Mechanical Engineering Seminar by Dr. Jun Li
When: Wednesday,
April 6, 2016
2:00 PM
-
3:00 PM
Description: Mechanical Engineering (MNE) Seminar
Friday, April 8th, 2016
2:00 p.m. 3:00 p.m.
Textile Building, Room 105A
SPEAKER:
Dr. Jun Li, Software QA Manager at Abaqus Solver Team, Dassault Systems Simulia Corp, RI
TOPIC:
Predictive Modeling of Multiscale Materials
ABSTRACT:
Multiscale approaches of materials modeling are coming of age and represent a technology shift, both from the fundamental scientific and applied industrial perspectives. The use of computation to understand and even design multiscale materials is becoming a trend. However, the predictive power of simulations is hindered by enormous quantities of information across multiple scales. The question is that what level of detail is required to build predictive multiscale models. In this presentation, I will discuss three examples along this line of thought. First, a hybrid experimental-computational procedure is presented for modeling polyethylene thin films used in the NASA Superpressure Balloon. The film is modeled as an orthotropic membrane with a modified analytic form of free-volume, where mechanical dilatation and distorsion affect the temporal scale of polymeric deformation processes from the perspective of relative mobility of molecule network. This allows the model calibrated to capture experimentally characterized behavior of long-duration uniaxial tension and biaxial inflation up to yielding over a wide range of temperatures and strain rates for balloon design. Second, a range of statistical continuum plasticity models were studied to understand the influence of microscale material randomness on macroscopic elastic-plastic transitions. Third, a multiscale analytical approach is described to model trabecular bone with Micro-CT representation of constituent volume fractions at multiple levels. Finally, I will discuss a workflow integrating predictive modeling, optimization design and additive manufacturing of multiscale materials to meet the challenges of material-by-design.
BIO:
Dr. Jun Li is currently a software quality assurance (QA) manager at Abaqus solver team of Dassault Systemes Simulia Corp, RI. Before that, he spent two years as a postdoctoral scholar at the Graduate Aerospace Laboratories in the California Institute of Technology, working on NASA Superpressure Balloon project. He received his Ph.D. in Mechanical Engineering from the University of Illinois at Urbana-Champaign (UIUC) in 2012, as well as M.S. in Mathematics and in Theoretical and Applied Mechanics. At UIUC, he contributed to the mechanics of random and fractal materials leading to over 10 peer-reviewed journal publications and a keynote at the 10th US National Congress on Computational Mechanics. His research interest is to develop advanced theoretical and computational tools combined with experiments for the assessment, design and optimization of novel materials and structures in various applications.
For more information please contact Dr. Mehdi Raessi, MNE Seminar Coordinator (mraessi@umassd.edu, 508-999-8496).
Light refreshments will be served.
All are welcome!
Students in MNE-500 are REQUIRED to attend! All other MNE students (especially MNE Seniors and MS students) are encouraged to attend.
Thank you,
Sue Cunha, Administrative Assistant
Friday, April 8th, 2016
2:00 p.m. 3:00 p.m.
Textile Building, Room 105A
SPEAKER:
Dr. Jun Li, Software QA Manager at Abaqus Solver Team, Dassault Systems Simulia Corp, RI
TOPIC:
Predictive Modeling of Multiscale Materials
ABSTRACT:
Multiscale approaches of materials modeling are coming of age and represent a technology shift, both from the fundamental scientific and applied industrial perspectives. The use of computation to understand and even design multiscale materials is becoming a trend. However, the predictive power of simulations is hindered by enormous quantities of information across multiple scales. The question is that what level of detail is required to build predictive multiscale models. In this presentation, I will discuss three examples along this line of thought. First, a hybrid experimental-computational procedure is presented for modeling polyethylene thin films used in the NASA Superpressure Balloon. The film is modeled as an orthotropic membrane with a modified analytic form of free-volume, where mechanical dilatation and distorsion affect the temporal scale of polymeric deformation processes from the perspective of relative mobility of molecule network. This allows the model calibrated to capture experimentally characterized behavior of long-duration uniaxial tension and biaxial inflation up to yielding over a wide range of temperatures and strain rates for balloon design. Second, a range of statistical continuum plasticity models were studied to understand the influence of microscale material randomness on macroscopic elastic-plastic transitions. Third, a multiscale analytical approach is described to model trabecular bone with Micro-CT representation of constituent volume fractions at multiple levels. Finally, I will discuss a workflow integrating predictive modeling, optimization design and additive manufacturing of multiscale materials to meet the challenges of material-by-design.
BIO:
Dr. Jun Li is currently a software quality assurance (QA) manager at Abaqus solver team of Dassault Systemes Simulia Corp, RI. Before that, he spent two years as a postdoctoral scholar at the Graduate Aerospace Laboratories in the California Institute of Technology, working on NASA Superpressure Balloon project. He received his Ph.D. in Mechanical Engineering from the University of Illinois at Urbana-Champaign (UIUC) in 2012, as well as M.S. in Mathematics and in Theoretical and Applied Mechanics. At UIUC, he contributed to the mechanics of random and fractal materials leading to over 10 peer-reviewed journal publications and a keynote at the 10th US National Congress on Computational Mechanics. His research interest is to develop advanced theoretical and computational tools combined with experiments for the assessment, design and optimization of novel materials and structures in various applications.
For more information please contact Dr. Mehdi Raessi, MNE Seminar Coordinator (mraessi@umassd.edu, 508-999-8496).
Light refreshments will be served.
All are welcome!
Students in MNE-500 are REQUIRED to attend! All other MNE students (especially MNE Seniors and MS students) are encouraged to attend.
Thank you,
Sue Cunha, Administrative Assistant
Topical Areas: General Public, University Community, College of Engineering, Mechanical Engineering, Lectures and Seminars