T1 process

A T1 process is a topological rearrangement process of the first kind for four discrete objects such as bubbles, drops, cells, etc. The four objects are initially arranged in a plane in the following way. Objects A and B are in contact and objects C and D are on either side of the AB group and touching both A and B. The T1 process consists in breaking the contact between A and B and establishing the contact between C and D.

Materials made of these objects have a number of similar rheological properties. Among these, plasticity allows them to be deformed irreversibly. For such materials, such irreversible deformations arise from the possibility to rearrange their constitutive objects. Thus, the T1 process is the major mesoscopic ingredient of plasticity for these materials.