Fracture or fatigue (i.e. cracking due to large and repeated loads) in steel structures often results in great damage to property as well as loss of life. Recently, structural fracture has been observed in the I-35 bridge collapse in Minneapolis and to over 100 buildings that experienced shaking in the 1994 Northridge Earthquake in the Los Angeles area. Motivated by these events, this project will develop improved methods to predict fracture in steel structures such as bridges, buildings, industrial facilities, or ships. The research focus will be on understanding a special type of ductile fracture that originates on the surfaces or corners of structures. The investigation will involve a program of laboratory testing and complementary finite element computer analysis to evaluate critical values of stresses and strains that cause surface fracture in structural steel. The project will culminate in the development of computational models that will enable engineers and scientists to accurately calculate and mitigate the risk of fracture in steel structures.
The models developed through this research will enable the design and construction of buildings, bridges and other structures that are safer and more fracture resistant. To disseminate and promote use of the research findings, the principal investigators will educate engineers through workshops, training courses and technical publications. In addition, the research project will form the basis of doctoral theses for two graduate students who, equipped with the advanced knowledge created during this research, will further develop and disseminate the research findings.
