Probing the mysteries of cracks and stresses
Diving into a pool from a few feet up allows you to enter the water smoothly and painlessly, but jumping from a bridge can lead to a fatal impact. The water is the same in each case, so why is the effect of hitting its surface so different?This seemingly basic question is at the heart of complex research by a team in MIT’s Department of Nuclear Science and Engineering (NSE) that studied how materials react to stresses, including impacts. The findings could ultimately help explain phenomena as varied as the breakdown of concrete under sudden stress and the effects of corrosion on various metal surfaces.Using a combination of computer modeling and experimental tests, the researchers studied one specific type of stress — in a defect called a screw dislocation — in one kind of material, an iron crystal lattice. But the underlying explanation, the researchers say, may have broad implications...