1.結構的位移 Displacements of structures
線位移：結構某點移動的距離（）Linear displacements or translation: the distance of movement of a point alone a line;
角位移（轉角）：結構構件某截面轉的角度（）Angular displacement or rotation:sectional rotation of a member of a structure.
相對（線）位移：兩點之間距離變化
Relative linear displacement: the change of the distance between 2 points.
相對角位移（轉角）：兩截面之間夾角變化 Relative angular displacement:the change of the angle between 2 sections.
2.廣義位移的概念 Generalized displacements
為便于進行理論分析和公式推導，將所討論的各種結構位移用統(tǒng)一的符號來表示—，稱為廣義位移。For the convenience of the proceeding of theoretical analysis and derivation of formulae, we denote all kinds of displacements by , which is termed as generalized displacements
注Remark：廣義位移可以看成為代表位移的抽象符號，在具體問題中表示具體位移. Generalized displacements may be looked at as abstract sign, which represents concrete displacement in concrete problems.