Department News
Delft 공대 기계과 Fred Van Keulen 교수 그룹 세미나
Seminar Date
2005-01-19
Author
임아주
Date
2005-01-19
Views
1908
1. 제 목 : Delft 공대 기계과 Fred Van Keulen 교수 그룹 세미나
2. 일 시 : 2005년 1월 21일 금요일 14:00 ~ 17:00
3. 장 소 : 서울대학교 301동 1512호 세미나실
4. ABSTRACT
“Research at the Department of Precision and Microsystems Engineering of Delft University, Netherlands”
14:15-14:45, by Prof. Fred van Keulen (Delft University)
An overview of current and future research at the Department of Precision and Microsystems Engineering (PME) will be given. The Department PME belongs to the Faculty of Mechanical Engineering and Marine Technology, Delft University of Technology. PME is the anchor point of the Delft Research Centre Mechanics and Microsystems" and leads the national research program MicroNed. Current research activities are centered around research groups on mechatronics, production technology and mechanics. For each of these groups, a few examples of ongoing research projects will be given. Typically, these research projects are carried out in collaboration with industrial partners, e.g. ASML, Philips, Airbus, and/or with the Delft Institute of Microelectronics and Submicrontechnology (DIMES). A clear trend in PME's research activities is to focus more and more on micro-components and micro-systems. For that reason, the PME research groups have recently joined the DIMES institute.
“Topology Optimization of Shape Memory Alloy Structures Using Element Connectivity Parameterization”
16:00-17:00, by Matthijs Langelaar (DelftUniversity)
In this seminar the first application of topology optimization to the design of shape memory alloy structures is presented. This is a challenging problem, because the material behavior of shape memory alloys is strongly nonlinear and temperature-dependent. For the topology optimization, a recently developed problem formulation is employed, which defines the problem in terms of element connectivity. The advantages of this approach over the conventional density-based method will be discussed. The effectiveness of the topology optimization of shape memory alloys is demonstrated by several examples, that reveal various aspects of the nonlinear nature of this class of problems. This work has been carried out for the past 2 months at the Multiscale Design Center at Seoul National University.
“Fast Reanalysis and Sensitivity Analysis”
14:45-15:45, by Prof. Fred van Keulen (Delft University)
Fast reanalysis is very attractive in situations requiring finite element evaluations for many configurations with relatively small differences. Characteristic examples can be found in (structural) optimization and reliability-based analysis. Kirsch's “Combined Approach” (CA) is among these reanalysis techniques. The CA relies on a reduced-basis technique, using basis vectors which have been constructed recursively. The method performs well for a wide range of applications. However, a more carefully inspection reveals that the second basis vector resembles a semi-analytical design sensitivity. Semi-Analytical Design Sensitivities (SADS) have a bad reputation if applied to shape design variables. Depending on the nature of the structural problem at hand, severe accuracy problems may emerge. Particularly for slender structures exhibiting rotations, extreme inaccuracies can be observed. Thus, the method is likely to fail for membrane- and MEMS-type of applications. With this knowledge in mind, the question must be raised, whether the “Combined Approach” also suffers from defects known from SADS.
In the present study, it will be demonstrated that the CA is indeed hindered by the same defects known from SADS. Remedies will be proposed and their efficiency will be studied. In addition, directions for future research will be given.
5. 문 의 : 기계항공공학부 김윤영 교수 (☏880-7154)
2. 일 시 : 2005년 1월 21일 금요일 14:00 ~ 17:00
3. 장 소 : 서울대학교 301동 1512호 세미나실
4. ABSTRACT
“Research at the Department of Precision and Microsystems Engineering of Delft University, Netherlands”
14:15-14:45, by Prof. Fred van Keulen (Delft University)
An overview of current and future research at the Department of Precision and Microsystems Engineering (PME) will be given. The Department PME belongs to the Faculty of Mechanical Engineering and Marine Technology, Delft University of Technology. PME is the anchor point of the Delft Research Centre Mechanics and Microsystems" and leads the national research program MicroNed. Current research activities are centered around research groups on mechatronics, production technology and mechanics. For each of these groups, a few examples of ongoing research projects will be given. Typically, these research projects are carried out in collaboration with industrial partners, e.g. ASML, Philips, Airbus, and/or with the Delft Institute of Microelectronics and Submicrontechnology (DIMES). A clear trend in PME's research activities is to focus more and more on micro-components and micro-systems. For that reason, the PME research groups have recently joined the DIMES institute.
“Topology Optimization of Shape Memory Alloy Structures Using Element Connectivity Parameterization”
16:00-17:00, by Matthijs Langelaar (DelftUniversity)
In this seminar the first application of topology optimization to the design of shape memory alloy structures is presented. This is a challenging problem, because the material behavior of shape memory alloys is strongly nonlinear and temperature-dependent. For the topology optimization, a recently developed problem formulation is employed, which defines the problem in terms of element connectivity. The advantages of this approach over the conventional density-based method will be discussed. The effectiveness of the topology optimization of shape memory alloys is demonstrated by several examples, that reveal various aspects of the nonlinear nature of this class of problems. This work has been carried out for the past 2 months at the Multiscale Design Center at Seoul National University.
“Fast Reanalysis and Sensitivity Analysis”
14:45-15:45, by Prof. Fred van Keulen (Delft University)
Fast reanalysis is very attractive in situations requiring finite element evaluations for many configurations with relatively small differences. Characteristic examples can be found in (structural) optimization and reliability-based analysis. Kirsch's “Combined Approach” (CA) is among these reanalysis techniques. The CA relies on a reduced-basis technique, using basis vectors which have been constructed recursively. The method performs well for a wide range of applications. However, a more carefully inspection reveals that the second basis vector resembles a semi-analytical design sensitivity. Semi-Analytical Design Sensitivities (SADS) have a bad reputation if applied to shape design variables. Depending on the nature of the structural problem at hand, severe accuracy problems may emerge. Particularly for slender structures exhibiting rotations, extreme inaccuracies can be observed. Thus, the method is likely to fail for membrane- and MEMS-type of applications. With this knowledge in mind, the question must be raised, whether the “Combined Approach” also suffers from defects known from SADS.
In the present study, it will be demonstrated that the CA is indeed hindered by the same defects known from SADS. Remedies will be proposed and their efficiency will be studied. In addition, directions for future research will be given.
5. 문 의 : 기계항공공학부 김윤영 교수 (☏880-7154)
