In the spring semester of 2002, Dr. Woldesenbet and I gave a hand-on laboratory course: Materials of Engineering Laboratory, to the junior undergraduate students at the Louisiana State University. In this Blog, I am also adding some state-of-the-art techniques for materials laboratory.
Class schedule:
Granular materials deserve being investigated as this has been the case with liquids, gases and elastic materials.
cellular metal: space is divided into distinct cells. The boundaries of these cells are made of solid metal, the interior are voids. Ideally, the individual cells are all separated from each other by metal but often this restriction is relaxed
plastic bonded explosives are composites containing energetic grains, ranging in size from less than one to a few hundred micrometers, embedded in a matrix of high-polymer binder.
Experimentally, loading to a mechanical system can be applied either through the displacement control or the force control.
However, the responses of the system can only be measured in displacements, and hence strains.
This blog is on material behaviors under extreme loading.
an interesting puzzle for fun:
Lame’s classical solution for an elastic 2D plate, with a hole of radius a and uniform tensile stress applied at the far field, gives a stress concentration factor (SCF) of two at the edge of the hole. This SCF=2 is independent of the hole radius.
Consider what happened to this concentration factor if the radius a approaches infinitely small. The SCF is independent of a, so it remains equal to two even when the hole disappears.
This blog focuses on the behaviors of energetic materials (such as solid rocket propellants, high explosives), shock waves, and explosions. And also on the protections, from the design of protecting materials and structures.
Lecture notes:
The following is a link to a FEMA course
