ANALYSIS OFSTRESSAND STRAIN 6 Original element ( known element) Example 1 Plot the known elements of point A, B C sho own In the following figures 92g O M
6、Original element（known element）： Example 1 Plot the known elements of point A、B、C shown in the following figures. tzx P P A A s sx x M P x y z B C s sx x B t xz C t xy t yx
六、原始单元体(已知单元体): [例1]画出下列图中的A、B、C点的已知单元体。 P soe P y ● M xz
tzx 六、原始单元体（已知单元体）： [例1] 画出下列图中的A、B、C点的已知单元体。 P P A A s sx x M P x y z B C s sx x B t xz C t xy t yx
ANALYSIS OFSTRESSAND STRAIN 7、 Principal element、 principal planes、 principal stresses: y ① Principal element: y The element in which the shearing stresses in side planes are all zero 2 Principal Planes: The planes on which the shearing stresses are zero x 3 Principal stresses Normal stresses acting on the principle planes 4 convention of the order for three principal stresses In magnitude of the algebraic value 12a2=o3
7、Principal element、principal planes、principal stresses： Principal element： The element in which the shearing stresses in side planes are all zero. Principal Planes： The planes on which the shearing stresses are zero. Principal stresses： Normal stresses acting on the principle planes. convention of the order for three principal stresses: In magnitude of the algebraic value， s1 s 2 s 3 s1 s2 s3 x y z sx sy sz
七、主单元体、主平面、主应力: G 主单元体( Principal bidy): 各侧面上剪应力均为零的单元体。 色主平面( Principal plane) 剪应力为零的截面。 主应力( Principal Stress): 主平面上的正应力 a主应力排列规定:按代数值大小, 01202203
七、主单元体、主平面、主应力： 主单元体(Principal bidy)： 各侧面上剪应力均为零的单元体。 主平面(Principal Plane)： 剪应力为零的截面。 主应力(Principal Stress ）： 主平面上的正应力。 主应力排列规定：按代数值大小， s1 s 2 s 3 s1 s2 s3 x y z sx sy sz
ANALYSIS OFSTRESSAND STRAIN 5 State of the triaxialStress State of stress that all the three principal stresses are not equal to zero 6 State of the biaxial stress State of stress that one principal stress is equal to zero o State of the uniaxial stress State of stress that one principal stress is not equal to zero Ox B
State of the uniaxial stress: State of stress that one principal stress is not equal to zero. State of the biaxial stress： State of stress that one principal stress is equal to zero. State of the triaxial Stress : State of stress that all the three principal stresses are not equal to zero. A s sx x tzx s sx x B t xz