Dr. Eyassu Woldesenbet
 Assistant Professor

Professor for the ME 4783 Composite Materials: MANUFACTURING, PROPERTIES & DESIGN  class.
Office Hours: T,Th 9:00-11:30, 2:30 - 5:00.

Department of Mechanical Engineering                                                                               Department of Mechanical Engineering
Room 1419D                                                                                                                                                 ROOM 18
Louisiana State University                                                                                                  Southern University
Baton Rouge, LA 70803-6413                                                                                            Baton Rouge, LA 70813
Phone: (225) 578-5900                                                                                                      (225) 771-4701
FAX: (504) 578-5924                                                                                                        (225) 771-4877
E-mail address: woldesen@me.lsu.edu                                                                                woldesen@engr.subr.edu
 

Don't hesitate to contact me if you have any questions about this class.

RESEARCH INTERESTS/PROJECTS
High Strain Rate and Mechanics & Design of Composite Materials,
Rehabilitation of Structures using Composites
Composite Sandwich Structures
Analysis of Grid Stiffened Compsite Cylinders

B.Sc., Cornell University,1992
M.M.E., University of Delaware, 1995
Ph.D., University of Delaware, 1998
Visiting Assistant Professor, Winona State University, 1997-1998


Today, materials are being selected and used without the necessary property data to accurately predict their behavior under impact at extreme temperatures.  For applications involving high strain rates and extreme temperatures, fundamental test data and experimental models to predict material properties are needed.  Our research addresses this deficit and provides predictive capability to ensure that designs are optimized for structural integrity and weight efficiency including when the structure is subjected to dynamic loading at extreme temperatures.  A Split-Hopkinson Pressure Bar Apparatus is built to conduct the high strain rate tests. Excellent mechanical properties such as high-strength, low-weight, fatigue life, and impact resistance, as well as advanced manufacturing methods and tailor ability of the lay-up make polymer matrix composites attractive candidates for use in several performance-oriented structures.  One use of composite materials is in the oil industry, where composite sucker rods have just started replacing steel rods in rod pumping which is the most common lift technology used in domestic oil production. These composite sucker rods consist of composite rods and steel endfittings.  However, these composite sucker rods are experiencing fatigue failure. Our research focuses on resolving the fatigue failure from two directions.  These are material selection/ improvement, and the design of the composite rods and the steel endfittings.  Another on-going research is the analysis of grid stiffened graphite/epoxy composite cylinders.  Buckling analysis is being performed including analytical, experimental, and numerical (FEM).  Results show that the stiffner geometries can be optimized. More than 40 percent of the Nation's 575,000 highway bridges are functionally obsolete or structurally deficient. Because of the prohibitive cost of replacing all of the sub-standard structures, innovative techniques for rehabilitating deteriorating structures are needed.  One particular type of innovative technique is the external strengthening of concrete structures utilizing bonded composite materials. We are working to formulate the effects of surface preparation of the concrete, constituent (composite, concrete, and adhesive) type, and concrete strength, on the overall bond strength; and study the fatigue properties of the (composite material and concrete) bond.  In addition, the effect of severe environment on the bond will be investigated.  These experiments will help to develop a numerical model, using finite element analysis. Sandwich structure materials are widely used in structural application.  Their importance in weight sensitive applications is evident by their extensive use in aerospace sector.  Construction of sandwiches in two distinct parts, namely, core and skins, provides greater design flexibility.  Suitable combination of core and skin materials can be found to meet the predetermined performance requirements.  The popular choices of core materials include honeycomb structures and rigid and flexible foams having open pore or close pole structure.  The aim of the investigation undertaken is to develop a better understanding of rigid particle filled polymeric materials for their potential use as core in sandwich materials.  This will be useful in reducing the design tolerances leading to weight saving and better estimation on safety aspects of the material under the given conditions.
 
 
 
 
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