C. Dascalu * G. A. Maugin The volume presents recent developments in the This special issue aims at bringing together recent theory of defects and the mechanics of material forces. developmentsinMaterialMechanicsandthemoreclas- Most of the contributions were presented at the Inter- sical Defect Mechanics approaches. The contributions national Symposium on Defect and Material Forces are highlighting recent research on topics like: fracture (ISDMM2007), held in Aussois, France, March 25- and damage, electromagnetoelasticity, plasticity, dis- 29, 2007. tributed dislocations, thermodynamics, poroelasticity, Originated in the works of Eshelby, the Material or generalized continua, structural optimization, conser- Con gurational Mechanics experienced a remarkable vationlawsandsymmetries,multiscaleapproachesand revival over the last two decades. When the mechanics numerical solution strategies. ofcontinuaisfullyexpressedonthematerialmanifold, We expect the present volume to be a valuable it captures the material inhomogeneities. The driving resource for researchers in the eld of Mechanics of (material) forces on inhomogeneities appear naturally Defects in Solids. in this framework and are requesting for constitutive We dedicate this special issue to the memory of modeling of the evolution of inhomogeneities through the late Professor George Herrmann (1921-2007).