University of Michigan College of Engineering

Dr. Anatole S. and Pamela D. Dekaban Fund

2004-05 Annual Report

Prepared by Professor Radoslaw L. Michalowski

Dekaban Program Coordinator

October, 2005

Museum of the Warsaw University of Technology

housed in early 20th century brick building of Aerodynamics Institute

Table of Contents

Executive Summary 3 2004-2005 Activities

Administrative Activity 4 Dekaban Fellowships 6 WUT Interactions with U-M 9 U-M Interactions with WUT 10 Other Related Activities 12 Dekaban Fund Advisory Council 13

2005-2006 Plans and Activities to Date 14 Financial Report 15 Appendices Appendix A: Dekaban Fund Advisory Council and Program Committee i Appendix B: Dekaban Fellow Profiles iii Appendix C: Visitor Profiles v

Appendix D: Dekaban Fund Endowment Agreement x Appendix E: Dekaban Fund Website Address xii Appendix F: Abstracts of Publications Related to Dekaban Fellows Program xiv

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Executive Summary The Dekaban Program was created in 1993 with the gift of Dr. Anatole S. and Mrs. Pamela D. Dekaban. Its purpose is to encourage the exchange of technical knowledge between advanced academic professionals in various fields of engineering at Warsaw University of Technology (WUT) in Warsaw, Poland, and at the University of Michigan (U-M) College of Engineering (CoE) in Ann Arbor, Michigan. The primary activities of the program are sponsored fellowships which enable junior faculty from WUT come to the University of Michigan to collaborate with faculty, gain experience in their respective fields, and promote future joint research efforts. Two Dekaban Fellows visited U-M during fiscal year 2005 (July 1, 2004-June 30, 2005) and arrangements were made for the next fellow, Dr. Aradiusz Kobiera, to join U-M in July, 2005. This is the twelfth year of the Program’s existence and, thus far, eighteen fellows have visited various departments in the U-M College of Engineering. This past year several senior members of the College of Engineering faculty visited Warsaw University of Technology; these visits were reciprocated by the WUT faculty visiting Ann Arbor. WUT is a U-M prime international partner institution and efforts were made this year to extend the cooperation for student exchange, both undergraduate and graduate students. Funding options for the exchange are being discussed at both U-M and WUT. Former Dekaban Program Coordinator Professor Andrzej Nowak accepted the position of the Robert W. Brightfelt Professor of Engineering at the University of Nebraska, Lincoln in December, 2004. With Professor Nowak retiring from the University of Michigan, Professor Radoslaw L. Michalowski of the Department of Civil and Environmental Engineering assumed the role of coordinator of the Dekaban Program. The Fund is fiscally healthy, and the activities planned for FY2006 include a long-term visit of one fellow and several short visits of the senior faculty. The program will also facilitate donation of computer equipment from U-M College of Engineering’s Computer Aided Engineering Network (CAEN) to Warsaw University of Technology.

2004-2005 Activities1

Administrative Activity Radoslaw L. Michalowski Professor Andrzej Nowak stepped down as the Coordinator of the Dekaban Program as he accepted a position of Robert W. Brightfelt Professor of Engineering at the University of Nebraska. Professor Radoslaw L. Michalowski was appointed as the next Coordinator. In the past 20 years Professor Michalowski served as a faculty member at the University of Minnesota, Johns Hopkins University, and, for the last 6 years at the University of Michigan. He is a faculty member of the Department of Civil and Environmental Engineering at U-M.

During the meeting with the WUT Dekaban Program Committee in June, 2005; Left to right: Professor R. Michalowski, Professor W. Wlosinski,

Professor L. Dabrowski, Professor W. Radomski, Professor Kozak, Professor P. Wolanski and Professor M. Jarosz

1 The part of this Report pertaining to the first half of FY 2005 has been prepared based on information supplied by Professor Andrzej Nowak, the former Dekaban program coordinator.

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Since assuming the role of coordinator of the Program in January, 2005, Professor Michalowski met several times with Associate Dean for Graduate Education Stella Pang and discussed the plan for activities in 2005 and 2006. In May he met with the Chairman of the Dekaban Program Advisory Council, Dr. Thaddeus Radzilowski, and discussed activities for the rest of the fiscal year. Professor Michalowski visited Warsaw University of Technology in June, 2005, met with the Dekaban Program Committee, and visited several departments. He also met with the candidate for the Dekaban Fellowship, and made plans for his arrival in Ann Arbor in mid-July. In August, the College of Engineering hosted Professor Piotr Wolanski, who met with Dean Pang and Professor Michalowski to discuss the program and possible extension to include student exchange. The latter, however, is an independent enterprise, and will not be fiscally related to the Dekaban Program. Stella Pang Associate Dean for Graduate Education, Stella Pang (U-M, Electrical Engineering and Computer Science) serves as Michigan’s chief administrative officer overseeing international programs, including the Dekaban Program. Thaddeus Radzilowski Dr. Radzilowski is the Chairman of the Dekaban Program Advisory Council, and president of the PIAST Institute. He met with the current program coordinator in May, 2005. Dr. Radzilowski will call a meeting of Council in early fall, 2005. Wladyslaw Wlosinski Professor Wlosinski (WUT, Industrial Engineering), member of the Dekaban Ad Hoc Academic Program Committee at WUT, is also chair of the Engineering Division, Polish Academy of Sciences. Professor Wlosinski visited the College of Engineering in September, 2004. Piotr Wolanski Professor Wolanski (WUT, Power and Aeronautical Engineering) is Vice-President for Research at WUT, and is responsible for International Programs. His role at WUT correlates to Associate Dean Stella Pang’s role with the Dekaban Fund at U-M. Professor Wolanski presides as the ex-officio chair of the Dekaban Program Committee at WUT. He visited the College of Engineering from July 31-August 3 of 2004, and August 6-9 of 2005.

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Dekaban Fellowships Dekaban Fellows are recruited predominantly from the Assistant Professor rank of faculty at Warsaw University of Technology. The candidates can come from any department that has a counterpart at the College of Engineering at the University of Michigan. Consistent with the wish of the donors, Dekaban Fellowships are a key element of the Dekaban Program. These are long-term fellowships, 6 to 12 months, and their purpose is the continuation of the education and research of the junior faculty members, exposure to a different research culture, and giving the fellows an opportunity to extend their network of contacts. Two fellows were present at the College of Engineering in the past fiscal year: Dr. Marek Rebow and Dr. Ewa Szeliga.

Dekaban Fellows Ewa Szeliga and Marek Rebow in Ann Arbor

Marek Rebow Marek Rebow visited the University of Michigan from August, 2003 to August, 2004. As the majority of his fellowship was carried out in FY2004, his U-M experience was highlighted in the 2004 Dekaban Report. To recap, Dr. Rebow was a Visiting Assistant Research Scientist in the U-M Department of Mechanical Engineering and an Assistant Professor in the Faculty of Power and Aeronautical Engineering at WUT. While in Ann Arbor, he was hosted by Professor Steven Ceccio, in the Department of Mechanical Engineering. His research has focused primarily on the examination of extremely elongated cavitation bubbles through experiments and numerical simulation. The experimental results will be useful for the validation of the numerical code. This research has applications in various fields ranging from naval architecture (hydrofoils and propeller blades) to biomedical science and aerospace technology.

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Ewa Szeliga Dr. Ewa Szeliga joined the Dekaban Program as the 19th Dekaban Fellow, working at the College of Engineering from August, 2004 to February, 2005.

An Assistant Professor in The Computer Methods Center of the Faculty of Civil Engineering of Warsaw University of Technology, Dr. Szeliga teaches Engineering Mechanics and the basics of computer science and programming. The focus of her research is the reliability of structures. Dr. Szeliga’s additional research interests are in the area of artificial intelligence techniques (fuzzy logic, neural networks and genetic algorithms).

Dekaban Fellow Ewa Szeliga at Niagara Falls

Dr. Szeliga considers her short visit at U-M as very important for her academic development, an experience she would not have been afforded without the Dekaban Program. She had a unique opportunity to work with Professor Nowak and his research team on the calibration of Building Code Requirements for Structural Concrete (ACI 318-02), a project sponsored by the Portland Cement Association. Through her work, she gained valuable practical experience in the application of reliability theory techniques. The results and conclusions will be presented in the final report, “Reliability-Based Calibration for Concrete Structure–Phase 3,” and will be published in ACI Journal.

When asked about her impressions of the United States, she replied, “This country is so different than any other I have ever seen in Europe, as it seems to be another planet, but the most impressive things for me are gigantic American cities like New York or Chicago–super modern and old fashioned in the same time–previously, I was only able to

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see them in movies and I never dreamed that I would have the chance to visit them myself.”

With respect to her thoughts about U-M, Dr. Szeliga commented that the library resources and laboratories are terrific and that “American students are amazing – hard-working and reliable - it must be a real pleasure for teachers to work with them.” She was also impressed with the collaborative working relationships between educators and students at Michigan Engineering.

Dr. Szeliga returned to Poland in February, 2005. Prior to her departure, when asked what she will miss most about her experience in Ann Arbor, she responded, “Excellent coffee flavored ice cream at Starbuck’s, crazy American football games, magic Halloween masquerades, purple sunrises seen from her apartment at Huron Towers, and most of all, the house of Professor Nowak,” where she spent wonderful time with his family and friends.

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WUT Interactions with U-M Aleksander Szwed Aleksander Szwed is a former Dekaban Fellow, but has been a visitor in 2004 and 2005 working on a technical project with Associate Research Scientist Maria Szerszen at the Department of Civil and Environmental Engineering. Dr. Szwed holds a position of an Assistant Professor in the Institute of Structural Mechanics of the Department of Civil Engineering at Warsaw University of Technology.

Former Dekaban Fellow Aleksander Szwed visited U-M in 2005 Dr. Szwed has been working on analysis and testing of restrained shrinkage effects causing premature cracking of bridge decks and analysis of flexural behavior of engineered cementitious composites (ECC) with application to bridge decks. Szwed’s work in Poland focused primarily on the strength of materials, the theory of elasticity and plasticity continuum mechanics, and numerical methods in mechanics. physics and soccer. Tomasz Lewinski Professor Tomasz Lewinski (WUT, Institute of Engineering Mechanics) visited U-M in August 22-September 5, 2004. He met with Professors Nick Triantaffilidis (Aerospace Engineering), John Taylor (Aerospace Engineering), Sherif E-Tawil (CEE), Jim Wight (CEE), Gustavo Parra (CEE), and Jerry Lynch (CEE) at U-M.

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Wladyslaw Wlosinski Professor Wlosinski visited the College of Engineering from September 15-17, 2004. He met with Associate Dean Stella Pang; then-Dekaban Program Coordinator, Professor Andrzej Nowak; and Professor Michalowski of Civil and Environmental Engineering. Piotr Wolanski Professor Wolanski visited U-M from July 31-August 3, 2004 and also in August, 2005. He met with Associate Dean Stella Pang and with the Dekaban Program Coordinator Radoslaw Michalowski. During his visits, the future Dekaban Program activities were discussed. A possible extension of the existing cooperation to include student exchange was also on the agenda. During his visit to the U-M College of Engineering in August, 2005, Professor Wolanski also met with Interim Dean Ron Gibala. U-M Interactions with WUT Nik Katopodes Professor Nikoloas Katopodes (Chair, U-M Department of Civil and Environmental Engineering) visited the Department of Civil Engineering and the Department of Environmental Engineering at WUT in October, 2004 where he presented a seminar. He also visited the Polytechnic University of Cracow, Department of Environmental Engineering. Sherif El-Tawil Professor Sherif El-Tawil participated in two workshops in Poland, one at WUT. His participation was sponsored in part by the Dekaban Fund and the National Science Foundation. He presented a paper entitled “Vehicle Collision with Reinforced Concrete Bridge Piers.” Michael Flynn Assistant Professor Michael Flynn of U-M’s Department of Electrical Engineering and Computer Sciences visited WUT in July, 2004 where he presented a seminar at the Department of Electrical Engineering. Andrzej Nowak and Ewa Szeliga Professor Andrzej Nowak and former Dekaban Fellow Ewa Szeliga introduced and jointly taught a course at WUT entitled “Reliability of Structures” (February-June, 2005). This course is an important element of civil engineering curriculum. It attracted 30 students last year, and is now a required course for all MS students in structural engineering at WUT. Radoslaw Michalowski Professor Michalowski was invited to present a keynote lecture at the 16th International Conference on Computer Methods in Mechanics in Czestochowa, Poland, June, 2005. His lecture was titled “Modelling of Freezing in Frost-susceptible Soils.” While in Poland, he visited Warsaw University of Technology, and met with the Dekaban Program

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Committee. Also, he visited several departments, and met with Dr. Arkadiusz Kobiera, the next Dekaban Fellow to come to U-M in July, 2005. He also met with Vice-President for Education, Professor Lech Czarnecki.

WUT Vice-President for Education, Professor Lech Czarnecki and Professor Radoslaw Michalowski during their meeting in Warsaw in June, 2005

Andrzej Nowak Professor Nowak visited the Warsaw University of Technology in September, 2004. He presented a general paper at a conference in Krynica organized by WUT; he met also with the Dekaban Program Committee at WUT in October and November, 2004. In June, Professor Nowak with the National Science Foundation, organized the US participation in two workshops: “Analytical Models and new Concepts in Concrete and Masonry Structures” in Gliwice-Ustron (June 12-14, 2005), and the second one at WUT with a similar theme. Professor Sherif El-Tawil of U-M participated in these workshops. Maria Szerszen Associate Research Scientist Maria Szerszen (U-M, Civil and Environmental Engineering) continued her involvement in the Dekaban Program. She assisted with the organization of various Dekaban Program activities.

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Other Related Activites Student Exchange WUT Vice-President for Research Piotr Wolanski visited the U-M College of Engineering from August 6-9, 2005. During his visit, extension of the program was discussed to include student exchange at both undergraduate and graduate levels. Student exchange was initiated earlier with PhD Student Artur Czarnecki, who came from WUT to U-M in January of 2003, and is scheduled to obtain his degree from the University of Michigan in fall of 2005. Mr. Czarnecki’s student exchange was funded by the U-M College of Engineering.

PhD student Artur Czarnecki on the Brooklyn Bridge in New York American Axle & Manufacturing The Chairman of the Dekaban Advisory Council, Dr. T. Radzilowski, and the Dekaban Program Coordinator, Professor Michalowski, were invited to participate in a meeting at the American Axle & Manufacturing (AAM) in Detroit. AAM is a major supplier of axles for a variety of automobiles, from light passenger cars to trucks. Present at the meeting were: R.A. Schoenbach, executive director; P.S. Lancaster, vice president; J.E. Jerge, vice president; and D.J. Kurecka, manager. AAM plans to build one of its plants in Europe, either in Slovakia or Poland. The representatives of AAM were interested in the engineering culture in Poland, availability of talent, and the industrial environment in the region of Lower Silesia where the plant might be built. After the talks the guests (Radzilowski and Michalowski) received a guided tour of the axle testing plant.

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Dekaban Program Advisory Council Dr. Thaddeus Radzilowski, Chairman of the Dekaban Advisory Council, met with Professor Michalowski in May, 2005 to discuss future activities within the Dekaban Program. A meeting of the Council will be scheduled for fall, 2005. At that time the Council will meet with the new Dekaban Fellow.

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2005-2006 Plans and Activities to Date Dekaban Fellowship Central to the Dekaban Program are the fellowships extended to the junior faculty at Warsaw University of Technology. Dr. Arkadiusz Kobiera was appointed as the 2005-06 Dekaban Fellow. During his visit to WUT in June, 2005, Professor Michalowski met with Dr. Kobiera and his wife to discuss final arrangements before the Kobieras’ arrival in Ann Arbor in July. Dr. Kobiera will stay at U-M for 12 months.

Dr. Arkadiusz Kobiera, the 2005-06 Dekaban Fellow Working Contacts WUT Vice-President for Education Professor Lech Czarnecki will visit the U-M College of Engineering in the fall of 2005. WUT administration will change in September, 2005. This will not cause any interruptions in the Dekaban Program activities, as the membership on the WUT Dekaban Program Committee is not linked directly to this change, with the exception of the Vice President for Research, who is an ex-officio member. The U-M Program Coordinator, Professor Michalowski, will visit Warsaw in late February or early March, 2006 during the U-M spring break. He will meet with the members of the newly-elected WUT administration and the WUT Dekaban Program Committee. The agenda includes defining the rules for selecting Dekaban Fellows at WUT. Equipment Donation Arrangements will be made for the Dekaban Program to acquire computer systems (CPUs and monitors) from College of Engineering Computer Aided Engineering Network (CAEN) and donate them to Warsaw University of Technology. These computers will be used in the educational programs at WUT.

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Appendices Appendix A Dekaban Fund Advisory Council and Program Committee Dekaban Fund Advisory Council Dr. Anna Bielinska Research Investigator, University of Michigan School of Medicine 1652 Golden Lane Ypsilanti, MI 48198 (734) 487-8623 Mr. Joe Bransky 3816 Autumn Drive Huron, OH 44839 Dr. Karen Majewski Executive Director, Polish American Historical Association The Orchard Lake Schools 3535 Indian Trail Orchard Lake, MI 48324 (248) 683-1743 The Honorable James Nowicki 8180 Anchor Bay Drive Clay, MI 48001 (810) 794-9701 Mr. Richard Prusinski 1726 S. Hill Boulevard Bloomfield Hills, MI 48304 Dr. Thaddeus C. Radzilowski, Chair President, PIAST Institute 2926 Caniff Ave Hamtramck, MI 48212 (313) 664-0321 (313) 664-0326 (fax)

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WUT Dekaban Program Committee Warsaw University of Technology Professor Piotr Wolanski, chair, ex-officio Professor Maciej Jarosz Professor Wojciech Radomski Professor Wladyslaw Wlosinski Dekaban Program Coordinator (U-M College of Engineering) Professor Radoslaw L. Michalowski

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Appendix B

Dekaban Fellow Profiles Name: Marek Rebow Institution: Warsaw University of Technology Department of Power and Aeronautical Engineering Institute of Heat Engineering Thermodynamics Division Tittle: Assistant Professor Address: ul. Korsykanska 7 m 19 02-761 Warsaw POLAND Phone: (+48 22) 660-52-09 Fax: (+48 22) 825-52-70 E-mail: rebow@itc.pw.edu.pl Education: Warsaw University of Technology, MSc ’90, PhD ’01 Research Interests: Experimental and numerical study of the phase change

phenomena (solidification) and two-phase flow (cavitation), vortex flow, flow visualization techniques (PIV, PIT), numerical fluid flow and heat transfer (FLUENT, NASTRAN), validation, thermodynamics

Dekaban Fund Activity: Dekaban Fellow from September, 2003 to September, 2004

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Dekaban Fellow Profiles Name: Ewa Szeliga Institution: Warsaw University of Technology Department of Civil Engineering Title: Assistant Professor Address: ul. Ksiazkowa 9D, m. 912

03-134 Warsaw Poland

Phone: (+48 22) 660-6516 Fax: (+48 22) 825-6985 E-Mail: Education: Warsaw University of Technology, MSc ’92, PhD ’00

Research Interests: Numerical analysis and computer-aided design of

engineering structures, theory of elasticity and plasticity, damage mechanics, continuum mechanics, thermodynamics of irreversible processes

Dekaban Fund Activity: Dekaban Fellow from August, 2004 to February, 2005

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Appendix C Visitor Profiles Name: Aleksander Szwed

Former Dekaban Fellow (March, 2001-October, 2003)

Institution: Warsaw University of Technology Department of Civil Engineering Institute of Structural Mechanics Title: Assistant Professor Address: ul. Ksiazkowa 9D, m. 912

03-134 Warsaw Poland

Phone: (+48 22) 660-6516 Fax: (+48 22) 825-6985 E-Mail: a.szwed@il.pw.edu.pl Education: Warsaw University of Technology, MSc ’92, PhD ’00

Research Interests: Numerical analysis and computer-aided design of

engineering structures, theory of elasticity and plasticity, damage mechanics, continuum mechanics, thermodynamics of irreversible processes

Dekaban Fund Activity: Visited U-M in 2005 and worked with U-M associate

research scientist Maria Szerszen

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Visitor Profiles Name: Sherif El-Tawil Institution: University of Michigan

Department of Civil and Environmental Engineering Title: Associate Professor Address: 2374 G. G. Brown Building

Ann Arbor, MI 48109-2125 Phone: (734) 764-5617 Fax: (734) 764-4292 E-Mail: eltawil@umich.edu Education: Cornell University, PhD ’96

Cairo University, BS ’89, MS ‘92 Research Interests: Response of buildings and bridges to extreme loading,

computational simulation, grid computing technology, finite element analysis, constitutive modeling, macro-plasticity formulations, nonlinear solution techniques and visualization methods

Dekaban Fund Activity: Attended the 5th International Conference of AMCM:

"Analytical Models and New Concepts in Concrete and Masonry Structures” in Gliwice-Ustron, Poland in June, 2005. Also attended workshops on concrete materials and structures held in June, 2005 in Warsaw and Krakow, Poland.

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Visitor Profiles Name: Radoslaw L. Michalowski Institution: University of Michigan

Department of Civil and Environmental Engineering Title: Professor Address: 2364 G. G. Brown Building

Ann Arbor, MI 48109-2125 Phone: (734) 763-2146 Fax: (734) 764-4292 E-Mail: rlmich@umich.edu Education: Institute of Fundamental Technological Research, Warsaw,

and Polyt. Univ. Poznan, PhD ’80 Polytechnic University Poznan, MSc ’74

Research Interests: Geomechanics Dekaban Fund Activity: Dekaban Program coordinator; visited WUT in June, 2005;

held meetings with the WUT Dekaban Committee, and with several departments

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Visitor Profiles Name: Andrzej Nowak Institution: Currently at:

Department of Civil Engineering University of Nebraska (previously at University of Michigan)

Title: Robert W. Brightfelt Professor of Engineering Address: W181 Nebraska Hall

Lincoln, NE 68588-0531

Phone: (402) 472-1376 Fax: (402) 472-8934 E-Mail: anowak2@unl.edu Education: Warsaw University of Technology, MSc ’70, PhD ’75 Research Interests: Structural reliability; bridge structures; code optimization;

human error Dekaban Fund Activity: Former Dekaban Program coordinator; faculty visitor to

WUT; taught a course on Reliability of Structures at WUT from February to June, 2005. Attended a workshop on concrete materials and structures held in June, 2005 in Warsaw and Krakow, Poland.

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U-M Visitor Profiles Name: Maria Szerszen Institution: University of Michigan College of Engineering

Department of Civil and Environmental Engineering Title: Associate Research Scientist Address: 2372 G. G. Brown Building

Ann Arbor, MI 48109-2125 Phone: (734) 764-4462 Fax: (734) 764-4292 E-Mail: mariasz@umich.edu Education: Cracow University of Technology, MSc ’78, PhD ’93

Research Interests: Concrete structures, fatigue of concrete, bridge structures Dekaban Fund Activity: Assisted in the planning of the Dekaban Program activities;

coordinated activities for the Dekaban Fellows.

Appendix D Dekaban Fund Endowment Agreement

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Appendix E Dekaban Fund Website Address The Web address for the Dekaban Program at the University of Michigan is http://www.engin.umich.edu/ipe/intpartners/warsaw.html and at the Warsaw University of Technology, it is http://www-personal.engin.umich.edu/~rogaj/dekaban/.

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Appendix F

Abstracts of Publications Related to U-M by the Dekaban Fellows

RESISTANCE AND LIMIT STATE FUNCTIONS FOR ECCENTRICALLY LOADED COLUMNS

M.M. Szerszen, A. Szwed, A.S. Nowak;

ACI Structural Journal, 2005

Abstract The paper presents the development of closed-form formulas for the ultimate limit state functions for eccentrically loaded short reinforced concrete columns. Moment vs. compressive force interaction diagram is derived as a function of eccentricity, section geometry and material properties. The behavior of concrete and reinforcing steel is modeled according to ACI 318-02. The formulas for resistance are derived based on the sectional force equilibrium and strain compatibility. The resulting closed-form solutions for column resistance are used as input for numerical simulations and the reliability analysis. Rectangular cross sections are considered with two reinforcement layers. The interaction diagram is subdivided into segments depending on the mode of failure, from the ideal axial compression, through pure flexure, including the various cases of strain in reinforcing steel. Two types of section are considered depending on size of the cross section. ________________________________________________________________________

RELIABILITY ANALYSIS FOR ECCENTRICALLY LOADED COLUMNS

M.M. Szerszen, A. Szwed, A.S. Nowak

ACI Structural Journal, 2005

Abstract Paper presents the reliability analysis for eccentrically loaded RC columns, based on new improved statistical data for materials. The strength limit state functions were developed for the reinforced rectangular columns in the companion paper, depending on the cross section size, reinforcement ratio and load eccentricity. The calculations are performed for for cast-in-place and plant cast columns made of ordinary concrete and high strength concrete. The statistical parameters of resistance are calculated using Monte Carlo simulations, using the developed closed-form solutions. Sensitivity analysis is performed to determine the design parameters that have the highest influence on the reliability index. Reliability surfaces are developed as a function of load ratio and normalized load eccentricity or tensile strain in steel. The required strength reduction factor is calculated

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for a predetermined target reliability index. The strength reduction factor for RC columns is proposed depending on the reinforcement ratio. ________________________________________________________________________

CALIBRATION OF THE DESIGN CODE FOR CURVED STEEL I-GIRDER BRIDGES

Piotr J. Podhorecki, Andrzej S. Nowak, Aleksander Szwed, Pascal Laumet

9th International Conference on Structural Safety and Reliability, ICOSSAR 2005, Rome

June, 2005 Summary The paper deals with the calibration of the design code for curved steel I-girder bridges with the objective to determine resistance factors. The calibration procedure included the selection of representative structures, the identification of the load and resistance parameters, the formulation of the limit state functions, the selection of the target reliability index, and the calculation of resistance factors. Three representative bridges were selected. Advanced finite element analysis was performed and the results were compared with the design (nominal) values. The main conclusion is that the same resistance factors can be used for straight and curved girder bridges. ________________________________________________________________________

RELIABILITY ANALYSIS FOR BRIDGE SUBSTRUCTURES

Aleksander Szwed, Andrzej S. Nowak, James L. Withiam 9th International Conference on Structural Safety and Reliability, ICOSSAR 2005, Rome

June, 2005 Summary The objective of this paper is to develop a reliability analysis procedure for the LRFD design provisions of bridge substructures. The considered types include inverted T-type retaining walls, flexible cantilever walls, anchored walls and bridge abutments. The reliability analysis is applied to determine the relationship between the major design parameters and reliability index. The load components considered include dead load, vertical and horizontal earth pressure, earth surcharge, and vehicle live load. Several limit states are considered: foundation bearing capacity, sliding, overturning, anchor pullout, passive resistance. The analyses show that the most important parameter in the reliability analysis is the effective stress friction angle of the soil. The reliability indices are calculated using Monte Carlo simulations for a typical retaining structures and bridge abutment. The results of the sensitivity analysis indicate that reliability index is most sensitive with regard to resistance factor and horizontal earth pressure factor. ________________________________________________________________________

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RELIABILITY-BASED SENSITIVITY ANALYSIS OF RC COLUMNS RESISTANCE

Maria M. Szerszen, Andrzej S. Nowak, Aleksander Szwed

9th International Conference on Structural Safety and Reliability, ICOSSAR 2005, Rome

June, 2005 Summary Paper presents the reliability analysis of RC columns subjected to eccentric load. Reliability analysis is based on new statistical parameters for materials (concrete and reinforcing steel). The load factors are taken according to ACI 318-02 “Building Code Requirements for Structural Concrete”. Developed closed-form sectional resistance formulas for eccentrically loaded columns are used in reliability analysis. Moment-compressive force interaction curve is described for sections depending on the mode of material failure. The proposed approach allows for creation of uniform reliability surface covering all design cases, from axial compression to pure flexure. In that way, reliability index can be expressed in terms of eccentricity of load or tensile strains in reinforcement. ________________________________________________________________________

RELIABILITY ANALYSIS FOR ECCENTRICALLY LOADED COLUMNS

Maria M. Szerszen, Aleksander Szwed, Andrzej S. Nowak

ACI Structural Journal, Vol. 102, No. 5, September, 2005, pp. 676-688 Summary This paper presents reliability analysis for eccentrically loaded reinforced concrete (RC) columns, based on new improved statistical data for the constituent materials. The strength limit state functions were developed for reinforced rectangular columns, depending on the cross section size, reinforcement ratio, and load eccentricity. For a known eccentricity condition, closed-form solutions for the corresponding force-moment strength in the interaction diagram were developed. The calculations for cast-in-place and plant-cast columns made of normal concrete and high-strength concrete were performed. The statistical parameters of resistance were calculated using Monte Carlo simulations. Sensitivity analyses were performed to determine the design parameters that have the highest influence on the reliability index. Many two- and three-dimensional plots were generated to show the reliability index versus concrete strength, reinforcement ratio, load combination, normalized eccentricity, and tensile strain in steel. The required strength reduction factor is calculated for a predetermined target reliability index to achieve accepted level of structural safety. The strength reduction factor for RC columns is proposed in a convenient form for design procedures, depending on the tensile strain in steel and the reinforcement ratio.

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RELIABILITY MODELS FOR BRIDGE SUBSTRUCTURES

A. Szwed, A.S. Nowak, F. ASCE, J.L. Withiam

9th ASCE Joint Specialty Conference on Probabilistic Mechanics and Structural

Reliability; July 26-28, 2004, Albuquerque, New Mexico Abstract The paper objective is to develop a reliability analysis procedure for retaining walls and bridge abutments, and apply it to determine the relationship between the major design parameters and reliability index. The load components include dead load, vertical and horizontal earth pressure, surcharge, and live load. Three limit states are considered: bearing capacity of the soil, sliding and overturning. The most important parameter in the reliability analysis is the effective stress friction angle of the soil. The reliability indices are calculated using Monte Carlo simulations for a typical retaining wall and a typical bridge abutment. The results of the sensitivity analysis indicate that reliability index is most sensitive with regard to resistance factor and horizontal earth pressure. ________________________________________________________________________

DETERMINATION OF RESISTANCE FACTORS FOR DESIGN OF

ECCENTRICALLY LOADED COLUMNS ACCORDING AMERICAN ACI 318 CODE

A. Szwed, M.M. Szerszeń, A.S. Nowak

50th Scientific Conference of Civil and Environmental Engineering Committee of Polish Academy of Sciences and Scientific Committee of Polish Association of Civil Engineers,

"KRYNICA 2004", September 12-17, 2004, Krynica, Poland Abstract Paper presents the reliability analysis of eccentrically loaded reinforced concrete columns. The analysis was performed according to ACI 318 code provisions for possible change of resistance factors. Change of the load model in the code, and new statistical parameters for reinforcing steel and concrete are utilized in estimation of resistance factors. New closed-form sectional resistance formulas were used in development of the new limit state function for reliability analysis. The proposed approach allows for creation of reliability surface covering all design cases, from axial compression to pure flexure. Several concrete strengths, reinforcement ratios and cross-sections were investigated. Plots of obtained resistance factor versus load eccentricity and load combinations were prepared. Influence of basic parameters was discussed and conclusions were drawn from the analysis. The results serve as a basis for selection of new resistance factors for reinforced concrete columns.

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RELIABILITY-BASED SENSITIVITY ANALYSIS OF R/C COLUMNS RESISTANCE

M.M. Szerszen, A.S. Nowak, A. Szwed

9th ASCE Joint Specialty Conference on Probabilistic Mechanics and Structural

Reliability; July 26-28, 2004, Albuquerque, New Mexico Abstract Paper presents the reliability analysis of RC columns subjected to eccentric load. Reliability analysis includes new load model according to ACI 318-02 “Building Code Requirements for Structural Concrete” provisions, and is based on new statistical parameters for materials (concrete and reinforcing steel). Developed closed-form sectional resistance formulas for eccentrically loaded columns are used in reliability analysis. Moment-compressive force interaction curve is described for sections depending on the mode of material failure. The proposed approach allows for creation of uniform reliability surface covering all design cases, from axial compression to pure flexure. In that way, reliability index can be expressed in terms of eccentricity of load or tensile strains in reinforcement. This approach can serve as a better basis for selection of new resistance factors for analyzed columns. ________________________________________________________________________

INITIAL OPTIMIZATION OF SELF-PIERCING RIVETING PROCESS BY MEANS OF FEM

Robert Cacko, Piotr Czyżewski, Andrzej Kocańda

Paper was presented at the 10th International Conference on Metal Forming 2004, and

subsequently published in a special edition of the journal Steel Grips Summary Although SPR – Self Piercing Riveting as a joining technique of sheets constantly increases its importance, especially in the automotive industry, there is still lack of analytical description of mechanism of forming a joint. The reason is very simple: it is very difficult to get insight into the joint during forming process and following that evaluate how stress field develops. The only way to analyze SPR joint during forming is to perform physical or/and numerical modeling. However the problem is not trivial because of high level of localized deformation combined with material fracture. In detail, there are some unknown parameters exist like moment of separation of upper sheet. These effects significantly influence reliability of both analytical techniques. So far, preliminary simulations have been carried out using simple assumptions but without or with limited relation to real processes. Hence stress field after unloading, which

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determines strength of a joint, still remains generally unknown. In this paper initial trials carried out to optimize the SPR process using simple algorithms implemented into commercial FEM codes are presented. Optimization of the FEM model refer to both real shape of a joint and force history. Basing on They are to be the beginnig to implement more sophisticated model taking into account complex stress state in the joint and relation with material separation. So far the criteria of upper sheet thickness before separation Commercial FEM codes: Abaqus and MSC/Marc-Mentat are used for the SPR process simulation. ________________________________________________________________________

EXPERIMENTAL VALIDATION OF BEM CODE

ANALYSIS OF BUBBLE SPLITTING IN A TIP VORTEX FLOW

M. Rebow, J. Choi, J.-K. Choi, G.L. Chahine, S.L. Ceccio

11TH INTERNATIONAL SYMPOSIUM ON FLOW VISUALIZATION August 9-12, 2004, University of Notre Dame, Notre Dame, Indiana, USA

Summary The growth and collapse of a cavitation bubble within the core of a line vortex is examined experimentally and numerically. This paper presents some preliminary results. A steady line vortex is formed downstream of a hydrofoil mounted in the test section of the U-M 9-Inch Water Tunnel. A laser is used to initiate a nucleus in the core of the vortex. This nucleus grows and collapses as it experiences a reduction and recovery of the local static pressure. This pressure change is produced when the vortical flow in the test section passes through a reduction in area. Particle image velocimetry is used to measure the axial velocity and average tangential velocity of the tip vortex. Images of the bubble’s growth, deformation and splitting are captured with a pulse-synchronize camera. The results are then compared with those obtained with the boundary element method (BEM) code 2DYNAFS _, which describes large free surface deformations in an axisymmetric potential flow to validate the extreme deformations and splitting model of the bubble. The experimentally observed and numerically predicted bubble dynamics are compared. ________________________________________________________________________

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