... ∂/∂xk Material derivative operator b or bi Body force (force per unit mass) p or pi Body force (force per unit volume) f or fi Surface force (force per unit area) V, V0 Current and referential ... Transformation table for general plane stress 69 82 4.1 Transformation table for general plane strain 126 5.1 5.2 Fundamental equations in global and local forms ... previous editions, the thirdedition is an outgrowth of course notes and problems used to teach the topic to senior undergraduate or first year graduate students The impetus to the third edition...