-defined material models have been developed to introduce bubble behaviors into mercury liquid. Along with the advanced user-defined materials, explicit simulations of full size neutron Target system have been compared with experimental measurements to provide useful information for further Target design.
- Structural Analyses of PPU Test Target System. Lead engineer to analyze the structural response of Proton Power Upgrade (PPU) Test Target under static loads (gravity, hydrostatic pressure, internal pump pressure, thermal load) and predict its working life under these designed static loads. PPU Test target will provide risk mitigation by testing several new target design features before the use of the final PPU targets. Static simulations are performed through ABAQUS and life predictions are made from FE-SAFE. The structural simulations and structural integrity analysis provide important information for PPU Test Target’s design and manufacturing.
- Investigation of Thermal Embrittlement Effect on Structural Alloys in Nuclear Engineering. Co-PI to review the thermal embrittlement effect on structural alloys utilized in nuclear engineering, such as 316H, Gr91, 800H, that experienced long-term service at elevated temperatures. The literature survey revealed that thermal embrittlement effect in the desired high temperature range and long-term life span has not been sufficiently studied to provide robust technical basis for the advanced non-light water reactors (ANLWR) operations. Some survey results do raise a concern of adverse thermal embrittlement effects on performance of structural alloys in the expected ANLWR working conditions.
- Development of Gen IV Database Infrastructure. As a developer of this Gen IV Materials Database system, I keep introducing new schemas into the database, and propagating its contents. This database system hosts several advanced database and knowledgebase systems including the Gen IV Materials Handbook, an international structural materials digital database that provides a platform for more than 10 countries to share materials information for Generation IV Nuclear Energy Systems development. Knowledge of materials behaviors, including mechanical properties, fatigue and creep behaviors, thermal properties, electrical properties and effects of irradiation, etc., and the techniques of database programming are involved in the development of Handbook system. The digitized experimental materials data, along with the numerical simulation results from Abaqus, Ansys and so forth, provides a solid support for verification and validation. Part of the Handbook database content is prepared for the ASME Pressure Vessels & Piping Codes and Standards.
- Development of Automated in situ Defects Detection Algorithms. Team up with post-docs and student to participate in the contest Smoky Mountains Data Challenge 2018 on the topic of “Automated in situ Defects Detection in Powder Bed Metal Additive Manufacturing Parts.” Within a few weeks, our team delivered Python and C++ Machine Learning algorithms that can detect the edge contours and defects of additively manufactured parts in 1 second according to the requirement of challenge.
- Development of An Integrated Approach to the Design and Discovery of Fast Ionic Conducting Materials. The project aims to computationally optimize crystal structures that are known to exhibit proton/oxygen conductance by using high-throughput modeling, optimizing ionic conductivities and also create a database & query system. Promising materials will be synthesized and characterized using various methods including electron microscopy and neutron scattering. Experimental data will be incorporated into the computational models improving their fidelity, building a powerful integrated “materials by design” infrastructure. I am the database builder and high-throughput framework developer in this project.
- Materials Database Interoperability Project. Lead investigator of project that aims to develop automated materials data exchange between the United States (US)and the European Union (EU) under the US-EU International Nuclear Energy Initiative (I-NERI) sponsored by the US Department of Energy and the European Commission. The developed interface can also be applied as a gateway between materials database and FEA, CAD software (Abaqus, Ansys, Catia, Hypermesh, Autodesk CAD, UG NX, and etc.) for materials properties and test data transportation.
- Development of the Nuclear Energy Knowledgebase for Advanced Modeling and Simulation (NE-KAMS). It was to initiate a framework for systematic information collection and management to enable verification and validation of advanced modeling and simulation. I am the CO-PI of this project and develop the network interface for automatic data communication.
Post-doctoral Research Assistant
Mechanical Properties and Mechanics, Oak Ridge National Laboratory 2012 - 2016
- Development of Gen IV Materials Handbook database.
- Development of NE-KAMS database system.
Pre-doc/Post-doctoral Research Assistant
Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota 2008 – 2012
- Development of an advanced Artificial Mouth by integrating a linear motor and an MTS servo-hydraulic system with VB .NET and C++ algorithms.
- Stress and fatigue analysis of dental composites and structures with an Inverse Method (ABAQUS User Subroutine UMAT) and digital image correlation (DIC).
- Materials characterization of dental composite via optical microscope, SEM, X-ray microtomography (Micro-CT) and 3D image reconstruction software.
School of Mechanical, Aerospace and Civil Engineering, University of Manchester 2005 - 2008
- Characterized the elastic properties of isotropic, orthotropic and inhomogeneous materials by Inverse Method, which hybrids ESPI/DIC experimental data with a customized ABAQUS User Material Subroutine (UMAT).
Department of Civil Engineering, University of Hong Kong 2007
- Fracture simulation and property characterization of concrete with Inverse Method, which were achieved by the combination of the test data of concrete beams under three-point bending, CDM failure model (embedded into ABAQUS via UEL) and Backpropagation Neural Network algorithm in MATLAB.
Software Engineer & Project Manager
Beijing UPS Technology CO., LTD 2004 – 2005
- Develop an ERP System for Daguang Advertising Co. Ltd. VB and C# were the main languages in the software development.
- Develop a Human Resource Management System—Time3 Online Software for Beijing UPS Technology Co., Ltd, the database is based on PostgreSQL.
- Develop a Tiny Sound Recorder and Player Software, to be used in Toshiba PC System.
Software Engineer & Project Manager
Beijing Sysnet Info-Tech CO., LTD 2003 – 2004
- Project Manager and major software developer in the project of “Chongqing City Online Environmental Pollution Monitoring Mapinfo System”. The main software developing tools were Visual Studio 6.0, Oracle Database 8i and MapXtreme.
Department of Jet Propulsion, Beijing University of Aeronautics and Astronautics 2000 – 2003
- Modal analysis of a complicate component of aero engine with ANSYS. The analysis included a nonlinear boundary and a coupled aerodynamic load. The modal results provided a good prediction for the real engine component.
- Develop software to export thermal images from a thermographic device, which help to rebuild the accurate temperature distribution (around 1000˚C) of test specimen for further creep-fatigue analysis.
- Damage calculation of a 2D specimen with Fortran User Subroutine and determine its crack initiation and fatigue life with FEA software, MSC.MARC.
- High-temperature creep and fatigue life prediction of an aero engine structure by using ALGOR and ANSYS. The analysis results were verified with high-temperature cycling tests on full size component, which utilized a Thermo Video System to monitor the temperature (1000˚C) distribution.
- Development of a novel parametric procedure in designing test samples with MathCAD.
The University of Manchester Oversea Research Scholarships (ORS) Award, 2005 - 2008